EPT exit qualification bit 6 is used when mode-based execute control
is enabled, and reflects user executable addresses. Rework name to
reflect the intention and add to EPT_VIOLATION_PROT_MASK, which allows
simplifying the return evaluation in
tdx_is_sept_violation_unexpected_pending a pinch.
Rework handling in __vmx_handle_ept_violation to unconditionally clear
EPT_VIOLATION_PROT_USER_EXEC until MBEC is implemented, as suggested by
Sean [1].
Note: Intel SDM Table 29-7 defines bit 6 as:
If the "mode-based execute control" VM-execution control is 0, the
value of this bit is undefined. If that control is 1, this bit is the
logical-AND of bit 10 in the EPT paging-structure entries used to
translate the guest-physical address of the access causing the EPT
violation. In this case, it indicates whether the guest-physical
address was executable for user-mode linear addresses.
[1] https://lore.kernel.org/all/aCJDzU1p_SFNRIJd@google.com/
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jon Kohler <jon@nutanix.com>
Message-ID: <20251223054806.1611168-2-jon@nutanix.com>
Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This helps avoiding more embarrassment to this maintainer, but also
will catch mistakes more easily for others.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM SVM changes for 7.1
- Fix and optimize IRQ window inhibit handling for AVIC (the tracking needs to
be per-vCPU, e.g. so that KVM doesn't prematurely re-enable AVIC if multiple
vCPUs have to-be-injected IRQs).
- Fix an undefined behavior warning where a crafty userspace can read the
"avic" module param before it's fully initialized.
- Fix a (likely benign) bug in the "OS-visible workarounds" handling, where
KVM could clobber state when enabling virtualization on multiple CPUs in
parallel, and clean up and optimize the code.
- Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains about a
"too large" size based purely on user input, and clean up and harden the
related pinning code.
- Disallow synchronizing a VMSA of an already-launched/encrypted vCPU, as
doing so for an SNP guest will trigger an RMP violation #PF and crash the
host.
- Protect all of sev_mem_enc_register_region() with kvm->lock to ensure
sev_guest() is stable for the entire of the function.
- Lock all vCPUs when synchronizing VMSAs for SNP guests to ensure the VMSA
page isn't actively being used.
- Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped queries are
required to hold kvm->lock (KVM has had multiple bugs due "is SEV?" checks
becoming stale), enforced by lockdep. Add and use vCPU-scoped APIs when
possible/appropriate, as all checks that originate from a vCPU are
guaranteed to be stable.
- Convert a pile of kvm->lock SEV code to guard().
KVM x86 VMXON and EFER.SVME extraction for 7.1
Move _only_ VMXON+VMXOFF and EFER.SVME toggling out of KVM (versus all of VMX
and SVM enabling) out of KVM and into the core kernel so that non-KVM TDX
enabling, e.g. for trusted I/O, can make SEAMCALLs without needing to ensure
KVM is fully loaded.
TIO isn't a hypervisor, and isn't trying to be a hypervisor. Specifically, TIO
should _never_ have it's own VMCSes (that are visible to the host; the
TDX-Module has it's own VMCSes to do SEAMCALL/SEAMRET), and so there is simply
no reason to move that functionality out of KVM.
With that out of the way, dealing with VMXON/VMXOFF and EFER.SVME is a fairly
simple refcounting game.
KVM nested SVM changes for 7.1 (with one common x86 fix)
- To minimize the probability of corrupting guest state, defer KVM's
non-architectural delivery of exception payloads (e.g. CR2 and DR6) until
consumption of the payload is imminent, and force delivery of the payload
in all paths where userspace saves relevant state.
- Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT to fix a
bug where L2's CR2 can get corrupted after a save/restore, e.g. if the VM
is migrated while L2 is faulting in memory.
- Fix a class of nSVM bugs where some fields written by the CPU are not
synchronized from vmcb02 to cached vmcb12 after VMRUN, and so are not
up-to-date when saved by KVM_GET_NESTED_STATE.
- Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE and
KVM_SET_{S}REGS could cause vmcb02 to be incorrectly initialized after
save+restore.
- Add a variety of missing nSVM consistency checks.
- Fix several bugs where KVM failed to correctly update VMCB fields on nested
#VMEXIT.
- Fix several bugs where KVM failed to correctly synthesize #UD or #GP for
SVM-related instructions.
- Add support for save+restore of virtualized LBRs (on SVM).
- Refactor various helpers and macros to improve clarity and (hopefully) make
the code easier to maintain.
- Aggressively sanitize fields when copying from vmcb12 to guard against
unintentionally allowing L1 to utilize yet-to-be-defined features.
- Fix several bugs where KVM botched rAX legality checks when emulating SVM
instructions. Note, KVM is still flawed in that KVM doesn't address size
prefix overrides for 64-bit guests; this should probably be documented as a
KVM erratum.
- Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails instead of
somewhat arbitrarily synthesizing #GP (i.e. don't bastardize AMD's already-
sketchy behavior of generating #GP if for "unsupported" addresses).
- Cache all used vmcb12 fields to further harden against TOCTOU bugs.
KVM x86 MMU changes for 7.1
- Fix an undefined behavior warning where a crafty userspace can read kvm.ko's
nx_huge_pages before it's fully initialized.
- Don't zero-allocate page tables that are used for splitting hugepages in the
TDP MMU, as KVM is guaranteed to set all SPTEs in the page table and thus
write all bytes.
- Bail early when trying to unsync 4KiB mappings if the target gfn can be
mapped with a 2MiB hugepage, to avoid the gfn hash lookup.
KVM VMX changes for 7.1
- Drop obsolete (largely ignored by hardwre) branch hint prefixes from the
VMX instruction macros, as saving a byte of code per instruction provides
more benefits than the (mostly) superfluous prefixes.
- Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a register
input when appropriate.
- Drop unnecessary parentheses in cpu_has_load_cet_ctrl() so as not to suggest
that "return (x & y);" is KVM's preferred style.
KVM x86 emulated MMIO changes for 7.1
Copy single-chunk MMIO write values into a persistent (per-fragment) field to
fix use-after-free stack bugs due to KVM dereferencing a stack pointer after an
exit to userspace.
Clean up and comment the emulated MMIO code to try to make it easier to
maintain (not necessarily "easy", but "easier").
KVM selftests changes for 7.1
- Add support for Hygon CPUs in KVM selftests.
- Fix a bug in the MSR test where it would get false failures on AMD/Hygon
CPUs with exactly one of RDPID or RDTSCP.
- Add an MADV_COLLAPSE testcase for guest_memfd as a regression test for a
bug where the kernel would attempt to collapse guest_memfd folios against
KVM's will.
KVM x86 misc changes for 7.1
- Advertise support for AVX512 Bit Matrix Multiply (BMM) when it's present in
hardware (no additional emulation/virtualization required).
- Immediately fail the build if a required #define is missing in one of KVM's
headers that is included multiple times.
- Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected exception,
mostly to prevent syzkaller from abusing the uAPI to trigger WARNs, but also
because it can help prevent userspace from unintentionally crashing the VM.
- Exempt SMM from CPUID faulting on Intel, as per the spec.
- Misc hardening and cleanup changes.
KVM guest_memfd changes for 7.1
Don't mark guest_memfd folios as accessed, as guest_memfd doesn't support
reclaim, the memory is unevictable, and there is no storage to write back to.
KVM/arm64 updates for 7.1
* New features:
- Add support for tracing in the standalone EL2 hypervisor code,
which should help both debugging and performance analysis.
This comes with a full infrastructure for 'remote' trace buffers
that can be exposed by non-kernel entities such as firmware.
- Add support for GICv5 Per Processor Interrupts (PPIs), as the
starting point for supporting the new GIC architecture in KVM.
- Finally add support for pKVM protected guests, with anonymous
memory being used as a backing store. About time!
* Improvements and bug fixes:
- Rework the dreaded user_mem_abort() function to make it more
maintainable, reducing the amount of state being exposed to
the various helpers and rendering a substantial amount of
state immutable.
- Expand the Stage-2 page table dumper to support NV shadow
page tables on a per-VM basis.
- Tidy up the pKVM PSCI proxy code to be slightly less hard
to follow.
- Fix both SPE and TRBE in non-VHE configurations so that they
do not generate spurious, out of context table walks that
ultimately lead to very bad HW lockups.
- A small set of patches fixing the Stage-2 MMU freeing in error
cases.
- Tighten-up accepted SMC immediate value to be only #0 for host
SMCCC calls.
- The usual cleanups and other selftest churn.
LoongArch KVM changes for v7.1
1. Use CSR_CRMD_PLV in kvm_arch_vcpu_in_kernel().
2. Let vcpu_is_preempted() a macro & some enhanments.
3. Add DMSINTC irqchip in kernel support.
4. Add KVM PMU test cases for tools/selftests.
KVM/riscv changes for 7.1
- Fix steal time shared memory alignment checks
- Fix vector context allocation leak
- Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi()
- Fix double-free of sdata in kvm_pmu_clear_snapshot_area()
- Fix integer overflow in kvm_pmu_validate_counter_mask()
- Fix shift-out-of-bounds in make_xfence_request()
- Fix lost write protection on huge pages during dirty logging
- Split huge pages during fault handling for dirty logging
- Skip CSR restore if VCPU is reloaded on the same core
- Implement kvm_arch_has_default_irqchip() for KVM selftests
- Factored-out ISA checks into separate sources
- Added hideleg to struct kvm_vcpu_config
- Factored-out VCPU config into separate sources
- Support configuration of per-VM HGATP mode from KVM user space
Pull EDAC fix from Borislav Petkov:
- Fix the error path ordering when the driver-private descriptor
allocation fails
* tag 'edac_urgent_for_7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/mc: Fix error path ordering in edac_mc_alloc()
Pull workqueue fix from Tejun Heo:
"This is a fix for a stall which triggers on ordered workqueues when
there are multiple inactive work items during workqueue property
changes through sysfs, which doesn't happen that frequently.
While really late, the fix is very low risk as it just repeats an
operation which is already being performed:
- Fix incomplete activation of multiple inactive works when
unplugging a pool_workqueue, where the pending_pwqs list
wasn't being updated for subsequent works"
* tag 'wq-for-7.0-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Add pool_workqueue to pending_pwqs list when unplugging multiple inactive works
Pull timer fixes from Thomas Gleixner:
"Two fixes for the time/timers subsystem:
- Invert the inverted fastpath decision in check_tick_dependency(),
which prevents NOHZ full to stop the tick. That's a regression
introduced in the 7.0 merge window.
- Prevent a unpriviledged DoS in the clockevents code, where user
space can starve the timer interrupt by arming a timerfd or posix
interval timer in a tight loop with an absolute expiry time in the
past. The fix turned out to be incomplete and was was amended
yesterday to make it work on some 20 years old AMD machines as
well. All issues with it have been confirmed to be resolved by
various reporters"
* tag 'timers-urgent-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clockevents: Prevent timer interrupt starvation
tick/nohz: Fix inverted return value in check_tick_dependency() fast path
Pull scheduler fix from Ingo Molnar:
"Fix DL server related slowdown to deferred fair tasks"
* tag 'sched-urgent-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Use revised wakeup rule for dl_server
Pull x86 MCE fix from Ingo Molnar:
"Fix incorrect hardware errors reported on Zen3 CPUs, such as bogus
L3 cache deferred errors (Yazen Ghannam)"
* tag 'ras-urgent-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce/amd: Filter bogus hardware errors on Zen3 clients
Pull perf fixes from Ingo Molnar:
"Four Intel uncore PMU driver fixes by Zide Chen"
* tag 'perf-urgent-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Remove extra double quote mark
perf/x86/intel/uncore: Fix die ID init and look up bugs
perf/x86/intel/uncore: Skip discovery table for offline dies
perf/x86/intel/uncore: Fix iounmap() leak on global_init failure
Leo reports an out-of-bounds access when parsing a certificate with
empty Basic Constraints or Key Usage extension because the first byte of
the extension is read before checking its length. Fix it.
The bug can be triggered by an unprivileged user by submitting a
specially crafted certificate to the kernel through the keyrings(7) API.
Leo has demonstrated this with a proof-of-concept program responsibly
disclosed off-list.
Fixes: 30eae2b037 ("KEYS: X.509: Parse Basic Constraints for CA")
Fixes: 567671281a ("KEYS: X.509: Parse Key Usage")
Reported-by: Leo Lin <leo@depthfirst.com> # off-list
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ignat Korchagin <ignat@linux.win>
Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When page reassignment was added to af_alg_pull_tsgl the original
loop wasn't updated so it may try to reassign one more page than
necessary.
Add the check to the reassignment so that this does not happen.
Also update the comment which still refers to the obsolete offset
argument.
Reported-by: syzbot+d23888375c2737c17ba5@syzkaller.appspotmail.com
Fixes: e870456d8e ("crypto: algif_skcipher - overhaul memory management")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull i2c fix from Wolfram Sang:
- imx: set dma_slave_config to 0 and avoid uninitialized fields
* tag 'i2c-for-7.0-final' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: imx: zero-initialize dma_slave_config for eDMA
Pull spi fixes from Mark Brown:
"A couple of changes here, one update to MAINTAINERS for the AMD
controller and a chnage from Pei Xiao which in spite of the changelog
is actually a fix - previously the zynq-qspi driver leaked a clock
enable for every flash operation it did which isn't good, these extra
enables were removed when doing the enable cleanup which are probably
a good idea anyway"
* tag 'spi-fix-v7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
MAINTAINERS: Update AMD SPI driver maintainers
spi: zynq-qspi: Simplify clock handling with devm_clk_get_enabled()
Pull regulator fix from Mark Brown:
"One last fix for v7.0, the BD72720 incorrectly described which DCDC is
tied to the LDO for its LDON-HEAD mode which automates using the DCDC
to more efficiently drop a supply for delivery via the LDO"
* tag 'regulator-fix-v7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: bd71828-regulator.c: Fix LDON-HEAD mode
Pull kvm fixes from Paolo Bonzini:
"s390:
- vsie: Fix races with partial gmap invalidations
x86:
- Use __DECLARE_FLEX_ARRAY() for UAPI structures with VLAs"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: vsie: Fix races with partial gmap invalidations
KVM: x86: Use __DECLARE_FLEX_ARRAY() for UAPI structures with VLAs
Pull tracing probe fix from Masami Hiramatsu:
"Reject non-closed empty immediate strings
Fix a buffer index underflow bug that occurred when passing an
non-closed empty immediate string to the probe event"
* tag 'probes-fixes-v7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/probe: reject non-closed empty immediate strings
Pull USB fix from Greg KH:
"Here is a single USB fix for a reported regression in a recent USB
typec patch for 7.0-final. Sorry for the late submission, but it does
fix a problem that people have been seeing with 7.0-rc7 and the stable
kernels (due to a backported fix from there.)
This has been in linux-next this week with no reported issues, and the
reporter (Takashi), has said it resolves the problem they were seeing"
* tag 'usb-7.0-final' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: typec: ucsi: skip connector validation before init
Pull input fixes from Dmitry Torokhov:
"Two fixes for force feedback handling in uinput driver:
- fix circular locking dependency in uinput
- fix potential corruption of uinput event queue"
* tag 'input-for-v7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: uinput - take event lock when submitting FF request "event"
Input: uinput - fix circular locking dependency with ff-core
KVM x86 fixes for 7.1
Declare flexible arrays in uAPI structures using __DECLARE_FLEX_ARRAY() so
that KVM's uAPI headers can be included in C++ projects.
Pull RISC-V updates from Paul Walmsley:
"Before v7.0 is released, fix a few issues with the CFI patchset,
merged earlier in v7.0-rc, that primarily affect interfaces to
non-kernel code:
- Improve the prctl() interface for per-task indirect branch landing
pad control to expand abbreviations and to resemble the speculation
control prctl() interface
- Expand the "LP" and "SS" abbreviations in the ptrace uapi header
file to "branch landing pad" and "shadow stack", to improve
readability
- Fix a typo in a CFI-related macro name in the ptrace uapi header
file
- Ensure that the indirect branch tracking state and shadow stack
state are unlocked immediately after an exec() on the new task so
that libc subsequently can control it
- While working in this area, clean up the kernel-internal,
cross-architecture prctl() function names by expanding the
abbreviations mentioned above"
* tag 'riscv-for-linus-v7.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
prctl: cfi: change the branch landing pad prctl()s to be more descriptive
riscv: ptrace: cfi: expand "SS" references to "shadow stack" in uapi headers
prctl: rename branch landing pad implementation functions to be more explicit
riscv: ptrace: expand "LP" references to "branch landing pads" in uapi headers
riscv: cfi: clear CFI lock status in start_thread()
riscv: ptrace: cfi: fix "PRACE" typo in uapi header
Pull drm fixes from Dave Airlie:
"Last set of fixes, a few vc4, and i915, one xe and one ethosu Kconfig
fix.
xe:
- Fix HW engine idleness unit conversion
i915:
- Drop check for changed VM in EXECBUF
- Fix refcount underflow race in intel_engine_park_heartbeat
- Do not use pipe_src as borders for SU area in PSR
vc4:
- runtime pm reference fix
- memory leak fixes
- locking fix
ethosu:
- make ARM only"
* tag 'drm-fixes-2026-04-11' of https://gitlab.freedesktop.org/drm/kernel:
drm/i915/gem: Drop check for changed VM in EXECBUF
drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat
drm/xe: Fix bug in idledly unit conversion
drm/i915/psr: Do not use pipe_src as borders for SU area
accel: ethosu: Add hardware dependency hint
drm/vc4: Protect madv read in vc4_gem_object_mmap() with madv_lock
drm/vc4: Fix a memory leak in hang state error path
drm/vc4: Fix memory leak of BO array in hang state
drm/vc4: Release runtime PM reference after binding V3D
Calvin reported an odd NMI watchdog lockup which claims that the CPU locked
up in user space. He provided a reproducer, which sets up a timerfd based
timer and then rearms it in a loop with an absolute expiry time of 1ns.
As the expiry time is in the past, the timer ends up as the first expiring
timer in the per CPU hrtimer base and the clockevent device is programmed
with the minimum delta value. If the machine is fast enough, this ends up
in a endless loop of programming the delta value to the minimum value
defined by the clock event device, before the timer interrupt can fire,
which starves the interrupt and consequently triggers the lockup detector
because the hrtimer callback of the lockup mechanism is never invoked.
As a first step to prevent this, avoid reprogramming the clock event device
when:
- a forced minimum delta event is pending
- the new expiry delta is less then or equal to the minimum delta
Thanks to Calvin for providing the reproducer and to Borislav for testing
and providing data from his Zen5 machine.
The problem is not limited to Zen5, but depending on the underlying
clock event device (e.g. TSC deadline timer on Intel) and the CPU speed
not necessarily observable.
This change serves only as the last resort and further changes will be made
to prevent this scenario earlier in the call chain as far as possible.
[ tglx: Updated to restore the old behaviour vs. !force and delta <= 0 and
fixed up the tick-broadcast handlers as pointed out by Borislav ]
Fixes: d316c57ff6 ("[PATCH] clockevents: add core functionality")
Reported-by: Calvin Owens <calvin@wbinvd.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Calvin Owens <calvin@wbinvd.org>
Tested-by: Borislav Petkov <bp@alien8.de>
Link: https://lore.kernel.org/lkml/acMe-QZUel-bBYUh@mozart.vkv.me/
Link: https://patch.msgid.link/20260407083247.562657657@kernel.org
Pull vfs fixes from Christian Brauner:
"The kernfs rbtree is keyed by (hash, ns, name) where the hash
is seeded with the raw namespace pointer via init_name_hash(ns).
The resulting hash values are exposed to userspace through
readdir seek positions, and the pointer-based ordering in
kernfs_name_compare() is observable through entry order.
Switch from raw pointers to ns_common::ns_id for both hashing
and comparison.
A preparatory commit first replaces all const void * namespace
parameters with const struct ns_common * throughout kernfs, sysfs,
and kobject so the code can access ns->ns_id. Also compare the
ns_id when hashes match in the rbtree to handle crafted collisions.
Also fix eventpoll RCU grace period issue and a cachefiles refcount
problem"
* tag 'vfs-7.0-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
kernfs: make directory seek namespace-aware
kernfs: use namespace id instead of pointer for hashing and comparison
kernfs: pass struct ns_common instead of const void * for namespace tags
eventpoll: defer struct eventpoll free to RCU grace period
cachefiles: fix incorrect dentry refcount in cachefiles_cull()
Pull turbostat fixes from Len Brown:
- Fix a memory allocation issue that could corrupt output values or
SEGV
- Fix a perf initilization issue that could exit on some HW + kernels
- Minor fixes
* tag 'turbostat-fixes-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
tools/power turbostat: Allow execution to continue after perf_l2_init() failure
tools/power turbostat: Fix delimiter bug in print functions
tools/power turbostat: Fix --show/--hide for individual cpuidle counters
tools/power turbostat: Fix incorrect format variable
tools/power turbostat: Consistently use print_float_value()
tools/power/turbostat: Fix microcode patch level output for AMD/Hygon
tools/power turbostat: Eliminate unnecessary data structure allocation
tools/power turbostat: Fix swidle header vs data display
tools/power turbostat: Fix illegal memory access when SMT is present and disabled
Pull pin control fixes from Linus Walleij:
"Some late pin control fixes. I'm not happy to have bugs so late in the
kernel cycle, but they are all driver specifics so I guess it's how it
is.
- Three fixes for the Intel pin control driver fixing the feature set
for the new silicon
- One fix for an IRQ storm in the MCP23S08 pin controller/GPIO
expander"
* tag 'pinctrl-v7.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: mcp23s08: Disable all pin interrupts during probe
pinctrl: intel: Enable 3-bit PAD_OWN feature
pinctrl: intel: Fix the revision for new features (1kOhm PD, HW debouncer)
pinctrl: intel: Improve capability support
Currently, if perf_l2_init() fails turbostat exits after issuing the
following error (which was encountered on AlderLake):
turbostat: perf_l2_init(cpu0, 0x0, 0xff24) REFS: Invalid argument
This occurs because perf_l2_init() calls err(). However, the code has been
written in such a manner that it is able to perform cleanup and continue.
Therefore, this issue can be addressed by changing the appropriate calls
to err() to warnx().
Additionally, correct the PMU type arguments passed to the warning strings
in the ecore and lcore blocks so the logs accurately reflect the failing
counter type.
Signed-off-by: David Arcari <darcari@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Pull Kbuild fixes from Nathan Chancellor:
- Make modules-cpio-pkg respect INSTALL_MOD_PATH so that it can be
used with distribution initramfs files that have a merged /usr,
such as Fedora
- Silence an instance of -Wunused-but-set-global, a strengthening
of -Wunused-but-set-variable in tip of tree Clang, in modpost,
as the variable for extra warnings is currently unused
* tag 'kbuild-fixes-7.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
modpost: Declare extra_warn with unused attribute
kbuild: modules-cpio-pkg: Respect INSTALL_MOD_PATH
When running as an SEV+ guest, treat SVM as unsupported even if CPUID (and
other reporting, e.g. MSRs) enumerate support for SVM, as KVM doesn't
support nested virtualization within an SEV VM (KVM would need to
explicitly share all VMCBs and other assets with the untrusted host), let
alone running nested VMs within SEV-ES+ guests (e.g. emulating VMLOAD,
VMSAVE, and VMRUN all require access to guest register state). And outside
of KVM, there is no in-tree user of SVM enabling.
Arguably, the hypervisor/VMM (e.g. QEMU) should clear SVM from guest CPUID
for SEV VMs, especially for SEV-ES+, but super duper technically, it's
feasible to run nested VMs in SEV+ guests (with many caveats). More
importantly, Linux-as-a-guest has played nice with SVM being advertised to
SEV+ guests for a long time.
Treating SVM as unsupported fixes a regression where a clean shutdown of
an SEV-ES+ guest degrades into an abrupt termination. Due to a gnarly
virtualization hole in SEV-ES (the architecture), where EFER must NOT be
intercepted by the hypervisor (because the untrusted hypervisor can't set
e.g. EFER.LME on behalf o the guest), the _host's_ EFER.SVME is visible to
the guest. Because EFER.SVME must be always '1' while in guest mode,
Linux-the-guest sees EFER.SVME=1 even when _its_ EFER.SVME is '0', thinks
it has enabled virtualization, and ultimately can cause
x86_svm_emergency_disable_virtualization_cpu() to execute STGI to ensure
GIF is enabled. Executing STGI _should_ be fine, except Linux is a also
wee bit paranoid when running as an SEV-ES guest.
Because L0 sees EFER.SVME=0 for the guest, a well-behaved L0 hypervisor
will intercept STGI (to inject #UD), and thus generate a #VC on the STGI.
Which, again, should be fine. Unfortunately, vc_check_opcode_bytes() fails
to account for STGI and other SVM instructions, throws a fatal error, and
triggers a termination request. In a perfect world, the #VC handler would
be more forgiving of unknown intercepts, especially when the #VC happened
on an instruction with exception fixup. For now, just fix the immediate
regression.
Fixes: 428afac5a8 ("KVM: x86: Move bulk of emergency virtualizaton logic to virt subsystem")
Reported-by: Srikanth Aithal <sraithal@amd.com>
Closes: https://lore.kernel.org/all/c820e242-9f3a-4210-b414-19d11b022404@amd.com
Link: https://patch.msgid.link/20260409191341.1932853-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Extract the lock-protected parts of SEV ASID allocation into a new helper
and opportunistically convert it to use guard() when acquiring the mutex.
Preserve the goto even though it's a little odd, as it's there's a fair
amount of subtlety that makes it surprisingly difficult to replicate the
functionality with a loop construct, and arguably using goto yields the
most readable code.
No functional change intended.
Signed-off-by: Carlos López <clopez@suse.de>
[sean: move code to separate helper, rework shortlog+changelog]
Link: https://patch.msgid.link/20260310234829.2608037-21-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
