Pull KVM x86 fixes from Paolo Bonzini:
- Disable AVIC on SNP-enabled systems that don't allow writes to the
virtual APIC page, as such hosts will hit unexpected RMP #PFs in the
host when running VMs of any flavor.
- Fix a WARN in the hypercall completion path due to KVM trying to
determine if a guest with protected register state is in 64-bit mode
(KVM's ABI is to assume such guests only make hypercalls in 64-bit
mode).
- Allow the guest to write to supported bits in MSR_AMD64_DE_CFG to fix
a regression with Windows guests, and because KVM's read-only
behavior appears to be entirely made up.
- Treat TDP MMU faults as spurious if the faulting access is allowed
given the existing SPTE. This fixes a benign WARN (other than the
WARN itself) due to unexpectedly replacing a writable SPTE with a
read-only SPTE.
- Emit a warning when KVM is configured with ignore_msrs=1 and also to
hide the MSRs that the guest is looking for from the kernel logs.
ignore_msrs can trick guests into assuming that certain processor
features are present, and this in turn leads to bogus bug reports.
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: let it be known that ignore_msrs is a bad idea
KVM: VMX: don't include '<linux/find.h>' directly
KVM: x86/mmu: Treat TDP MMU faults as spurious if access is already allowed
KVM: SVM: Allow guest writes to set MSR_AMD64_DE_CFG bits
KVM: x86: Play nice with protected guests in complete_hypercall_exit()
KVM: SVM: Disable AVIC on SNP-enabled system without HvInUseWrAllowed feature
KVM x86 fixes for 6.13:
- Disable AVIC on SNP-enabled systems that don't allow writes to the virtual
APIC page, as such hosts will hit unexpected RMP #PFs in the host when
running VMs of any flavor.
- Fix a WARN in the hypercall completion path due to KVM trying to determine
if a guest with protected register state is in 64-bit mode (KVM's ABI is to
assume such guests only make hypercalls in 64-bit mode).
- Allow the guest to write to supported bits in MSR_AMD64_DE_CFG to fix a
regression with Windows guests, and because KVM's read-only behavior appears
to be entirely made up.
- Treat TDP MMU faults as spurious if the faulting access is allowed given the
existing SPTE. This fixes a benign WARN (other than the WARN itself) due to
unexpectedly replacing a writable SPTE with a read-only SPTE.
When running KVM with ignore_msrs=1 and report_ignored_msrs=0, the user has
no clue that that the guest is being lied to. This may cause bug reports
such as https://gitlab.com/qemu-project/qemu/-/issues/2571, where enabling
a CPUID bit in QEMU caused Linux guests to try reading MSR_CU_DEF_ERR; and
being lied about the existence of MSR_CU_DEF_ERR caused the guest to assume
other things about the local APIC which were not true:
Sep 14 12:02:53 kernel: mce: [Firmware Bug]: Your BIOS is not setting up LVT offset 0x2 for deferred error IRQs correctly.
Sep 14 12:02:53 kernel: unchecked MSR access error: RDMSR from 0x852 at rIP: 0xffffffffb548ffa7 (native_read_msr+0x7/0x40)
Sep 14 12:02:53 kernel: Call Trace:
...
Sep 14 12:02:53 kernel: native_apic_msr_read+0x20/0x30
Sep 14 12:02:53 kernel: setup_APIC_eilvt+0x47/0x110
Sep 14 12:02:53 kernel: mce_amd_feature_init+0x485/0x4e0
...
Sep 14 12:02:53 kernel: [Firmware Bug]: cpu 0, try to use APIC520 (LVT offset 2) for vector 0xf4, but the register is already in use for vector 0x0 on this cpu
Without reported_ignored_msrs=0 at least the host kernel log will contain
enough information to avoid going on a wild goose chase. But if reports
about individual MSR accesses are being silenced too, at least complain
loudly the first time a VM is started.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull SoC fixes from Arnd Bergmann:
"Two more small fixes, correcting the cacheline size on Raspberry Pi 5
and fixing a logic mistake in the microchip mpfs firmware driver"
* tag 'soc-fixes-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5
firmware: microchip: fix UL_IAP lock check in mpfs_auto_update_state()
Pull misc fixes from Andrew Morton:
"25 hotfixes. 16 are cc:stable. 19 are MM and 6 are non-MM.
The usual bunch of singletons and doubletons - please see the relevant
changelogs for details"
* tag 'mm-hotfixes-stable-2024-12-21-12-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits)
mm: huge_memory: handle strsep not finding delimiter
alloc_tag: fix set_codetag_empty() when !CONFIG_MEM_ALLOC_PROFILING_DEBUG
alloc_tag: fix module allocation tags populated area calculation
mm/codetag: clear tags before swap
mm/vmstat: fix a W=1 clang compiler warning
mm: convert partially_mapped set/clear operations to be atomic
nilfs2: fix buffer head leaks in calls to truncate_inode_pages()
vmalloc: fix accounting with i915
mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy()
fork: avoid inappropriate uprobe access to invalid mm
nilfs2: prevent use of deleted inode
zram: fix uninitialized ZRAM not releasing backing device
zram: refuse to use zero sized block device as backing device
mm: use clear_user_(high)page() for arch with special user folio handling
mm: introduce cpu_icache_is_aliasing() across all architectures
mm: add RCU annotation to pte_offset_map(_lock)
mm: correctly reference merged VMA
mm: use aligned address in copy_user_gigantic_page()
mm: use aligned address in clear_gigantic_page()
mm: shmem: fix ShmemHugePages at swapout
...
Pull arm64 fix from Catalin Marinas:
"Fix a sparse warning in the arm64 signal code dealing with the user
shadow stack register, GCSPR_EL0"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64/signal: Silence sparse warning storing GCSPR_EL0
Pull drm fixes from Dave Airlie:
"Probably the last pull before Christmas holidays, I'll still be around
for most of the time anyways, nothing too major in here, bunch of
amdgpu and i915 along with a smattering of fixes across the board.
core:
- fix FB dependency
- avoid div by 0 more in vrefresh
- maintainers update
display:
- fix DP tunnel error path
dma-buf:
- fix !DEBUG_FS
sched:
- docs warning fix
panel:
- collection of misc panel fixes
i915:
- Reset engine utilization buffer before registration
- Ensure busyness counter increases motonically
- Accumulate active runtime on gt reset
amdgpu:
- Disable BOCO when CONFIG_HOTPLUG_PCI_PCIE is not enabled
- scheduler job fixes
- IP version check fixes
- devcoredump fix
- GPUVM update fix
- NBIO 2.5 fix
udmabuf:
- fix memory leak on last export
- sealing fixes
ivpu:
- fix NULL pointer
- fix memory leak
- fix WARN"
* tag 'drm-fixes-2024-12-20' of https://gitlab.freedesktop.org/drm/kernel: (33 commits)
drm/sched: Fix drm_sched_fini() docu generation
accel/ivpu: Fix WARN in ivpu_ipc_send_receive_internal()
accel/ivpu: Fix memory leak in ivpu_mmu_reserved_context_init()
accel/ivpu: Fix general protection fault in ivpu_bo_list()
drm/amdgpu/nbio7.0: fix IP version check
drm/amd: Update strapping for NBIO 2.5.0
drm/amdgpu: Handle NULL bo->tbo.resource (again) in amdgpu_vm_bo_update
drm/amdgpu: fix amdgpu_coredump
drm/amdgpu/smu14.0.2: fix IP version check
drm/amdgpu/gfx12: fix IP version check
drm/amdgpu/mmhub4.1: fix IP version check
drm/amdgpu/nbio7.11: fix IP version check
drm/amdgpu/nbio7.7: fix IP version check
drm/amdgpu: don't access invalid sched
drm/amd: Require CONFIG_HOTPLUG_PCI_PCIE for BOCO
drm: rework FB_CORE dependency
drm/fbdev: Select FB_CORE dependency for fbdev on DMA and TTM
fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE
i915/guc: Accumulate active runtime on gt reset
i915/guc: Ensure busyness counter increases motonically
...
We are seeing a sparse warning in gcs_restore_signal():
arch/arm64/kernel/signal.c:1054:9: sparse: sparse: cast removes address space '__user' of expression
when storing the final GCSPR_EL0 value back into the register, caused by
the fact that write_sysreg_s() casts the value it writes to a u64 which
sparse sees as discarding the __userness of the pointer.
Avoid this by treating the address as an integer, casting to a pointer only
when using it to write to userspace.
While we're at it also inline gcs_signal_cap_valid() into it's one user
and make equivalent updates to gcs_signal_entry().
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412082005.OBJ0BbWs-lkp@intel.com/
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241214-arm64-gcs-signal-sparse-v3-1-5e8d18fffc0c@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Treat slow-path TDP MMU faults as spurious if the access is allowed given
the existing SPTE to fix a benign warning (other than the WARN itself)
due to replacing a writable SPTE with a read-only SPTE, and to avoid the
unnecessary LOCK CMPXCHG and subsequent TLB flush.
If a read fault races with a write fault, fast GUP fails for any reason
when trying to "promote" the read fault to a writable mapping, and KVM
resolves the write fault first, then KVM will end up trying to install a
read-only SPTE (for a !map_writable fault) overtop a writable SPTE.
Note, it's not entirely clear why fast GUP fails, or if that's even how
KVM ends up with a !map_writable fault with a writable SPTE. If something
else is going awry, e.g. due to a bug in mmu_notifiers, then treating read
faults as spurious in this scenario could effectively mask the underlying
problem.
However, retrying the faulting access instead of overwriting an existing
SPTE is functionally correct and desirable irrespective of the WARN, and
fast GUP _can_ legitimately fail with a writable VMA, e.g. if the Accessed
bit in primary MMU's PTE is toggled and causes a PTE value mismatch. The
WARN was also recently added, specifically to track down scenarios where
KVM is unnecessarily overwrites SPTEs, i.e. treating the fault as spurious
doesn't regress KVM's bug-finding capabilities in any way. In short,
letting the WARN linger because there's a tiny chance it's due to a bug
elsewhere would be excessively paranoid.
Fixes: 1a175082b1 ("KVM: x86/mmu: WARN and flush if resolving a TDP MMU fault clears MMU-writable")
Reported-by: Lei Yang <leiyang@redhat.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219588
Tested-by: Lei Yang <leiyang@redhat.com>
Link: https://lore.kernel.org/r/20241218213611.3181643-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop KVM's arbitrary behavior of making DE_CFG.LFENCE_SERIALIZE read-only
for the guest, as rejecting writes can lead to guest crashes, e.g. Windows
in particular doesn't gracefully handle unexpected #GPs on the WRMSR, and
nothing in the AMD manuals suggests that LFENCE_SERIALIZE is read-only _if
it exists_.
KVM only allows LFENCE_SERIALIZE to be set, by the guest or host, if the
underlying CPU has X86_FEATURE_LFENCE_RDTSC, i.e. if LFENCE is guaranteed
to be serializing. So if the guest sets LFENCE_SERIALIZE, KVM will provide
the desired/correct behavior without any additional action (the guest's
value is never stuffed into hardware). And having LFENCE be serializing
even when it's not _required_ to be is a-ok from a functional perspective.
Fixes: 74a0e79df6 ("KVM: SVM: Disallow guest from changing userspace's MSR_AMD64_DE_CFG value")
Fixes: d1d93fa90f ("KVM: SVM: Add MSR-based feature support for serializing LFENCE")
Reported-by: Simon Pilkington <simonp.git@mailbox.org>
Closes: https://lore.kernel.org/all/52914da7-a97b-45ad-86a0-affdf8266c61@mailbox.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20241211172952.1477605-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit
hypercall when completing said hypercall. For guests with protected state,
e.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit
mode as the vCPU state needed to detect 64-bit mode is unavailable.
Hacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE
hypercall via VMGEXIT trips the WARN:
------------[ cut here ]------------
WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm]
Modules linked in: kvm_amd kvm ... [last unloaded: kvm]
CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp--392e932fa0f3-feat #470
Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024
RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm]
Call Trace:
<TASK>
kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm]
kvm_vcpu_ioctl+0x54f/0x630 [kvm]
__se_sys_ioctl+0x6b/0xc0
do_syscall_64+0x83/0x160
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
---[ end trace 0000000000000000 ]---
Fixes: b5aead0064 ("KVM: x86: Assume a 64-bit hypercall for guests with protected state")
Cc: stable@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20241128004344.4072099-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
On SNP-enabled system, VMRUN marks AVIC Backing Page as in-use while
the guest is running for both secure and non-secure guest. Any hypervisor
write to the in-use vCPU's AVIC backing page (e.g. to inject an interrupt)
will generate unexpected #PF in the host.
Currently, attempt to run AVIC guest would result in the following error:
BUG: unable to handle page fault for address: ff3a442e549cc270
#PF: supervisor write access in kernel mode
#PF: error_code(0x80000003) - RMP violation
PGD b6ee01067 P4D b6ee02067 PUD 10096d063 PMD 11c540063 PTE 80000001149cc163
SEV-SNP: PFN 0x1149cc unassigned, dumping non-zero entries in 2M PFN region: [0x114800 - 0x114a00]
...
Newer AMD system is enhanced to allow hypervisor to modify the backing page
for non-secure guest on SNP-enabled system. This enhancement is available
when the CPUID Fn8000_001F_EAX bit 30 is set (HvInUseWrAllowed).
This table describes AVIC support matrix w.r.t. SNP enablement:
| Non-SNP system | SNP system
-----------------------------------------------------
Non-SNP guest | AVIC Activate | AVIC Activate iff
| | HvInuseWrAllowed=1
-----------------------------------------------------
SNP guest | N/A | Secure AVIC
Therefore, check and disable AVIC in kvm_amd driver when the feature is not
available on SNP-enabled system.
See the AMD64 Architecture Programmer’s Manual (APM) Volume 2 for detail.
(https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/
programmer-references/40332.pdf)
Fixes: 216d106c7f ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20241104075845.7583-1-suravee.suthikulpanit@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Pull hyperv fixes from Wei Liu:
- Various fixes to Hyper-V tools in the kernel tree (Dexuan Cui, Olaf
Hering, Vitaly Kuznetsov)
- Fix a bug in the Hyper-V TSC page based sched_clock() (Naman Jain)
- Two bug fixes in the Hyper-V utility functions (Michael Kelley)
- Convert open-coded timeouts to secs_to_jiffies() in Hyper-V drivers
(Easwar Hariharan)
* tag 'hyperv-fixes-signed-20241217' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
tools/hv: reduce resource usage in hv_kvp_daemon
tools/hv: add a .gitignore file
tools/hv: reduce resouce usage in hv_get_dns_info helper
hv/hv_kvp_daemon: Pass NIC name to hv_get_dns_info as well
Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet
Drivers: hv: util: Don't force error code to ENODEV in util_probe()
tools/hv: terminate fcopy daemon if read from uio fails
drivers: hv: Convert open-coded timeouts to secs_to_jiffies()
tools: hv: change permissions of NetworkManager configuration file
x86/hyperv: Fix hv tsc page based sched_clock for hibernation
tools: hv: Fix a complier warning in the fcopy uio daemon
The Hexagon-specific constant extender optimization in LLVM may crash on
Linux kernel code [1], such as fs/bcache/btree_io.c after
commit 32ed4a620c ("bcachefs: Btree path tracepoints") in 6.12:
clang: llvm/lib/Target/Hexagon/HexagonConstExtenders.cpp:745: bool (anonymous namespace)::HexagonConstExtenders::ExtRoot::operator<(const HCE::ExtRoot &) const: Assertion `ThisB->getParent() == OtherB->getParent()' failed.
Stack dump:
0. Program arguments: clang --target=hexagon-linux-musl ... fs/bcachefs/btree_io.c
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module 'fs/bcachefs/btree_io.c'.
4. Running pass 'Hexagon constant-extender optimization' on function '@__btree_node_lock_nopath'
Without assertions enabled, there is just a hang during compilation.
This has been resolved in LLVM main (20.0.0) [2] and backported to LLVM
19.1.0 but the kernel supports LLVM 13.0.1 and newer, so disable the
constant expander optimization using the '-mllvm' option when using a
toolchain that is not fixed.
Cc: stable@vger.kernel.org
Link: https://github.com/llvm/llvm-project/issues/99714 [1]
Link: 68df06a0b2 [2]
Link: 2ab8d93061 [3]
Reviewed-by: Brian Cain <bcain@quicinc.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Set the cache-line-size parameter of the L2 cache for each core to the
correct value of 64 bytes.
Previously, the L2 cache line size was incorrectly set to 128 bytes
for the Broadcom BCM2712. This causes validation tests for the
Performance Application Programming Interface (PAPI) tool to fail as
they depend on sysfs accurately reporting cache line sizes.
The correct value of 64 bytes is stated in the official documentation of
the ARM Cortex A-72, which is linked in the comments of
arm64/boot/dts/broadcom/bcm2712.dtsi as the source for cache-line-size.
Fixes: faa3381267 ("arm64: dts: broadcom: Add minimal support for Raspberry Pi 5")
Signed-off-by: Willow Cunningham <willow.e.cunningham@maine.edu>
Link: https://lore.kernel.org/r/20241007212954.214724-1-willow.e.cunningham@maine.edu
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Pull s390 fixes from Alexander Gordeev:
- Fix DirectMap accounting in /proc/meminfo file
- Fix strscpy() return code handling that led to "unsigned 'len' is
never less than zero" warning
- Fix the calculation determining whether to use three- or four-level
paging: account KMSAN modules metadata
* tag 's390-6.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/mm: Consider KMSAN modules metadata for paging levels
s390/ipl: Fix never less than zero warning
s390/mm: Fix DirectMap accounting
Do not select BACKLIGHT_CLASS_DEVICE from FB_BACKLIGHT. The latter
only controls backlight support within fbdev core code and data
structures.
Make fbdev drivers depend on BACKLIGHT_CLASS_DEVICE and let users
select it explicitly. Fixes warnings about recursive dependencies,
such as
error: recursive dependency detected!
symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT
symbol FB_BACKLIGHT is selected by FB_SH_MOBILE_LCDC
symbol FB_SH_MOBILE_LCDC depends on FB_DEVICE
symbol FB_DEVICE depends on FB_CORE
symbol FB_CORE is selected by DRM_GEM_DMA_HELPER
symbol DRM_GEM_DMA_HELPER is selected by DRM_PANEL_ILITEK_ILI9341
symbol DRM_PANEL_ILITEK_ILI9341 depends on BACKLIGHT_CLASS_DEVICE
BACKLIGHT_CLASS_DEVICE is user-selectable, so making drivers adapt to
it is the correct approach in any case. For most drivers, backlight
support is also configurable separately.
v3:
- Select BACKLIGHT_CLASS_DEVICE in PowerMac defconfigs (Christophe)
- Fix PMAC_BACKLIGHT module dependency corner cases (Christophe)
v2:
- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)
- Fix fbdev driver-dependency corner case (Arnd)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241216074450.8590-2-tzimmermann@suse.de
Pull xen fixes from Juergen Gross:
"Fix xen netfront crash (XSA-465) and avoid using the hypercall page
that doesn't do speculation mitigations (XSA-466)"
* tag 'xsa465+xsa466-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: remove hypercall page
x86/xen: use new hypercall functions instead of hypercall page
x86/xen: add central hypercall functions
x86/xen: don't do PV iret hypercall through hypercall page
x86/static-call: provide a way to do very early static-call updates
objtool/x86: allow syscall instruction
x86: make get_cpu_vendor() accessible from Xen code
xen/netfront: fix crash when removing device
The hypercall page is no longer needed. It can be removed, as from the
Xen perspective it is optional.
But, from Linux's perspective, it removes naked RET instructions that
escape the speculative protections that Call Depth Tracking and/or
Untrain Ret are trying to achieve.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Call the Xen hypervisor via the new xen_hypercall_func static-call
instead of the hypercall page.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Add generic hypercall functions usable for all normal (i.e. not iret)
hypercalls. Depending on the guest type and the processor vendor
different functions need to be used due to the to be used instruction
for entering the hypervisor:
- PV guests need to use syscall
- HVM/PVH guests on Intel need to use vmcall
- HVM/PVH guests on AMD and Hygon need to use vmmcall
As PVH guests need to issue hypercalls very early during boot, there
is a 4th hypercall function needed for HVM/PVH which can be used on
Intel and AMD processors. It will check the vendor type and then set
the Intel or AMD specific function to use via static_call().
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Pull SoC fixes from Arnd Bergmann:
"Three small fixes for the soc tree:
- devicetee fix for the Arm Juno reference machine, to allow more
interesting PCI configurations
- build fix for SCMI firmware on the NXP i.MX platform
- fix for a race condition in Arm FF-A firmware"
* tag 'soc-fixes-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
arm64: dts: fvp: Update PCIe bus-range property
firmware: arm_ffa: Fix the race around setting ffa_dev->properties
firmware: arm_scmi: Fix i.MX build dependency
The calculation determining whether to use three- or four-level paging
didn't account for KMSAN modules metadata. Include this metadata in the
virtual memory size calculation to ensure correct paging mode selection
and avoiding potentially unnecessary physical memory size limitations.
Fixes: 65ca73f9fb ("s390/mm: define KMSAN metadata for vmalloc and modules")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Pull kvm fixes from Paolo Bonzini:
"ARM64:
- Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
SPE/TRBE initialization
- Align nested page table walker with the intended memory attribute
combining rules of the architecture
- Prevent userspace from constraining the advertised ASID width,
avoiding horrors of guest TLBIs not matching the intended context
in hardware
- Don't leak references on LPIs when insertion into the translation
cache fails
RISC-V:
- Replace csr_write() with csr_set() for HVIEN PMU overflow bit
x86:
- Cache CPUID.0xD XSTATE offsets+sizes during module init
On Intel's Emerald Rapids CPUID costs hundreds of cycles and there
are a lot of leaves under 0xD. Getting rid of the CPUIDs during
nested VM-Enter and VM-Exit is planned for the next release, for
now just cache them: even on Skylake that is 40% faster"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Cache CPUID.0xD XSTATE offsets+sizes during module init
RISC-V: KVM: Fix csr_write -> csr_set for HVIEN PMU overflow bit
KVM: arm64: vgic-its: Add error handling in vgic_its_cache_translation
KVM: arm64: Do not allow ID_AA64MMFR0_EL1.ASIDbits to be overridden
KVM: arm64: Fix S1/S2 combination when FWB==1 and S2 has Device memory type
arm64: Fix usage of new shifted MDCR_EL2 values
ARC GCC compiler is packaged starting from Fedora 39i and the GCC
variant of cross compile tools has arc-linux-gnu- prefix and not
arc-linux-. This is causing that CROSS_COMPILE variable is left unset.
This change allows builds without need to supply CROSS_COMPILE argument
if distro package is used.
Before this change:
$ make -j 128 ARCH=arc W=1 drivers/infiniband/hw/mlx4/
gcc: warning: ‘-mcpu=’ is deprecated; use ‘-mtune=’ or ‘-march=’ instead
gcc: error: unrecognized command-line option ‘-mmedium-calls’
gcc: error: unrecognized command-line option ‘-mlock’
gcc: error: unrecognized command-line option ‘-munaligned-access’
[1] https://packages.fedoraproject.org/pkgs/cross-gcc/gcc-arc-linux-gnu/index.html
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Pull arm64 fixes from Catalin Marinas:
- arm64 stacktrace: address some fallout from the recent changes to
unwinding across exception boundaries
- Ensure the arm64 signal delivery failure is recoverable - only
override the return registers after all the user accesses took place
- Fix the arm64 kselftest access to SVCR - only when SME is detected
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
kselftest/arm64: abi: fix SVCR detection
arm64: signal: Ensure signal delivery failure is recoverable
arm64: stacktrace: Don't WARN when unwinding other tasks
arm64: stacktrace: Skip reporting LR at exception boundaries
Pull RISC-V fixes from Palmer Dabbelt:
- avoid taking a mutex while resolving jump_labels in the mutex
implementation
- avoid trying to resolve the early boot DT pointer via the linear map
- avoid trying to IPI kfence TLB flushes, as kfence might flush with
IRQs disabled
- avoid calling PMD destructors on PMDs that were never constructed
* tag 'riscv-for-linus-6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: mm: Do not call pmd dtor on vmemmap page table teardown
riscv: Fix IPIs usage in kfence_protect_page()
riscv: Fix wrong usage of __pa() on a fixmap address
riscv: Fixup boot failure when CONFIG_DEBUG_RT_MUTEXES=y
Snapshot the output of CPUID.0xD.[1..n] during kvm.ko initiliaization to
avoid the overead of CPUID during runtime. The offset, size, and metadata
for CPUID.0xD.[1..n] sub-leaves does not depend on XCR0 or XSS values, i.e.
is constant for a given CPU, and thus can be cached during module load.
On Intel's Emerald Rapids, CPUID is *wildly* expensive, to the point where
recomputing XSAVE offsets and sizes results in a 4x increase in latency of
nested VM-Enter and VM-Exit (nested transitions can trigger
xstate_required_size() multiple times per transition), relative to using
cached values. The issue is easily visible by running `perf top` while
triggering nested transitions: kvm_update_cpuid_runtime() shows up at a
whopping 50%.
As measured via RDTSC from L2 (using KVM-Unit-Test's CPUID VM-Exit test
and a slightly modified L1 KVM to handle CPUID in the fastpath), a nested
roundtrip to emulate CPUID on Skylake (SKX), Icelake (ICX), and Emerald
Rapids (EMR) takes:
SKX 11650
ICX 22350
EMR 28850
Using cached values, the latency drops to:
SKX 6850
ICX 9000
EMR 7900
The underlying issue is that CPUID itself is slow on ICX, and comically
slow on EMR. The problem is exacerbated on CPUs which support XSAVES
and/or XSAVEC, as KVM invokes xstate_required_size() twice on each
runtime CPUID update, and because there are more supported XSAVE features
(CPUID for supported XSAVE feature sub-leafs is significantly slower).
SKX:
CPUID.0xD.2 = 348 cycles
CPUID.0xD.3 = 400 cycles
CPUID.0xD.4 = 276 cycles
CPUID.0xD.5 = 236 cycles
<other sub-leaves are similar>
EMR:
CPUID.0xD.2 = 1138 cycles
CPUID.0xD.3 = 1362 cycles
CPUID.0xD.4 = 1068 cycles
CPUID.0xD.5 = 910 cycles
CPUID.0xD.6 = 914 cycles
CPUID.0xD.7 = 1350 cycles
CPUID.0xD.8 = 734 cycles
CPUID.0xD.9 = 766 cycles
CPUID.0xD.10 = 732 cycles
CPUID.0xD.11 = 718 cycles
CPUID.0xD.12 = 734 cycles
CPUID.0xD.13 = 1700 cycles
CPUID.0xD.14 = 1126 cycles
CPUID.0xD.15 = 898 cycles
CPUID.0xD.16 = 716 cycles
CPUID.0xD.17 = 748 cycles
CPUID.0xD.18 = 776 cycles
Note, updating runtime CPUID information multiple times per nested
transition is itself a flaw, especially since CPUID is a mandotory
intercept on both Intel and AMD. E.g. KVM doesn't need to ensure emulated
CPUID state is up-to-date while running L2. That flaw will be fixed in a
future patch, as deferring runtime CPUID updates is more subtle than it
appears at first glance, the benefits aren't super critical to have once
the XSAVE issue is resolved, and caching CPUID output is desirable even if
KVM's updates are deferred.
Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241211013302.1347853-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit eaf62ce156 ("arm64/signal: Set up and restore the GCS
context for signal handlers") introduced a potential failure point
at the end of setup_return(). This is unfortunate as it is too late
to deliver a SIGSEGV: if that SIGSEGV is handled, the subsequent
sigreturn will end up returning to the original handler, which is
not the intention (since we failed to deliver that signal).
Make sure this does not happen by calling gcs_signal_entry()
at the very beginning of setup_return(), and add a comment just
after to discourage error cases being introduced from that point
onwards.
While at it, also take care of copy_siginfo_to_user(): since it may
fail, we shouldn't be calling it after setup_return() either. Call
it before setup_return() instead, and move the setting of X1/X2
inside setup_return() where it belongs (after the "point of no
failure").
Background: the first part of setup_rt_frame(), including
setup_sigframe(), has no impact on the execution of the interrupted
thread. The signal frame is written to the stack, but the stack
pointer remains unchanged. Failure at this stage can be recovered by
a SIGSEGV handler, and sigreturn will restore the original context,
at the point where the original signal occurred. On the other hand,
once setup_return() has updated registers including SP, the thread's
control flow has been modified and we must deliver the original
signal.
Fixes: eaf62ce156 ("arm64/signal: Set up and restore the GCS context for signal handlers")
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241210160940.2031997-1-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Instead of jumping to the Xen hypercall page for doing the iret
hypercall, directly code the required sequence in xen-asm.S.
This is done in preparation of no longer using hypercall page at all,
as it has shown to cause problems with speculation mitigations.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add static_call_update_early() for updating static-call targets in
very early boot.
This will be needed for support of Xen guest type specific hypercall
functions.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
In order to be able to differentiate between AMD and Intel based
systems for very early hypercalls without having to rely on the Xen
hypercall page, make get_cpu_vendor() non-static.
Refactor early_cpu_init() for the same reason by splitting out the
loop initializing cpu_devs() into an externally callable function.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Pull OpenRISC fixes from Stafford Horne:
- Fix from Masahiro Yamada to fix 6.13 OpenRISC boot issues after
vmlinux.lds.h symbol ordering was changed
- Code formatting fixups from Geert
* tag 'for-linus' of https://github.com/openrisc/linux:
openrisc: Fix misalignments in head.S
openrisc: place exception table at the head of vmlinux
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.
To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.
Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:
42a20f86dc ("sched: Add wrapper for get_wchan() to keep task blocked")
... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:
f8a00cef17 ("proc: restrict kernel stack dumps to root")
... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):
| for n in $(seq 1 10); do
| while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
| arch_stack_walk+0x1c8/0x370 (P)
| stack_trace_save_tsk+0x8c/0x108
| proc_pid_stack+0xb0/0x134
| proc_single_show+0x60/0x120
| seq_read_iter+0x104/0x438
| seq_read+0xf8/0x140
| vfs_read+0xc4/0x31c
| ksys_read+0x70/0x108
| __arm64_sys_read+0x1c/0x28
| invoke_syscall+0x48/0x104
| el0_svc_common.constprop.0+0x40/0xe0
| do_el0_svc+0x1c/0x28
| el0_svc+0x30/0xcc
| el0t_64_sync_handler+0x10c/0x138
| el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---
Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.
The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:
c2c6b27b5a ("arm64: stacktrace: unwind exception boundaries")
The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:
9f416319f4 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Fixes: c2c6b27b5a ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f416319f4 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
