Commit Graph

13677 Commits

Author SHA1 Message Date
Linus Torvalds
a382b06d29 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
 "arm64:

   - Fix a couple of bugs affecting pKVM's PSCI relay implementation
     when running in the hVHE mode, resulting in the host being entered
     with the MMU in an unknown state, and EL2 being in the wrong mode

  x86:

   - Set RFLAGS.IF in C code on SVM to get VMRUN out of the STI shadow

   - Ensure DEBUGCTL is context switched on AMD to avoid running the
     guest with the host's value, which can lead to unexpected bus lock
     #DBs

   - Suppress DEBUGCTL.BTF on AMD (to match Intel), as KVM doesn't
     properly emulate BTF. KVM's lack of context switching has meant BTF
     has always been broken to some extent

   - Always save DR masks for SNP vCPUs if DebugSwap is *supported*, as
     the guest can enable DebugSwap without KVM's knowledge

   - Fix a bug in mmu_stress_tests where a vCPU could finish the "writes
     to RO memory" phase without actually generating a write-protection
     fault

   - Fix a printf() goof in the SEV smoke test that causes build
     failures with -Werror

   - Explicitly zero EAX and EBX in CPUID.0x8000_0022 output when
     PERFMON_V2 isn't supported by KVM"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Explicitly zero EAX and EBX when PERFMON_V2 isn't supported by KVM
  KVM: selftests: Fix printf() format goof in SEV smoke test
  KVM: selftests: Ensure all vCPUs hit -EFAULT during initial RO stage
  KVM: SVM: Don't rely on DebugSwap to restore host DR0..DR3
  KVM: SVM: Save host DR masks on CPUs with DebugSwap
  KVM: arm64: Initialize SCTLR_EL1 in __kvm_hyp_init_cpu()
  KVM: arm64: Initialize HCR_EL2.E2H early
  KVM: x86: Snapshot the host's DEBUGCTL after disabling IRQs
  KVM: SVM: Manually context switch DEBUGCTL if LBR virtualization is disabled
  KVM: x86: Snapshot the host's DEBUGCTL in common x86
  KVM: SVM: Suppress DEBUGCTL.BTF on AMD
  KVM: SVM: Drop DEBUGCTL[5:2] from guest's effective value
  KVM: selftests: Assert that STI blocking isn't set after event injection
  KVM: SVM: Set RFLAGS.IF=1 in C code, to get VMRUN out of the STI shadow
2025-03-09 09:04:08 -10:00
Paolo Bonzini
ea9bd29a9c Merge tag 'kvm-x86-fixes-6.14-rcN.2' of https://github.com/kvm-x86/linux into HEAD
KVM x86 fixes for 6.14-rcN #2

 - Set RFLAGS.IF in C code on SVM to get VMRUN out of the STI shadow.

 - Ensure DEBUGCTL is context switched on AMD to avoid running the guest with
   the host's value, which can lead to unexpected bus lock #DBs.

 - Suppress DEBUGCTL.BTF on AMD (to match Intel), as KVM doesn't properly
   emulate BTF.  KVM's lack of context switching has meant BTF has always been
   broken to some extent.

 - Always save DR masks for SNP vCPUs if DebugSwap is *supported*, as the guest
   can enable DebugSwap without KVM's knowledge.

 - Fix a bug in mmu_stress_tests where a vCPU could finish the "writes to RO
   memory" phase without actually generating a write-protection fault.

 - Fix a printf() goof in the SEV smoke test that causes build failures with
   -Werror.

 - Explicitly zero EAX and EBX in CPUID.0x8000_0022 output when PERFMON_V2
   isn't supported by KVM.
2025-03-09 03:44:06 -04:00
Ingo Molnar
6914f7e2e2 x86/mm: Define PTRS_PER_PMD for assembly code too
Andy reported the following build warning from head_32.S:

  In file included from arch/x86/kernel/head_32.S:29:
  arch/x86/include/asm/pgtable_32.h:59:5: error: "PTRS_PER_PMD" is not defined, evaluates to 0 [-Werror=undef]
       59 | #if PTRS_PER_PMD > 1

The reason is that on 2-level i386 paging the folded in PMD's
PTRS_PER_PMD constant is not defined in assembly headers,
only in generic MM C headers.

Instead of trying to fish out the definition from the generic
headers, just define it - it even has a comment for it already...

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/Z8oa8AUVyi2HWfo9@gmail.com
2025-03-08 00:09:09 +01:00
Alexey Kardashevskiy
3e385c0d6c virt: sev-guest: Move SNP Guest Request data pages handling under snp_cmd_mutex
Compared to the SNP Guest Request, the "Extended" version adds data pages for
receiving certificates. If not enough pages provided, the HV can report to the
VM how much is needed so the VM can reallocate and repeat.

Commit

  ae596615d9 ("virt: sev-guest: Reduce the scope of SNP command mutex")

moved handling of the allocated/desired pages number out of scope of said
mutex and create a possibility for a race (multiple instances trying to
trigger Extended request in a VM) as there is just one instance of
snp_msg_desc per /dev/sev-guest and no locking other than snp_cmd_mutex.

Fix the issue by moving the data blob/size and the GHCB input struct
(snp_req_data) into snp_guest_req which is allocated on stack now and accessed
by the GHCB caller under that mutex.

Stop allocating SEV_FW_BLOB_MAX_SIZE in snp_msg_alloc() as only one of four
callers needs it. Free the received blob in get_ext_report() right after it is
copied to the userspace. Possible future users of snp_send_guest_request() are
likely to have different ideas about the buffer size anyways.

Fixes: ae596615d9 ("virt: sev-guest: Reduce the scope of SNP command mutex")
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250307013700.437505-3-aik@amd.com
2025-03-07 14:09:33 +01:00
Pawan Gupta
9af9ad85ac x86/speculation: Add a conditional CS prefix to CALL_NOSPEC
Retpoline mitigation for spectre-v2 uses thunks for indirect branches. To
support this mitigation compilers add a CS prefix with
-mindirect-branch-cs-prefix. For an indirect branch in asm, this needs to
be added manually.

CS prefix is already being added to indirect branches in asm files, but not
in inline asm. Add CS prefix to CALL_NOSPEC for inline asm as well. There
is no JMP_NOSPEC for inline asm.

Reported-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250228-call-nospec-v3-2-96599fed0f33@linux.intel.com
2025-03-03 12:04:43 +01:00
Pawan Gupta
010c4a461c x86/speculation: Simplify and make CALL_NOSPEC consistent
CALL_NOSPEC macro is used to generate Spectre-v2 mitigation friendly
indirect branches. At compile time the macro defaults to indirect branch,
and at runtime those can be patched to thunk based mitigations.

This approach is opposite of what is done for the rest of the kernel, where
the compile time default is to replace indirect calls with retpoline thunk
calls.

Make CALL_NOSPEC consistent with the rest of the kernel, default to
retpoline thunk at compile time when CONFIG_MITIGATION_RETPOLINE is
enabled.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250228-call-nospec-v3-1-96599fed0f33@linux.intel.com
2025-03-03 12:04:42 +01:00
Sean Christopherson
fb71c79593 KVM: x86: Snapshot the host's DEBUGCTL in common x86
Move KVM's snapshot of DEBUGCTL to kvm_vcpu_arch and take the snapshot in
common x86, so that SVM can also use the snapshot.

Opportunistically change the field to a u64.  While bits 63:32 are reserved
on AMD, not mentioned at all in Intel's SDM, and managed as an "unsigned
long" by the kernel, DEBUGCTL is an MSR and therefore a 64-bit value.

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: stable@vger.kernel.org
Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250227222411.3490595-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-02-28 09:17:45 -08:00
Linus Torvalds
ff1848d81c Merge tag 'perf_urgent_for_v6.14_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf fixes from Borislav Petkov:

 - Explicitly clear DEBUGCTL.LBR to prevent LBRs continuing being
   enabled after handoff to the OS

 - Check CPUID(0x23) leaf and subleafs presence properly

 - Remove the PEBS-via-PT feature from being supported on hybrid systems

 - Fix perf record/top default commands on systems without a raw PMU
   registered

* tag 'perf_urgent_for_v6.14_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Ensure LBRs are disabled when a CPU is starting
  perf/x86/intel: Fix ARCH_PERFMON_NUM_COUNTER_LEAF
  perf/x86/intel: Clean up PEBS-via-PT on hybrid
  perf/x86/rapl: Fix the error checking order
2025-02-16 10:41:50 -08:00
Paolo Bonzini
d3d0b8dfe0 Merge tag 'kvm-x86-fixes-6.14-rcN' of https://github.com/kvm-x86/linux into HEAD
KVM fixes for 6.14 part 1

 - Reject Hyper-V SEND_IPI hypercalls if the local APIC isn't being emulated
   by KVM to fix a NULL pointer dereference.

 - Enter guest mode (L2) from KVM's perspective before initializing the vCPU's
   nested NPT MMU so that the MMU is properly tagged for L2, not L1.

 - Load the guest's DR6 outside of the innermost .vcpu_run() loop, as the
   guest's value may be stale if a VM-Exit is handled in the fastpath.
2025-02-14 19:08:35 -05:00
Ashish Kalra
409f45387c x86/sev: Fix broken SNP support with KVM module built-in
Fix issues with enabling SNP host support and effectively SNP support
which is broken with respect to the KVM module being built-in.

SNP host support is enabled in snp_rmptable_init() which is invoked as
device_initcall(). SNP check on IOMMU is done during IOMMU PCI init
(IOMMU_PCI_INIT stage). And for that reason snp_rmptable_init() is
currently invoked via device_initcall() and cannot be invoked via
subsys_initcall() as core IOMMU subsystem gets initialized via
subsys_initcall().

Now, if kvm_amd module is built-in, it gets initialized before SNP host
support is enabled in snp_rmptable_init() :

[   10.131811] kvm_amd: TSC scaling supported
[   10.136384] kvm_amd: Nested Virtualization enabled
[   10.141734] kvm_amd: Nested Paging enabled
[   10.146304] kvm_amd: LBR virtualization supported
[   10.151557] kvm_amd: SEV enabled (ASIDs 100 - 509)
[   10.156905] kvm_amd: SEV-ES enabled (ASIDs 1 - 99)
[   10.162256] kvm_amd: SEV-SNP enabled (ASIDs 1 - 99)
[   10.171508] kvm_amd: Virtual VMLOAD VMSAVE supported
[   10.177052] kvm_amd: Virtual GIF supported
...
...
[   10.201648] kvm_amd: in svm_enable_virtualization_cpu

And then svm_x86_ops->enable_virtualization_cpu()
(svm_enable_virtualization_cpu) programs MSR_VM_HSAVE_PA as following:
wrmsrl(MSR_VM_HSAVE_PA, sd->save_area_pa);

So VM_HSAVE_PA is non-zero before SNP support is enabled on all CPUs.

snp_rmptable_init() gets invoked after svm_enable_virtualization_cpu()
as following :
...
[   11.256138] kvm_amd: in svm_enable_virtualization_cpu
...
[   11.264918] SEV-SNP: in snp_rmptable_init

This triggers a #GP exception in snp_rmptable_init() when snp_enable()
is invoked to set SNP_EN in SYSCFG MSR:

[   11.294289] unchecked MSR access error: WRMSR to 0xc0010010 (tried to write 0x0000000003fc0000) at rIP: 0xffffffffaf5d5c28 (native_write_msr+0x8/0x30)
...
[   11.294404] Call Trace:
[   11.294482]  <IRQ>
[   11.294513]  ? show_stack_regs+0x26/0x30
[   11.294522]  ? ex_handler_msr+0x10f/0x180
[   11.294529]  ? search_extable+0x2b/0x40
[   11.294538]  ? fixup_exception+0x2dd/0x340
[   11.294542]  ? exc_general_protection+0x14f/0x440
[   11.294550]  ? asm_exc_general_protection+0x2b/0x30
[   11.294557]  ? __pfx_snp_enable+0x10/0x10
[   11.294567]  ? native_write_msr+0x8/0x30
[   11.294570]  ? __snp_enable+0x5d/0x70
[   11.294575]  snp_enable+0x19/0x20
[   11.294578]  __flush_smp_call_function_queue+0x9c/0x3a0
[   11.294586]  generic_smp_call_function_single_interrupt+0x17/0x20
[   11.294589]  __sysvec_call_function+0x20/0x90
[   11.294596]  sysvec_call_function+0x80/0xb0
[   11.294601]  </IRQ>
[   11.294603]  <TASK>
[   11.294605]  asm_sysvec_call_function+0x1f/0x30
...
[   11.294631]  arch_cpu_idle+0xd/0x20
[   11.294633]  default_idle_call+0x34/0xd0
[   11.294636]  do_idle+0x1f1/0x230
[   11.294643]  ? complete+0x71/0x80
[   11.294649]  cpu_startup_entry+0x30/0x40
[   11.294652]  start_secondary+0x12d/0x160
[   11.294655]  common_startup_64+0x13e/0x141
[   11.294662]  </TASK>

This #GP exception is getting triggered due to the following errata for
AMD family 19h Models 10h-1Fh Processors:

Processor may generate spurious #GP(0) Exception on WRMSR instruction:
Description:
The Processor will generate a spurious #GP(0) Exception on a WRMSR
instruction if the following conditions are all met:
- the target of the WRMSR is a SYSCFG register.
- the write changes the value of SYSCFG.SNPEn from 0 to 1.
- One of the threads that share the physical core has a non-zero
value in the VM_HSAVE_PA MSR.

The document being referred to above:
https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/revision-guides/57095-PUB_1_01.pdf

To summarize, with kvm_amd module being built-in, KVM/SVM initialization
happens before host SNP is enabled and this SVM initialization
sets VM_HSAVE_PA to non-zero, which then triggers a #GP when
SYSCFG.SNPEn is being set and this will subsequently cause
SNP_INIT(_EX) to fail with INVALID_CONFIG error as SYSCFG[SnpEn] is not
set on all CPUs.

Essentially SNP host enabling code should be invoked before KVM
initialization, which is currently not the case when KVM is built-in.

Add fix to call snp_rmptable_init() early from iommu_snp_enable()
directly and not invoked via device_initcall() which enables SNP host
support before KVM initialization with kvm_amd module built-in.

Add additional handling for `iommu=off` or `amd_iommu=off` options.

Note that IOMMUs need to be enabled for SNP initialization, therefore,
if host SNP support is enabled but late IOMMU initialization fails
then that will cause PSP driver's SNP_INIT to fail as IOMMU SNP sanity
checks in SNP firmware will fail with invalid configuration error as
below:

[    9.723114] ccp 0000:23:00.1: sev enabled
[    9.727602] ccp 0000:23:00.1: psp enabled
[    9.732527] ccp 0000:a2:00.1: enabling device (0000 -> 0002)
[    9.739098] ccp 0000:a2:00.1: no command queues available
[    9.745167] ccp 0000:a2:00.1: psp enabled
[    9.805337] ccp 0000:23:00.1: SEV-SNP: failed to INIT rc -5, error 0x3
[    9.866426] ccp 0000:23:00.1: SEV API:1.53 build:5

Fixes: c3b86e61b7 ("x86/cpufeatures: Enable/unmask SEV-SNP CPU feature")
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Message-ID: <138b520fb83964782303b43ade4369cd181fdd9c.1739226950.git.ashish.kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-14 18:39:19 -05:00
Sean Christopherson
c2fee09fc1 KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
Move the conditional loading of hardware DR6 with the guest's DR6 value
out of the core .vcpu_run() loop to fix a bug where KVM can load hardware
with a stale vcpu->arch.dr6.

When the guest accesses a DR and host userspace isn't debugging the guest,
KVM disables DR interception and loads the guest's values into hardware on
VM-Enter and saves them on VM-Exit.  This allows the guest to access DRs
at will, e.g. so that a sequence of DR accesses to configure a breakpoint
only generates one VM-Exit.

For DR0-DR3, the logic/behavior is identical between VMX and SVM, and also
identical between KVM_DEBUGREG_BP_ENABLED (userspace debugging the guest)
and KVM_DEBUGREG_WONT_EXIT (guest using DRs), and so KVM handles loading
DR0-DR3 in common code, _outside_ of the core kvm_x86_ops.vcpu_run() loop.

But for DR6, the guest's value doesn't need to be loaded into hardware for
KVM_DEBUGREG_BP_ENABLED, and SVM provides a dedicated VMCB field whereas
VMX requires software to manually load the guest value, and so loading the
guest's value into DR6 is handled by {svm,vmx}_vcpu_run(), i.e. is done
_inside_ the core run loop.

Unfortunately, saving the guest values on VM-Exit is initiated by common
x86, again outside of the core run loop.  If the guest modifies DR6 (in
hardware, when DR interception is disabled), and then the next VM-Exit is
a fastpath VM-Exit, KVM will reload hardware DR6 with vcpu->arch.dr6 and
clobber the guest's actual value.

The bug shows up primarily with nested VMX because KVM handles the VMX
preemption timer in the fastpath, and the window between hardware DR6
being modified (in guest context) and DR6 being read by guest software is
orders of magnitude larger in a nested setup.  E.g. in non-nested, the
VMX preemption timer would need to fire precisely between #DB injection
and the #DB handler's read of DR6, whereas with a KVM-on-KVM setup, the
window where hardware DR6 is "dirty" extends all the way from L1 writing
DR6 to VMRESUME (in L1).

    L1's view:
    ==========
    <L1 disables DR interception>
           CPU 0/KVM-7289    [023] d....  2925.640961: kvm_entry: vcpu 0
 A:  L1 Writes DR6
           CPU 0/KVM-7289    [023] d....  2925.640963: <hack>: Set DRs, DR6 = 0xffff0ff1

 B:        CPU 0/KVM-7289    [023] d....  2925.640967: kvm_exit: vcpu 0 reason EXTERNAL_INTERRUPT intr_info 0x800000ec

 D: L1 reads DR6, arch.dr6 = 0
           CPU 0/KVM-7289    [023] d....  2925.640969: <hack>: Sync DRs, DR6 = 0xffff0ff0

           CPU 0/KVM-7289    [023] d....  2925.640976: kvm_entry: vcpu 0
    L2 reads DR6, L1 disables DR interception
           CPU 0/KVM-7289    [023] d....  2925.640980: kvm_exit: vcpu 0 reason DR_ACCESS info1 0x0000000000000216
           CPU 0/KVM-7289    [023] d....  2925.640983: kvm_entry: vcpu 0

           CPU 0/KVM-7289    [023] d....  2925.640983: <hack>: Set DRs, DR6 = 0xffff0ff0

    L2 detects failure
           CPU 0/KVM-7289    [023] d....  2925.640987: kvm_exit: vcpu 0 reason HLT
    L1 reads DR6 (confirms failure)
           CPU 0/KVM-7289    [023] d....  2925.640990: <hack>: Sync DRs, DR6 = 0xffff0ff0

    L0's view:
    ==========
    L2 reads DR6, arch.dr6 = 0
          CPU 23/KVM-5046    [001] d....  3410.005610: kvm_exit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216
          CPU 23/KVM-5046    [001] .....  3410.005610: kvm_nested_vmexit: vcpu 23 reason DR_ACCESS info1 0x0000000000000216

    L2 => L1 nested VM-Exit
          CPU 23/KVM-5046    [001] .....  3410.005610: kvm_nested_vmexit_inject: reason: DR_ACCESS ext_inf1: 0x0000000000000216

          CPU 23/KVM-5046    [001] d....  3410.005610: kvm_entry: vcpu 23
          CPU 23/KVM-5046    [001] d....  3410.005611: kvm_exit: vcpu 23 reason VMREAD
          CPU 23/KVM-5046    [001] d....  3410.005611: kvm_entry: vcpu 23
          CPU 23/KVM-5046    [001] d....  3410.005612: kvm_exit: vcpu 23 reason VMREAD
          CPU 23/KVM-5046    [001] d....  3410.005612: kvm_entry: vcpu 23

    L1 writes DR7, L0 disables DR interception
          CPU 23/KVM-5046    [001] d....  3410.005612: kvm_exit: vcpu 23 reason DR_ACCESS info1 0x0000000000000007
          CPU 23/KVM-5046    [001] d....  3410.005613: kvm_entry: vcpu 23

    L0 writes DR6 = 0 (arch.dr6)
          CPU 23/KVM-5046    [001] d....  3410.005613: <hack>: Set DRs, DR6 = 0xffff0ff0

 A: <L1 writes DR6 = 1, no interception, arch.dr6 is still '0'>

 B:       CPU 23/KVM-5046    [001] d....  3410.005614: kvm_exit: vcpu 23 reason PREEMPTION_TIMER
          CPU 23/KVM-5046    [001] d....  3410.005614: kvm_entry: vcpu 23

 C: L0 writes DR6 = 0 (arch.dr6)
          CPU 23/KVM-5046    [001] d....  3410.005614: <hack>: Set DRs, DR6 = 0xffff0ff0

    L1 => L2 nested VM-Enter
          CPU 23/KVM-5046    [001] d....  3410.005616: kvm_exit: vcpu 23 reason VMRESUME

    L0 reads DR6, arch.dr6 = 0

Reported-by: John Stultz <jstultz@google.com>
Closes: https://lkml.kernel.org/r/CANDhNCq5_F3HfFYABqFGCA1bPd_%2BxgNj-iDQhH4tDk%2Bwi8iZZg%40mail.gmail.com
Fixes: 375e28ffc0 ("KVM: X86: Set host DR6 only on VMX and for KVM_DEBUGREG_WONT_EXIT")
Fixes: d67668e9dd ("KVM: x86, SVM: isolate vcpu->arch.dr6 from vmcb->save.dr6")
Cc: stable@vger.kernel.org
Cc: Jim Mattson <jmattson@google.com>
Tested-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/20250125011833.3644371-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-02-12 08:59:38 -08:00
Sean Christopherson
c631a2de7a perf/x86/intel: Ensure LBRs are disabled when a CPU is starting
Explicitly clear DEBUGCTL.LBR when a CPU is starting, prior to purging the
LBR MSRs themselves, as at least one system has been found to transfer
control to the kernel with LBRs enabled (it's unclear whether it's a BIOS
flaw or a CPU goof).  Because the kernel preserves the original DEBUGCTL,
even when toggling LBRs, leaving DEBUGCTL.LBR as is results in running
with LBRs enabled at all times.

Closes: https://lore.kernel.org/all/c9d8269bff69f6359731d758e3b1135dedd7cc61.camel@redhat.com
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250131010721.470503-1-seanjc@google.com
2025-02-08 15:47:26 +01:00
Kan Liang
47a973fd75 perf/x86/intel: Fix ARCH_PERFMON_NUM_COUNTER_LEAF
The EAX of the CPUID Leaf 023H enumerates the mask of valid sub-leaves.
To tell the availability of the sub-leaf 1 (enumerate the counter mask),
perf should check the bit 1 (0x2) of EAS, rather than bit 0 (0x1).

The error is not user-visible on bare metal. Because the sub-leaf 0 and
the sub-leaf 1 are always available. However, it may bring issues in a
virtualization environment when a VMM only enumerates the sub-leaf 0.

Introduce the cpuid35_e?x to replace the macros, which makes the
implementation style consistent.

Fixes: eb467aaac2 ("perf/x86/intel: Support Architectural PerfMon Extension leaf")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250129154820.3755948-3-kan.liang@linux.intel.com
2025-02-08 15:47:25 +01:00
Linus Torvalds
c545cd3276 Merge tag 'x86-mm-2025-01-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar:

 - The biggest changes are the TLB flushing scalability optimizations,
   to update the mm_cpumask lazily and related changes.

   This feature has both a track record and a continued risk of
   performance regressions, so it was already delayed by a cycle - but
   it's all 100% perfect now™ (Rik van Riel)

 - Also miscellaneous fixes and cleanups. (Gautam Somani, Kirill
   Shutemov, Sebastian Andrzej Siewior)

* tag 'x86-mm-2025-01-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Remove unnecessary include of <linux/extable.h>
  x86/mtrr: Rename mtrr_overwrite_state() to guest_force_mtrr_state()
  x86/mm/selftests: Fix typo in lam.c
  x86/mm/tlb: Only trim the mm_cpumask once a second
  x86/mm/tlb: Also remove local CPU from mm_cpumask if stale
  x86/mm/tlb: Add tracepoint for TLB flush IPI to stale CPU
  x86/mm/tlb: Update mm_cpumask lazily
2025-01-31 10:39:07 -08:00
Linus Torvalds
2a9f04bde0 Merge tag 'rtc-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
 "Not much this cycle, there are multiple small fixes.

  Core:
   - use boolean values with device_init_wakeup()

  Drivers:
   - pcf2127: add BSM support
   - pcf85063: fix possible out of bounds write"

* tag 'rtc-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: pcf2127: add BSM support
  rtc: Remove hpet_rtc_dropped_irq()
  dt-bindings: rtc: mxc: Document fsl,imx31-rtc
  rtc: stm32: Use syscon_regmap_lookup_by_phandle_args
  rtc: zynqmp: Fix optional clock name property
  rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc_isr()
  rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read
  rtc: tps6594: Fix integer overflow on 32bit systems
  rtc: use boolean values with device_init_wakeup()
  rtc: RTC_DRV_SPEAR should not default to y when compile-testing
2025-01-30 17:50:02 -08:00
Linus Torvalds
9c5968db9e Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...
2025-01-26 18:36:23 -08:00
Qi Zheng
e74e173101 mm: pgtable: move __tlb_remove_table_one() in x86 to generic file
The __tlb_remove_table_one() in x86 does not contain architecture-specific
content, so move it to the generic file.

Link: https://lkml.kernel.org/r/aab8a449bc67167943fd2cb5aab0a3a23b7b1cd7.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:23 -08:00
Qi Zheng
2dccdf7076 mm: pgtable: introduce generic __tlb_remove_table()
Several architectures (arm, arm64, riscv and x86) define exactly the same
__tlb_remove_table(), just introduce generic __tlb_remove_table() to
eliminate these duplications.

The s390 __tlb_remove_table() is nearly the same, so also make s390
__tlb_remove_table() version generic.

Link: https://lkml.kernel.org/r/ea372633d94f4d3f9f56a7ec5994bf050bf77e39.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>		[sparc]
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Acked-by: Arnd Bergmann <arnd@arndb.de>			[asm-generic]
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:23 -08:00
Qi Zheng
ee0934b035 x86: pgtable: move pagetable_dtor() to __tlb_remove_table()
Move pagetable_dtor() to __tlb_remove_table(), so that ptlock and page
table pages can be freed together (regardless of whether RCU is used). 
This prevents the use-after-free problem where the ptlock is freed
immediately but the page table pages is freed later via RCU.

Link: https://lkml.kernel.org/r/27b3cdc8786bebd4f748380bf82f796482718504.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:22 -08:00
Qi Zheng
0b6476f939 x86: pgtable: convert __tlb_remove_table() to use struct ptdesc
Convert __tlb_remove_table() to use struct ptdesc, which will help to move
pagetable_dtor() to __tlb_remove_table().

And page tables shouldn't have swap cache, so use pagetable_free() instead
of free_page_and_swap_cache() to free page table pages.

Link: https://lkml.kernel.org/r/39f60f93143ff77cf5d6b3c3e75af0ffc1480adb.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:22 -08:00
Kevin Brodsky
98a7e47faa asm-generic: pgalloc: provide generic p4d_{alloc_one,free}
Four architectures currently implement 5-level pgtables: arm64, riscv, x86
and s390.  The first three have essentially the same implementation for
p4d_alloc_one() and p4d_free(), so we've got an opportunity to reduce
duplication like at the lower levels.

Provide a generic version of p4d_alloc_one() and p4d_free(), and make use
of it on those architectures.

Their implementation is the same as at PUD level, except that p4d_free()
performs a runtime check by calling mm_p4d_folded().  5-level pgtables
depend on a runtime-detected hardware feature on all supported
architectures, so we might as well include this check in the generic
implementation.  No runtime check is required in p4d_alloc_one() as the
top-level p4d_alloc() already does the required check.

Link: https://lkml.kernel.org/r/26d69c74a29183ecc335b9b407040d8e4cd70c6a.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>		[asm-generic]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:21 -08:00
Linus Torvalds
0f8e26b38d Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "Loongarch:

   - Clear LLBCTL if secondary mmu mapping changes

   - Add hypercall service support for usermode VMM

  x86:

   - Add a comment to kvm_mmu_do_page_fault() to explain why KVM
     performs a direct call to kvm_tdp_page_fault() when RETPOLINE is
     enabled

   - Ensure that all SEV code is compiled out when disabled in Kconfig,
     even if building with less brilliant compilers

   - Remove a redundant TLB flush on AMD processors when guest CR4.PGE
     changes

   - Use str_enabled_disabled() to replace open coded strings

   - Drop kvm_x86_ops.hwapic_irr_update() as KVM updates hardware's
     APICv cache prior to every VM-Enter

   - Overhaul KVM's CPUID feature infrastructure to track all vCPU
     capabilities instead of just those where KVM needs to manage state
     and/or explicitly enable the feature in hardware. Along the way,
     refactor the code to make it easier to add features, and to make it
     more self-documenting how KVM is handling each feature

   - Rework KVM's handling of VM-Exits during event vectoring; this
     plugs holes where KVM unintentionally puts the vCPU into infinite
     loops in some scenarios (e.g. if emulation is triggered by the
     exit), and brings parity between VMX and SVM

   - Add pending request and interrupt injection information to the
     kvm_exit and kvm_entry tracepoints respectively

   - Fix a relatively benign flaw where KVM would end up redoing RDPKRU
     when loading guest/host PKRU, due to a refactoring of the kernel
     helpers that didn't account for KVM's pre-checking of the need to
     do WRPKRU

   - Make the completion of hypercalls go through the complete_hypercall
     function pointer argument, no matter if the hypercall exits to
     userspace or not.

     Previously, the code assumed that KVM_HC_MAP_GPA_RANGE specifically
     went to userspace, and all the others did not; the new code need
     not special case KVM_HC_MAP_GPA_RANGE and in fact does not care at
     all whether there was an exit to userspace or not

   - As part of enabling TDX virtual machines, support support
     separation of private/shared EPT into separate roots.

     When TDX will be enabled, operations on private pages will need to
     go through the privileged TDX Module via SEAMCALLs; as a result,
     they are limited and relatively slow compared to reading a PTE.

     The patches included in 6.14 allow KVM to keep a mirror of the
     private EPT in host memory, and define entries in kvm_x86_ops to
     operate on external page tables such as the TDX private EPT

   - The recently introduced conversion of the NX-page reclamation
     kthread to vhost_task moved the task under the main process. The
     task is created as soon as KVM_CREATE_VM was invoked and this, of
     course, broke userspace that didn't expect to see any child task of
     the VM process until it started creating its own userspace threads.

     In particular crosvm refuses to fork() if procfs shows any child
     task, so unbreak it by creating the task lazily. This is arguably a
     userspace bug, as there can be other kinds of legitimate worker
     tasks and they wouldn't impede fork(); but it's not like userspace
     has a way to distinguish kernel worker tasks right now. Should they
     show as "Kthread: 1" in proc/.../status?

  x86 - Intel:

   - Fix a bug where KVM updates hardware's APICv cache of the highest
     ISR bit while L2 is active, while ultimately results in a
     hardware-accelerated L1 EOI effectively being lost

   - Honor event priority when emulating Posted Interrupt delivery
     during nested VM-Enter by queueing KVM_REQ_EVENT instead of
     immediately handling the interrupt

   - Rework KVM's processing of the Page-Modification Logging buffer to
     reap entries in the same order they were created, i.e. to mark gfns
     dirty in the same order that hardware marked the page/PTE dirty

   - Misc cleanups

  Generic:

   - Cleanup and harden kvm_set_memory_region(); add proper lockdep
     assertions when setting memory regions and add a dedicated API for
     setting KVM-internal memory regions. The API can then explicitly
     disallow all flags for KVM-internal memory regions

   - Explicitly verify the target vCPU is online in kvm_get_vcpu() to
     fix a bug where KVM would return a pointer to a vCPU prior to it
     being fully online, and give kvm_for_each_vcpu() similar treatment
     to fix a similar flaw

   - Wait for a vCPU to come online prior to executing a vCPU ioctl, to
     fix a bug where userspace could coerce KVM into handling the ioctl
     on a vCPU that isn't yet onlined

   - Gracefully handle xarray insertion failures; even though such
     failures are impossible in practice after xa_reserve(), reserving
     an entry is always followed by xa_store() which does not know (or
     differentiate) whether there was an xa_reserve() before or not

  RISC-V:

   - Zabha, Svvptc, and Ziccrse extension support for guests. None of
     them require anything in KVM except for detecting them and marking
     them as supported; Zabha adds byte and halfword atomic operations,
     while the others are markers for specific operation of the TLB and
     of LL/SC instructions respectively

   - Virtualize SBI system suspend extension for Guest/VM

   - Support firmware counters which can be used by the guests to
     collect statistics about traps that occur in the host

  Selftests:

   - Rework vcpu_get_reg() to return a value instead of using an
     out-param, and update all affected arch code accordingly

   - Convert the max_guest_memory_test into a more generic
     mmu_stress_test. The basic gist of the "conversion" is to have the
     test do mprotect() on guest memory while vCPUs are accessing said
     memory, e.g. to verify KVM and mmu_notifiers are working as
     intended

   - Play nice with treewrite builds of unsupported architectures, e.g.
     arm (32-bit), as KVM selftests' Makefile doesn't do anything to
     ensure the target architecture is actually one KVM selftests
     supports

   - Use the kernel's $(ARCH) definition instead of the target triple
     for arch specific directories, e.g. arm64 instead of aarch64,
     mainly so as not to be different from the rest of the kernel

   - Ensure that format strings for logging statements are checked by
     the compiler even when the logging statement itself is disabled

   - Attempt to whack the last LLC references/misses mole in the Intel
     PMU counters test by adding a data load and doing CLFLUSH{OPT} on
     the data instead of the code being executed. It seems that modern
     Intel CPUs have learned new code prefetching tricks that bypass the
     PMU counters

   - Fix a flaw in the Intel PMU counters test where it asserts that
     events are counting correctly without actually knowing what the
     events count given the underlying hardware; this can happen if
     Intel reuses a formerly microarchitecture-specific event encoding
     as an architectural event, as was the case for Top-Down Slots"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (151 commits)
  kvm: defer huge page recovery vhost task to later
  KVM: x86/mmu: Return RET_PF* instead of 1 in kvm_mmu_page_fault()
  KVM: Disallow all flags for KVM-internal memslots
  KVM: x86: Drop double-underscores from __kvm_set_memory_region()
  KVM: Add a dedicated API for setting KVM-internal memslots
  KVM: Assert slots_lock is held when setting memory regions
  KVM: Open code kvm_set_memory_region() into its sole caller (ioctl() API)
  LoongArch: KVM: Add hypercall service support for usermode VMM
  LoongArch: KVM: Clear LLBCTL if secondary mmu mapping is changed
  KVM: SVM: Use str_enabled_disabled() helper in svm_hardware_setup()
  KVM: VMX: read the PML log in the same order as it was written
  KVM: VMX: refactor PML terminology
  KVM: VMX: Fix comment of handle_vmx_instruction()
  KVM: VMX: Reinstate __exit attribute for vmx_exit()
  KVM: SVM: Use str_enabled_disabled() helper in sev_hardware_setup()
  KVM: x86: Avoid double RDPKRU when loading host/guest PKRU
  KVM: x86: Use LVT_TIMER instead of an open coded literal
  RISC-V: KVM: Add new exit statstics for redirected traps
  RISC-V: KVM: Update firmware counters for various events
  RISC-V: KVM: Redirect instruction access fault trap to guest
  ...
2025-01-25 09:55:09 -08:00
Linus Torvalds
382e391365 Merge tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:

 - Introduce a new set of Hyper-V headers in include/hyperv and replace
   the old hyperv-tlfs.h with the new headers (Nuno Das Neves)

 - Fixes for the Hyper-V VTL mode (Roman Kisel)

 - Fixes for cpu mask usage in Hyper-V code (Michael Kelley)

 - Document the guest VM hibernation behaviour (Michael Kelley)

 - Miscellaneous fixes and cleanups (Jacob Pan, John Starks, Naman Jain)

* tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Documentation: hyperv: Add overview of guest VM hibernation
  hyperv: Do not overlap the hvcall IO areas in hv_vtl_apicid_to_vp_id()
  hyperv: Do not overlap the hvcall IO areas in get_vtl()
  hyperv: Enable the hypercall output page for the VTL mode
  hv_balloon: Fallback to generic_online_page() for non-HV hot added mem
  Drivers: hv: vmbus: Log on missing offers if any
  Drivers: hv: vmbus: Wait for boot-time offers during boot and resume
  uio_hv_generic: Add a check for HV_NIC for send, receive buffers setup
  iommu/hyper-v: Don't assume cpu_possible_mask is dense
  Drivers: hv: Don't assume cpu_possible_mask is dense
  x86/hyperv: Don't assume cpu_possible_mask is dense
  hyperv: Remove the now unused hyperv-tlfs.h files
  hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h
  hyperv: Add new Hyper-V headers in include/hyperv
  hyperv: Clean up unnecessary #includes
  hyperv: Move hv_connection_id to hyperv-tlfs.h
2025-01-25 09:22:55 -08:00
Linus Torvalds
ae8b53aac3 Merge tag 'efi-next-for-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel:

 - Increase the headroom in the EFI memory map allocation created by the
   EFI stub. This is needed because event callbacks called during
   ExitBootServices() may cause fragmentation, and reallocation is not
   allowed after that.

 - Drop obsolete UGA graphics code and switch to a more ergonomic API to
   traverse handle buffers. Simplify some error paths using a __free()
   helper while at it.

 - Fix some W=1 warnings when CONFIG_EFI=n

 - Rely on the dentry cache to keep track of the contents of the
   efivarfs filesystem, rather than using a separate linked list.

 - Improve and extend efivarfs test cases.

 - Synchronize efivarfs with underlying variable store on resume from
   hibernation - this is needed because the firmware itself or another
   OS running on the same machine may have modified it.

 - Fix x86 EFI stub build with GCC 15.

 - Fix kexec/x86 false positive warning in EFI memory attributes table
   sanity check.

* tag 'efi-next-for-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (23 commits)
  x86/efi: skip memattr table on kexec boot
  efivarfs: add variable resync after hibernation
  efivarfs: abstract initial variable creation routine
  efi: libstub: Use '-std=gnu11' to fix build with GCC 15
  selftests/efivarfs: add concurrent update tests
  selftests/efivarfs: fix tests for failed write removal
  efivarfs: fix error on write to new variable leaving remnants
  efivarfs: remove unused efivarfs_list
  efivarfs: move variable lifetime management into the inodes
  selftests/efivarfs: add check for disallowing file truncation
  efivarfs: prevent setting of zero size on the inodes in the cache
  efi: sysfb_efi: fix W=1 warnings when EFI is not set
  efi/libstub: Use __free() helper for pool deallocations
  efi/libstub: Use cleanup helpers for freeing copies of the memory map
  efi/libstub: Simplify PCI I/O handle buffer traversal
  efi/libstub: Refactor and clean up GOP resolution picker code
  efi/libstub: Simplify GOP handling code
  efi/libstub: Use C99-style for loop to traverse handle buffer
  x86/efistub: Drop long obsolete UGA support
  efivarfs: make variable_is_present use dcache lookup
  ...
2025-01-24 15:33:33 -08:00
Keith Busch
931656b9e2 kvm: defer huge page recovery vhost task to later
Some libraries want to ensure they are single threaded before forking,
so making the kernel's kvm huge page recovery process a vhost task of
the user process breaks those. The minijail library used by crosvm is
one such affected application.

Defer the task to after the first VM_RUN call, which occurs after the
parent process has forked all its jailed processes. This needs to happen
only once for the kvm instance, so introduce some general-purpose
infrastructure for that, too.  It's similar in concept to pthread_once;
except it is actually usable, because the callback takes a parameter.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Alyssa Ross <hi@alyssa.is>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Message-ID: <20250123153543.2769928-1-kbusch@meta.com>
[Move call_once API to include/linux. - Paolo]
Cc: stable@vger.kernel.org
Fixes: d96c77bd4e ("KVM: x86: switch hugepage recovery thread to vhost_task")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-01-24 10:53:56 -05:00
Linus Torvalds
c9c0543b52 Merge tag 'platform-drivers-x86-v6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver updates from Ilpo Järvinen:
 "acer-wmi:
   - Add support for PH14-51, PH16-72, and Nitro AN515-58
   - Add proper hwmon support
   - Improve error handling when reading "gaming system info"
   - Replace direct EC reads for the current platform profile with WMI
     calls to handle EC address variations
   - Replace custom platform_profile cycling with the generic one

  ACPI:
   - platform_profile: Major refactoring and improvements
   - Support registering multiple platform_profile handlers concurrently
     to avoid the need to quirk which handler takes precedence
   - Support reporting "custom" profile for cases where the current
     profile is ambiguous or when settings tweaks are done outside the
     pre-defined profile
   - Abstract and layer platform_profile API better using the class_dev
     and drvdata
   - Various minor improvements
   - Add Documentation and kerneldoc

  amd/hsmp:
   - Add support for HSMP protocol v7

  amd/pmc:
   - Support AMD 1Ah family 70h
   - Support STB with Ryzen desktop SoCs

  amd/pmf:
   - Support Custom BIOS inputs for PMF TA
   - Support passing SRA sensor data from AMD SFH (HID) to PMF TA

  dell-smo8800:
   - Move SMO88xx quirk away from the generic i2c-i801 driver
   - Add accelerometer support for Dell Latitude E6330/E6430 and XPS
     9550
   - Support probing accelerometer for models yet to be listed in the
     DMI mapping table because ACPI lacks i2c-address for the
     accelerometer (behind a module parameter because probing might be
     dangerous)

  HID:
   - amd_sfh: Add support for exporting SRA sensor data

  hp-wmi:
   - Add fan and thermal support for Victus 16-s1000

  input:
   - Add key for phone linking
   - i8042: Add context for the i8042 filter to enable cleaning up the
     filter related global variables from pdx86 drivers

  lenovo-wmi-camera:
   - Use SW_CAMERA_LENS_COVER instead of KEY_CAMERA_ACCESS

  mellanox mlxbf-pmc:
   - Add support for monitoring cycle count
   - Add Documentation

  thinkpad_acpi:
   - Add support for phone link key

  tools/power/x86/intel-speed-select:
   - Fix Turbo Ratio Limit restore

  x86-android-tables:
   - Add support for Vexia EDU ATLA 10 Bluetooth and EC battery driver

  And miscellaneous cleanups / refactoring / improvements"

* tag 'platform-drivers-x86-v6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (133 commits)
  platform/x86: acer-wmi: Fix initialization of last_non_turbo_profile
  platform/x86: acer-wmi: Ignore AC events
  platform/mellanox: mlxreg-io: use sysfs_emit() instead of sprintf()
  platform/mellanox: mlxreg-hotplug: use sysfs_emit() instead of sprintf()
  platform/mellanox: mlxbf-bootctl: use sysfs_emit() instead of sprintf()
  platform/x86: hp-wmi: Add fan and thermal profile support for Victus 16-s1000
  ACPI: platform_profile: Add a prefix to log messages
  ACPI: platform_profile: Add documentation
  ACPI: platform_profile: Clean platform_profile_handler
  ACPI: platform_profile: Move platform_profile_handler
  ACPI: platform_profile: Remove platform_profile_handler from exported symbols
  platform/x86: thinkpad_acpi: Use devm_platform_profile_register()
  platform/x86: inspur_platform_profile: Use devm_platform_profile_register()
  platform/x86: hp-wmi: Use devm_platform_profile_register()
  platform/x86: ideapad-laptop: Use devm_platform_profile_register()
  platform/x86: dell-pc: Use devm_platform_profile_register()
  platform/x86: asus-wmi: Use devm_platform_profile_register()
  platform/x86: amd: pmf: sps: Use devm_platform_profile_register()
  platform/x86: acer-wmi: Use devm_platform_profile_register()
  platform/surface: surface_platform_profile: Use devm_platform_profile_register()
  ...
2025-01-24 07:18:39 -08:00
Linus Torvalds
113691ce9f Merge tag 'x86_tdx_for_6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 TDX updates from Dave Hansen:
 "Intel Trust Domain updates.

  The existing TDX code needs a _bit_ of metadata from the TDX module.
  But KVM is going to need a bunch more very shortly. Rework the
  interface with the TDX module to be more consistent and handle the new
  higher volume.

  The TDX module has added a few new features. The first is a promise
  not to clobber RBP under any circumstances. Basically the kernel now
  will refuse to use any modules that don't have this promise. Second,
  enable the new "REDUCE_VE" feature. This ensures that the TDX module
  will not send some silly virtualization exceptions that the guest had
  no good way to handle anyway.

   - Centralize global metadata infrastructure

   - Use new TDX module features for exception suppression and RBP
     clobbering"

* tag 'x86_tdx_for_6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/virt/tdx: Require the module to assert it has the NO_RBP_MOD mitigation
  x86/virt/tdx: Switch to use auto-generated global metadata reading code
  x86/virt/tdx: Use dedicated struct members for PAMT entry sizes
  x86/virt/tdx: Use auto-generated code to read global metadata
  x86/virt/tdx: Start to track all global metadata in one structure
  x86/virt/tdx: Rename 'struct tdx_tdmr_sysinfo' to reflect the spec better
  x86/tdx: Dump attributes and TD_CTLS on boot
  x86/tdx: Disable unnecessary virtualization exceptions
2025-01-24 05:58:31 -08:00
Linus Torvalds
5b7f7234ff Merge tag 'x86-boot-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar:

 - A large and involved preparatory series to pave the way to add
   exception handling for relocate_kernel - which will be a debugging
   facility that has aided in the field to debug an exceptionally hard
   to debug early boot bug. Plus assorted cleanups and fixes that were
   discovered along the way, by David Woodhouse:

      - Clean up and document register use in relocate_kernel_64.S
      - Use named labels in swap_pages in relocate_kernel_64.S
      - Only swap pages for ::preserve_context mode
      - Allocate PGD for x86_64 transition page tables separately
      - Copy control page into place in machine_kexec_prepare()
      - Invoke copy of relocate_kernel() instead of the original
      - Move relocate_kernel to kernel .data section
      - Add data section to relocate_kernel
      - Drop page_list argument from relocate_kernel()
      - Eliminate writes through kernel mapping of relocate_kernel page
      - Clean up register usage in relocate_kernel()
      - Mark relocate_kernel page as ROX instead of RWX
      - Disable global pages before writing to control page
      - Ensure preserve_context flag is set on return to kernel
      - Use correct swap page in swap_pages function
      - Fix stack and handling of re-entry point for ::preserve_context
      - Mark machine_kexec() with __nocfi
      - Cope with relocate_kernel() not being at the start of the page
      - Use typedef for relocate_kernel_fn function prototype
      - Fix location of relocate_kernel with -ffunction-sections (fix by Nathan Chancellor)

 - A series to remove the last remaining absolute symbol references from
   .head.text, and enforce this at build time, by Ard Biesheuvel:

      - Avoid WARN()s and panic()s in early boot code
      - Don't hang but terminate on failure to remap SVSM CA
      - Determine VA/PA offset before entering C code
      - Avoid intentional absolute symbol references in .head.text
      - Disable UBSAN in early boot code
      - Move ENTRY_TEXT to the start of the image
      - Move .head.text into its own output section
      - Reject absolute references in .head.text

 - The above build-time enforcement uncovered a handful of bugs of
   essentially non-working code, and a wrokaround for a toolchain bug,
   fixed by Ard Biesheuvel as well:

      - Fix spurious undefined reference when CONFIG_X86_5LEVEL=n, on GCC-12
      - Disable UBSAN on SEV code that may execute very early
      - Disable ftrace branch profiling in SEV startup code

 - And miscellaneous cleanups:

      - kexec_core: Add and update comments regarding the KEXEC_JUMP flow (Rafael J. Wysocki)
      - x86/sysfs: Constify 'struct bin_attribute' (Thomas Weißschuh)"

* tag 'x86-boot-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  x86/sev: Disable ftrace branch profiling in SEV startup code
  x86/kexec: Use typedef for relocate_kernel_fn function prototype
  x86/kexec: Cope with relocate_kernel() not being at the start of the page
  kexec_core: Add and update comments regarding the KEXEC_JUMP flow
  x86/kexec: Mark machine_kexec() with __nocfi
  x86/kexec: Fix location of relocate_kernel with -ffunction-sections
  x86/kexec: Fix stack and handling of re-entry point for ::preserve_context
  x86/kexec: Use correct swap page in swap_pages function
  x86/kexec: Ensure preserve_context flag is set on return to kernel
  x86/kexec: Disable global pages before writing to control page
  x86/sev: Don't hang but terminate on failure to remap SVSM CA
  x86/sev: Disable UBSAN on SEV code that may execute very early
  x86/boot/64: Fix spurious undefined reference when CONFIG_X86_5LEVEL=n, on GCC-12
  x86/sysfs: Constify 'struct bin_attribute'
  x86/kexec: Mark relocate_kernel page as ROX instead of RWX
  x86/kexec: Clean up register usage in relocate_kernel()
  x86/kexec: Eliminate writes through kernel mapping of relocate_kernel page
  x86/kexec: Drop page_list argument from relocate_kernel()
  x86/kexec: Add data section to relocate_kernel
  x86/kexec: Move relocate_kernel to kernel .data section
  ...
2025-01-24 05:54:26 -08:00
Linus Torvalds
2e04247f7c Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:

 - Have fprobes built on top of function graph infrastructure

   The fprobe logic is an optimized kprobe that uses ftrace to attach to
   functions when a probe is needed at the start or end of the function.
   The fprobe and kretprobe logic implements a similar method as the
   function graph tracer to trace the end of the function. That is to
   hijack the return address and jump to a trampoline to do the trace
   when the function exits. To do this, a shadow stack needs to be
   created to store the original return address. Fprobes and function
   graph do this slightly differently. Fprobes (and kretprobes) has
   slots per callsite that are reserved to save the return address. This
   is fine when just a few points are traced. But users of fprobes, such
   as BPF programs, are starting to add many more locations, and this
   method does not scale.

   The function graph tracer was created to trace all functions in the
   kernel. In order to do this, when function graph tracing is started,
   every task gets its own shadow stack to hold the return address that
   is going to be traced. The function graph tracer has been updated to
   allow multiple users to use its infrastructure. Now have fprobes be
   one of those users. This will also allow for the fprobe and kretprobe
   methods to trace the return address to become obsolete. With new
   technologies like CFI that need to know about these methods of
   hijacking the return address, going toward a solution that has only
   one method of doing this will make the kernel less complex.

 - Cleanup with guard() and free() helpers

   There were several places in the code that had a lot of "goto out" in
   the error paths to either unlock a lock or free some memory that was
   allocated. But this is error prone. Convert the code over to use the
   guard() and free() helpers that let the compiler unlock locks or free
   memory when the function exits.

 - Remove disabling of interrupts in the function graph tracer

   When function graph tracer was first introduced, it could race with
   interrupts and NMIs. To prevent that race, it would disable
   interrupts and not trace NMIs. But the code has changed to allow NMIs
   and also interrupts. This change was done a long time ago, but the
   disabling of interrupts was never removed. Remove the disabling of
   interrupts in the function graph tracer is it is not needed. This
   greatly improves its performance.

 - Allow the :mod: command to enable tracing module functions on the
   kernel command line.

   The function tracer already has a way to enable functions to be
   traced in modules by writing ":mod:<module>" into set_ftrace_filter.
   That will enable either all the functions for the module if it is
   loaded, or if it is not, it will cache that command, and when the
   module is loaded that matches <module>, its functions will be
   enabled. This also allows init functions to be traced. But currently
   events do not have that feature.

   Because enabling function tracing can be done very early at boot up
   (before scheduling is enabled), the commands that can be done when
   function tracing is started is limited. Having the ":mod:" command to
   trace module functions as they are loaded is very useful. Update the
   kernel command line function filtering to allow it.

* tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
  ftrace: Implement :mod: cache filtering on kernel command line
  tracing: Adopt __free() and guard() for trace_fprobe.c
  bpf: Use ftrace_get_symaddr() for kprobe_multi probes
  ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr
  Documentation: probes: Update fprobe on function-graph tracer
  selftests/ftrace: Add a test case for repeating register/unregister fprobe
  selftests: ftrace: Remove obsolate maxactive syntax check
  tracing/fprobe: Remove nr_maxactive from fprobe
  fprobe: Add fprobe_header encoding feature
  fprobe: Rewrite fprobe on function-graph tracer
  s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC
  ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC
  bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
  tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
  tracing: Add ftrace_fill_perf_regs() for perf event
  tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
  fprobe: Use ftrace_regs in fprobe exit handler
  fprobe: Use ftrace_regs in fprobe entry handler
  fgraph: Pass ftrace_regs to retfunc
  fgraph: Replace fgraph_ret_regs with ftrace_regs
  ...
2025-01-21 15:15:28 -08:00
Linus Torvalds
62de6e1685 Merge tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "Fair scheduler (SCHED_FAIR) enhancements:

   - Behavioral improvements:
      - Untangle NEXT_BUDDY and pick_next_task() (Peter Zijlstra)

   - Delayed-dequeue enhancements & fixes: (Vincent Guittot)
      - Rename h_nr_running into h_nr_queued
      - Add new cfs_rq.h_nr_runnable
      - Use the new cfs_rq.h_nr_runnable
      - Removed unsued cfs_rq.h_nr_delayed
      - Rename cfs_rq.idle_h_nr_running into h_nr_idle
      - Remove unused cfs_rq.idle_nr_running
      - Rename cfs_rq.nr_running into nr_queued
      - Do not try to migrate delayed dequeue task
      - Fix variable declaration position
      - Encapsulate set custom slice in a __setparam_fair() function

   - Fixes:
      - Fix race between yield_to() and try_to_wake_up() (Tianchen Ding)
      - Fix CPU bandwidth limit bypass during CPU hotplug (Vishal
        Chourasia)

   - Cleanups:
      - Clean up in migrate_degrades_locality() to improve readability
        (Peter Zijlstra)
      - Mark m*_vruntime() with __maybe_unused (Andy Shevchenko)
      - Update comments after sched_tick() rename (Sebastian Andrzej
        Siewior)
      - Remove CONFIG_CFS_BANDWIDTH=n definition of cfs_bandwidth_used()
        (Valentin Schneider)

  Deadline scheduler (SCHED_DL) enhancements:

   - Restore dl_server bandwidth on non-destructive root domain changes
     (Juri Lelli)

   - Correctly account for allocated bandwidth during hotplug (Juri
     Lelli)

   - Check bandwidth overflow earlier for hotplug (Juri Lelli)

   - Clean up goto label in pick_earliest_pushable_dl_task() (John
     Stultz)

   - Consolidate timer cancellation (Wander Lairson Costa)

  Load-balancer enhancements:

   - Improve performance by prioritizing migrating eligible tasks in
     sched_balance_rq() (Hao Jia)

   - Do not compute NUMA Balancing stats unnecessarily during
     load-balancing (K Prateek Nayak)

   - Do not compute overloaded status unnecessarily during
     load-balancing (K Prateek Nayak)

  Generic scheduling code enhancements:

   - Use READ_ONCE() in task_on_rq_queued(), to consistently use the
     WRITE_ONCE() updated ->on_rq field (Harshit Agarwal)

  Isolated CPUs support enhancements: (Waiman Long)

   - Make "isolcpus=nohz" equivalent to "nohz_full"
   - Consolidate housekeeping cpumasks that are always identical
   - Remove HK_TYPE_SCHED
   - Unify HK_TYPE_{TIMER|TICK|MISC} to HK_TYPE_KERNEL_NOISE

  RSEQ enhancements:

   - Validate read-only fields under DEBUG_RSEQ config (Mathieu
     Desnoyers)

  PSI enhancements:

   - Fix race when task wakes up before psi_sched_switch() adjusts flags
     (Chengming Zhou)

  IRQ time accounting performance enhancements: (Yafang Shao)

   - Define sched_clock_irqtime as static key
   - Don't account irq time if sched_clock_irqtime is disabled

  Virtual machine scheduling enhancements:

   - Don't try to catch up excess steal time (Suleiman Souhlal)

  Heterogenous x86 CPU scheduling enhancements: (K Prateek Nayak)

   - Convert "sysctl_sched_itmt_enabled" to boolean
   - Use guard() for itmt_update_mutex
   - Move the "sched_itmt_enabled" sysctl to debugfs
   - Remove x86_smt_flags and use cpu_smt_flags directly
   - Use x86_sched_itmt_flags for PKG domain unconditionally

  Debugging code & instrumentation enhancements:

   - Change need_resched warnings to pr_err() (David Rientjes)
   - Print domain name in /proc/schedstat (K Prateek Nayak)
   - Fix value reported by hot tasks pulled in /proc/schedstat (Peter
     Zijlstra)
   - Report the different kinds of imbalances in /proc/schedstat
     (Swapnil Sapkal)
   - Move sched domain name out of CONFIG_SCHED_DEBUG (Swapnil Sapkal)
   - Update Schedstat version to 17 (Swapnil Sapkal)"

* tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  rseq: Fix rseq unregistration regression
  psi: Fix race when task wakes up before psi_sched_switch() adjusts flags
  sched, psi: Don't account irq time if sched_clock_irqtime is disabled
  sched: Don't account irq time if sched_clock_irqtime is disabled
  sched: Define sched_clock_irqtime as static key
  sched/fair: Do not compute overloaded status unnecessarily during lb
  sched/fair: Do not compute NUMA Balancing stats unnecessarily during lb
  x86/topology: Use x86_sched_itmt_flags for PKG domain unconditionally
  x86/topology: Remove x86_smt_flags and use cpu_smt_flags directly
  x86/itmt: Move the "sched_itmt_enabled" sysctl to debugfs
  x86/itmt: Use guard() for itmt_update_mutex
  x86/itmt: Convert "sysctl_sched_itmt_enabled" to boolean
  sched/core: Prioritize migrating eligible tasks in sched_balance_rq()
  sched/debug: Change need_resched warnings to pr_err
  sched/fair: Encapsulate set custom slice in a __setparam_fair() function
  sched: Fix race between yield_to() and try_to_wake_up()
  docs: Update Schedstat version to 17
  sched/stats: Print domain name in /proc/schedstat
  sched: Move sched domain name out of CONFIG_SCHED_DEBUG
  sched: Report the different kinds of imbalances in /proc/schedstat
  ...
2025-01-21 11:32:36 -08:00
Linus Torvalds
858df1de21 Merge tag 'x86-cleanups-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
 "Miscellaneous x86 cleanups and typo fixes, and also the removal of
  the 'disablelapic' boot parameter"

* tag 'x86-cleanups-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioapic: Remove a stray tab in the IO-APIC type string
  x86/cpufeatures: Remove "AMD" from the comments to the AMD-specific leaf
  Documentation/kernel-parameters: Fix a typo in kvm.enable_virt_at_load text
  x86/cpu: Fix typo in x86_match_cpu()'s doc
  x86/apic: Remove "disablelapic" cmdline option
  Documentation: Merge x86-specific boot options doc into kernel-parameters.txt
  x86/ioremap: Remove unused size parameter in remapping functions
  x86/ioremap: Simplify setup_data mapping variants
  x86/boot/compressed: Remove unused header includes from kaslr.c
2025-01-21 11:15:29 -08:00
Linus Torvalds
6c4aa896eb Merge tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
 "Seqlock optimizations that arose in a perf context and were merged
  into the perf tree:

   - seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
   - mm: Convert mm_lock_seq to a proper seqcount (Suren Baghdasaryan)
   - mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren
     Baghdasaryan)
   - mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)

  Core perf enhancements:

   - Reduce 'struct page' footprint of perf by mapping pages in advance
     (Lorenzo Stoakes)
   - Save raw sample data conditionally based on sample type (Yabin Cui)
   - Reduce sampling overhead by checking sample_type in
     perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin
     Cui)
   - Export perf_exclude_event() (Namhyung Kim)

  Uprobes scalability enhancements: (Andrii Nakryiko)

   - Simplify find_active_uprobe_rcu() VMA checks
   - Add speculative lockless VMA-to-inode-to-uprobe resolution
   - Simplify session consumer tracking
   - Decouple return_instance list traversal and freeing
   - Ensure return_instance is detached from the list before freeing
   - Reuse return_instances between multiple uretprobes within task
   - Guard against kmemdup() failing in dup_return_instance()

  AMD core PMU driver enhancements:

   - Relax privilege filter restriction on AMD IBS (Namhyung Kim)

  AMD RAPL energy counters support: (Dhananjay Ugwekar)

   - Introduce topology_logical_core_id() (K Prateek Nayak)
   - Remove the unused get_rapl_pmu_cpumask() function
   - Remove the cpu_to_rapl_pmu() function
   - Rename rapl_pmu variables
   - Make rapl_model struct global
   - Add arguments to the init and cleanup functions
   - Modify the generic variable names to *_pkg*
   - Remove the global variable rapl_msrs
   - Move the cntr_mask to rapl_pmus struct
   - Add core energy counter support for AMD CPUs

  Intel core PMU driver enhancements:

   - Support RDPMC 'metrics clear mode' feature (Kan Liang)
   - Clarify adaptive PEBS processing (Kan Liang)
   - Factor out functions for PEBS records processing (Kan Liang)
   - Simplify the PEBS records processing for adaptive PEBS (Kan Liang)

  Intel uncore driver enhancements: (Kan Liang)

   - Convert buggy pmu->func_id use to pmu->registered
   - Support more units on Granite Rapids"

* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  perf: map pages in advance
  perf/x86/intel/uncore: Support more units on Granite Rapids
  perf/x86/intel/uncore: Clean up func_id
  perf/x86/intel: Support RDPMC metrics clear mode
  uprobes: Guard against kmemdup() failing in dup_return_instance()
  perf/x86: Relax privilege filter restriction on AMD IBS
  perf/core: Export perf_exclude_event()
  uprobes: Reuse return_instances between multiple uretprobes within task
  uprobes: Ensure return_instance is detached from the list before freeing
  uprobes: Decouple return_instance list traversal and freeing
  uprobes: Simplify session consumer tracking
  uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
  uprobes: simplify find_active_uprobe_rcu() VMA checks
  mm: introduce mmap_lock_speculate_{try_begin|retry}
  mm: convert mm_lock_seq to a proper seqcount
  mm/gup: Use raw_seqcount_try_begin()
  seqlock: add raw_seqcount_try_begin
  perf/x86/rapl: Add core energy counter support for AMD CPUs
  perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
  perf/x86/rapl: Remove the global variable rapl_msrs
  ...
2025-01-21 10:52:03 -08:00
Linus Torvalds
a6640c8c2f Merge tag 'objtool-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:

 - Introduce the generic section-based annotation infrastructure a.k.a.
   ASM_ANNOTATE/ANNOTATE (Peter Zijlstra)

 - Convert various facilities to ASM_ANNOTATE/ANNOTATE: (Peter Zijlstra)
    - ANNOTATE_NOENDBR
    - ANNOTATE_RETPOLINE_SAFE
    - instrumentation_{begin,end}()
    - VALIDATE_UNRET_BEGIN
    - ANNOTATE_IGNORE_ALTERNATIVE
    - ANNOTATE_INTRA_FUNCTION_CALL
    - {.UN}REACHABLE

 - Optimize the annotation-sections parsing code (Peter Zijlstra)

 - Centralize annotation definitions in <linux/objtool.h>

 - Unify & simplify the barrier_before_unreachable()/unreachable()
   definitions (Peter Zijlstra)

 - Convert unreachable() calls to BUG() in x86 code, as unreachable()
   has unreliable code generation (Peter Zijlstra)

 - Remove annotate_reachable() and annotate_unreachable(), as it's
   unreliable against compiler optimizations (Peter Zijlstra)

 - Fix non-standard ANNOTATE_REACHABLE annotation order (Peter Zijlstra)

 - Robustify the annotation code by warning about unknown annotation
   types (Peter Zijlstra)

 - Allow arch code to discover jump table size, in preparation of
   annotated jump table support (Ard Biesheuvel)

* tag 'objtool-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Convert unreachable() to BUG()
  objtool: Allow arch code to discover jump table size
  objtool: Warn about unknown annotation types
  objtool: Fix ANNOTATE_REACHABLE to be a normal annotation
  objtool: Convert {.UN}REACHABLE to ANNOTATE
  objtool: Remove annotate_{,un}reachable()
  loongarch: Use ASM_REACHABLE
  x86: Convert unreachable() to BUG()
  unreachable: Unify
  objtool: Collect more annotations in objtool.h
  objtool: Collapse annotate sequences
  objtool: Convert ANNOTATE_INTRA_FUNCTION_CALL to ANNOTATE
  objtool: Convert ANNOTATE_IGNORE_ALTERNATIVE to ANNOTATE
  objtool: Convert VALIDATE_UNRET_BEGIN to ANNOTATE
  objtool: Convert instrumentation_{begin,end}() to ANNOTATE
  objtool: Convert ANNOTATE_RETPOLINE_SAFE to ANNOTATE
  objtool: Convert ANNOTATE_NOENDBR to ANNOTATE
  objtool: Generic annotation infrastructure
2025-01-21 10:13:11 -08:00
Linus Torvalds
b9d8a295ed Merge tag 'x86_misc_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov:

 - The first part of a restructuring of AMD's representation of a
   northbridge which is legacy now, and the creation of the new AMD node
   concept which represents the Zen architecture of having a collection
   of I/O devices within an SoC. Those nodes comprise the so-called data
   fabric on Zen.

   This has at least one practical advantage of not having to add a PCI
   ID each time a new data fabric PCI device releases. Eventually, the
   lot more uniform provider of data fabric functionality amd_node.c
   will be used by all the drivers which need it

 - Smaller cleanups

* tag 'x86_misc_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/amd_node: Use defines for SMN register offsets
  x86/amd_node: Remove dependency on AMD_NB
  x86/amd_node: Update __amd_smn_rw() error paths
  x86/amd_nb: Move SMN access code to a new amd_node driver
  x86/amd_nb, hwmon: (k10temp): Simplify amd_pci_dev_to_node_id()
  x86/amd_nb: Simplify function 3 search
  x86/amd_nb: Use topology info to get AMD node count
  x86/amd_nb: Simplify root device search
  x86/amd_nb: Simplify function 4 search
  x86: Start moving AMD node functionality out of AMD_NB
  x86/amd_nb: Clean up early_is_amd_nb()
  x86/amd_nb: Restrict init function to AMD-based systems
  x86/mtrr: Rename mtrr_overwrite_state() to guest_force_mtrr_state()
2025-01-21 09:38:52 -08:00
Linus Torvalds
48795f90cb Merge tag 'x86_cpu_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Borislav Petkov:

 - Remove the less generic CPU matching infra around struct x86_cpu_desc
   and use the generic struct x86_cpu_id thing

 - Remove magic naked numbers for CPUID functions and use proper defines
   of the prefix CPUID_LEAF_*. Consolidate some of the crazy use around
   the tree

 - Smaller cleanups and improvements

* tag 'x86_cpu_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Make all all CPUID leaf names consistent
  x86/fpu: Remove unnecessary CPUID level check
  x86/fpu: Move CPUID leaf definitions to common code
  x86/tsc: Remove CPUID "frequency" leaf magic numbers.
  x86/tsc: Move away from TSC leaf magic numbers
  x86/cpu: Move TSC CPUID leaf definition
  x86/cpu: Refresh DCA leaf reading code
  x86/cpu: Remove unnecessary MwAIT leaf checks
  x86/cpu: Use MWAIT leaf definition
  x86/cpu: Move MWAIT leaf definition to common header
  x86/cpu: Remove 'x86_cpu_desc' infrastructure
  x86/cpu: Move AMD erratum 1386 table over to 'x86_cpu_id'
  x86/cpu: Replace PEBS use of 'x86_cpu_desc' use with 'x86_cpu_id'
  x86/cpu: Expose only stepping min/max interface
  x86/cpu: Introduce new microcode matching helper
  x86/cpufeature: Document cpu_feature_enabled() as the default to use
  x86/paravirt: Remove the WBINVD callback
  x86/cpufeatures: Free up unused feature bits
2025-01-21 09:30:59 -08:00
Linus Torvalds
13b6931c44 Merge tag 'x86_sev_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov:

 - A segmented Reverse Map table (RMP) is a across-nodes distributed
   table of sorts which contains per-node descriptors of each node-local
   4K page, denoting its ownership (hypervisor, guest, etc) in the realm
   of confidential computing. Add support for such a table in order to
   improve referential locality when accessing or modifying RMP table
   entries

 - Add support for reading the TSC in SNP guests by removing any
   interference or influence the hypervisor might have, with the goal of
   making a confidential guest even more independent from the hypervisor

* tag 'x86_sev_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev: Add the Secure TSC feature for SNP guests
  x86/tsc: Init the TSC for Secure TSC guests
  x86/sev: Mark the TSC in a secure TSC guest as reliable
  x86/sev: Prevent RDTSC/RDTSCP interception for Secure TSC enabled guests
  x86/sev: Prevent GUEST_TSC_FREQ MSR interception for Secure TSC enabled guests
  x86/sev: Change TSC MSR behavior for Secure TSC enabled guests
  x86/sev: Add Secure TSC support for SNP guests
  x86/sev: Relocate SNP guest messaging routines to common code
  x86/sev: Carve out and export SNP guest messaging init routines
  virt: sev-guest: Replace GFP_KERNEL_ACCOUNT with GFP_KERNEL
  virt: sev-guest: Remove is_vmpck_empty() helper
  x86/sev/docs: Document the SNP Reverse Map Table (RMP)
  x86/sev: Add full support for a segmented RMP table
  x86/sev: Treat the contiguous RMP table as a single RMP segment
  x86/sev: Map only the RMP table entries instead of the full RMP range
  x86/sev: Move the SNP probe routine out of the way
  x86/sev: Require the RMPREAD instruction after Zen4
  x86/sev: Add support for the RMPREAD instruction
  x86/sev: Prepare for using the RMPREAD instruction to access the RMP
2025-01-21 09:00:31 -08:00
Linus Torvalds
d80825ee4a Merge tag 'x86_bugs_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 CPU speculation update from Borislav Petkov:

 - Add support for AMD hardware which is not affected by SRSO on the
   user/kernel attack vector and advertise it to guest userspace

* tag 'x86_bugs_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: x86: Advertise SRSO_USER_KERNEL_NO to userspace
  x86/bugs: Add SRSO_USER_KERNEL_NO support
2025-01-21 08:22:40 -08:00
Linus Torvalds
d3504411a4 Merge tag 'ras_core_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS updates from Borislav Petkov:

 - Remove the shared threshold bank hack on AMD and streamline and
   simplify it

 - Cleanup and sanitize MCA code

* tag 'ras_core_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce/amd: Remove shared threshold bank plumbing
  x86/mce: Remove the redundant mce_hygon_feature_init()
  x86/mce: Convert family/model mixed checks to VFM-based checks
  x86/mce: Break up __mcheck_cpu_apply_quirks()
  x86/mce: Make four functions return bool
  x86/mce/threshold: Remove the redundant this_cpu_dec_return()
  x86/mce: Make several functions return bool
2025-01-21 08:16:24 -08:00
Linus Torvalds
91309a7082 x86: use cmov for user address masking
This was a suggestion by David Laight, and while I was slightly worried
that some micro-architecture would predict cmov like a conditional
branch, there is little reason to actually believe any core would be
that broken.

Intel documents that their existing cores treat CMOVcc as a data
dependency that will constrain speculation in their "Speculative
Execution Side Channel Mitigations" whitepaper:

  "Other instructions such as CMOVcc, AND, ADC, SBB and SETcc can also
   be used to prevent bounds check bypass by constraining speculative
   execution on current family 6 processors (Intel® Core™, Intel® Atom™,
   Intel® Xeon® and Intel® Xeon Phi™ processors)"

and while that leaves the future uarch issues open, that's certainly
true of our traditional SBB usage too.

Any core that predicts CMOV will be unusable for various crypto
algorithms that need data-independent timing stability, so let's just
treat CMOV as the safe choice that simplifies the address masking by
avoiding an extra instruction and doesn't need a temporary register.

Suggested-by: David Laight <David.Laight@aculab.com>
Link: https://www.intel.com/content/dam/develop/external/us/en/documents/336996-speculative-execution-side-channel-mitigations.pdf
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-01-20 08:51:44 -08:00
Linus Torvalds
027ea4f5f2 x86: use proper 'clac' and 'stac' opcode names
Back when we added SMAP support, all versions of binutils didn't
necessarily understand the 'clac' and 'stac' instructions.  So we
implemented those instructions manually as ".byte" sequences.

But we've since upgraded the minimum version of binutils to version
2.25, and that included proper support for the SMAP instructions, and
there's no reason for us to use some line noise to express them any
more.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-01-20 08:39:29 -08:00
Paolo Bonzini
86eb1aef72 Merge branch 'kvm-mirror-page-tables' into HEAD
As part of enabling TDX virtual machines, support support separation of
private/shared EPT into separate roots.

Confidential computing solutions almost invariably have concepts of
private and shared memory, but they may different a lot in the details.
In SEV, for example, the bit is handled more like a permission bit as
far as the page tables are concerned: the private/shared bit is not
included in the physical address.

For TDX, instead, the bit is more like a physical address bit, with
the host mapping private memory in one half of the address space and
shared in another.  Furthermore, the two halves are mapped by different
EPT roots and only the shared half is managed by KVM; the private half
(also called Secure EPT in Intel documentation) gets managed by the
privileged TDX Module via SEAMCALLs.

As a result, the operations that actually change the private half of
the EPT are limited and relatively slow compared to reading a PTE. For
this reason the design for KVM is to keep a mirror of the private EPT in
host memory.  This allows KVM to quickly walk the EPT and only perform the
slower private EPT operations when it needs to actually modify mid-level
private PTEs.

There are thus three sets of EPT page tables: external, mirror and
direct.  In the case of TDX (the only user of this framework) the
first two cover private memory, whereas the third manages shared
memory:

  external EPT - Hidden within the TDX module, modified via TDX module
                 calls.

  mirror EPT   - Bookkeeping tree used as an optimization by KVM, not
                 used by the processor.

  direct EPT   - Normal EPT that maps unencrypted shared memory.
                 Managed like the EPT of a normal VM.

Modifying external EPT
----------------------

Modifications to the mirrored page tables need to also perform the
same operations to the private page tables, which will be handled via
kvm_x86_ops.  Although this prep series does not interact with the TDX
module at all to actually configure the private EPT, it does lay the
ground work for doing this.

In some ways updating the private EPT is as simple as plumbing PTE
modifications through to also call into the TDX module; however, the
locking is more complicated because inserting a single PTE cannot anymore
be done atomically with a single CMPXCHG.  For this reason, the existing
FROZEN_SPTE mechanism is used whenever a call to the TDX module updates the
private EPT.  FROZEN_SPTE acts basically as a spinlock on a PTE.  Besides
protecting operation of KVM, it limits the set of cases in which the
TDX module will encounter contention on its own PTE locks.

Zapping external EPT
--------------------
While the framework tries to be relatively generic, and to be
understandable without knowing TDX much in detail, some requirements of
TDX sometimes leak; for example the private page tables also cannot be
zapped while the range has anything mapped, so the mirrored/private page
tables need to be protected from KVM operations that zap any non-leaf
PTEs, for example kvm_mmu_reset_context() or kvm_mmu_zap_all_fast().

For normal VMs, guest memory is zapped for several reasons: user
memory getting paged out by the guest, memslots getting deleted,
passthrough of devices with non-coherent DMA.  Confidential computing
adds to these the conversion of memory between shared and privates. These
operations must not zap any private memory that is in use by the guest.

This is possible because the only zapping that is out of the control
of KVM/userspace is paging out userspace memory, which cannot apply to
guestmemfd operations.  Thus a TDX VM will only zap private memory from
memslot deletion and from conversion between private and shared memory
which is triggered by the guest.

To avoid zapping too much memory, enums are introduced so that operations
can choose to target only private or shared memory, and thus only
direct or mirror EPT.  For example:

  Memslot deletion           - Private and shared
  MMU notifier based zapping - Shared only
  Conversion to shared       - Private only
  Conversion to private      - Shared only

Other cases of zapping will not be supported for KVM, for example
APICv update or non-coherent DMA status update; for the latter, TDX will
simply require that the CPU supports self-snoop and honor guest PAT
unconditionally for shared memory.
2025-01-20 07:15:58 -05:00
Paolo Bonzini
3eba032bb7 Merge branch 'kvm-userspace-hypercall' into HEAD
Make the completion of hypercalls go through the complete_hypercall
function pointer argument, no matter if the hypercall exits to
userspace or not.  Previously, the code assumed that KVM_HC_MAP_GPA_RANGE
specifically went to userspace, and all the others did not; the new code
need not special case KVM_HC_MAP_GPA_RANGE and in fact does not care at
all whether there was an exit to userspace or not.
2025-01-20 07:03:06 -05:00
Paolo Bonzini
4f7ff70c05 Merge tag 'kvm-x86-misc-6.14' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.14:

 - Overhaul KVM's CPUID feature infrastructure to track all vCPU capabilities
   instead of just those where KVM needs to manage state and/or explicitly
   enable the feature in hardware.  Along the way, refactor the code to make
   it easier to add features, and to make it more self-documenting how KVM
   is handling each feature.

 - Rework KVM's handling of VM-Exits during event vectoring; this plugs holes
   where KVM unintentionally puts the vCPU into infinite loops in some scenarios
   (e.g. if emulation is triggered by the exit), and brings parity between VMX
   and SVM.

 - Add pending request and interrupt injection information to the kvm_exit and
   kvm_entry tracepoints respectively.

 - Fix a relatively benign flaw where KVM would end up redoing RDPKRU when
   loading guest/host PKRU, due to a refactoring of the kernel helpers that
   didn't account for KVM's pre-checking of the need to do WRPKRU.
2025-01-20 06:49:39 -05:00
Paolo Bonzini
892e7b8c27 Merge tag 'kvm-x86-vmx-6.14' of https://github.com/kvm-x86/linux into HEAD
KVM VMX changes for 6.14:

 - Fix a bug where KVM updates hardware's APICv cache of the highest ISR bit
   while L2 is active, while ultimately results in a hardware-accelerated L1
   EOI effectively being lost.

 - Honor event priority when emulating Posted Interrupt delivery during nested
   VM-Enter by queueing KVM_REQ_EVENT instead of immediately handling the
   interrupt.

 - Drop kvm_x86_ops.hwapic_irr_update() as KVM updates hardware's APICv cache
   prior to every VM-Enter.

 - Rework KVM's processing of the Page-Modification Logging buffer to reap
   entries in the same order they were created, i.e. to mark gfns dirty in the
   same order that hardware marked the page/PTE dirty.

 - Misc cleanups.
2025-01-20 06:48:53 -05:00
Juergen Gross
ae02ae16b7 x86/asm: Make serialize() always_inline
In order to allow serialize() to be used from noinstr code, make it
__always_inline.

Fixes: 0ef8047b73 ("x86/static-call: provide a way to do very early static-call updates")
Closes: https://lore.kernel.org/oe-kbuild-all/202412181756.aJvzih2K-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20241218100918.22167-1-jgross@suse.com
2025-01-16 16:51:17 +01:00
Dr. David Alan Gilbert
761bea182a platform/x86: intel: punit_ipc: Remove unused function
intel_punit_ipc_simple_command() was added in 2015 by
commit fdca4f16f5 ("platform:x86: add Intel P-Unit mailbox IPC driver")
but never used.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20241221234807.160473-1-linux@treblig.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2025-01-15 16:26:30 +02:00
David Woodhouse
7c61a3d8f7 x86/kexec: Use typedef for relocate_kernel_fn function prototype
Both i386 and x86_64 now copy the relocate_kernel() function into the control
page and execute it from there, using an open-coded function pointer.

Use a typedef for it instead.

  [ bp: Put relocate_kernel_ptr ptr arithmetic on a single line. ]

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250109140757.2841269-10-dwmw2@infradead.org
2025-01-14 13:09:08 +01:00
Ard Biesheuvel
60a34085c3 efi/libstub: Simplify GOP handling code
Use the LocateHandleBuffer() API and a __free() function to simplify the
logic that allocates a handle buffer to iterate over all GOP protocols
in the EFI database.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-01-14 08:35:08 +01:00
Qi Zheng
718b13861d x86: mm: free page table pages by RCU instead of semi RCU
Now, if CONFIG_MMU_GATHER_RCU_TABLE_FREE is selected, the page table pages
will be freed by semi RCU, that is:

 - batch table freeing: asynchronous free by RCU
 - single table freeing: IPI + synchronous free

In this way, the page table can be lockless traversed by disabling IRQ in
paths such as fast GUP.  But this is not enough to free the empty PTE page
table pages in paths other that munmap and exit_mmap path, because IPI
cannot be synchronized with rcu_read_lock() in pte_offset_map{_lock}().

In preparation for supporting empty PTE page table pages reclaimation, let
single table also be freed by RCU like batch table freeing.  Then we can
also use pte_offset_map() etc to prevent PTE page from being freed.

Like pte_free_defer(), we can also safely use ptdesc->pt_rcu_head to free
the page table pages:

 - The pt_rcu_head is unioned with pt_list and pmd_huge_pte.

 - For pt_list, it is used to manage the PGD page in x86. Fortunately
   tlb_remove_table() will not be used for free PGD pages, so it is safe
   to use pt_rcu_head.

 - For pmd_huge_pte, it is used for THPs, so it is safe.

After applying this patch, if CONFIG_PT_RECLAIM is enabled, the function
call of free_pte() is as follows:

free_pte
  pte_free_tlb
    __pte_free_tlb
      ___pte_free_tlb
        paravirt_tlb_remove_table
          tlb_remove_table [!CONFIG_PARAVIRT, Xen PV, Hyper-V, KVM]
            [no-free-memory slowpath:]
              tlb_table_invalidate
              tlb_remove_table_one
                __tlb_remove_table_one [frees via RCU]
            [fastpath:]
              tlb_table_flush
                tlb_remove_table_free [frees via RCU]
          native_tlb_remove_table [CONFIG_PARAVIRT on native]
            tlb_remove_table [see above]

Link: https://lkml.kernel.org/r/0287d442a973150b0e1019cc406e6322d148277a.1733305182.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:48 -08:00
Dr. David Alan Gilbert
58589c6a6e rtc: Remove hpet_rtc_dropped_irq()
hpet_rtc_dropped_irq() has been unused since
commit f52ef24be2 ("rtc/alpha: remove legacy rtc driver")

Remove it in rtc, and x86 hpet code.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20241215022356.181625-1-linux@treblig.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2025-01-13 23:07:18 +01:00