44831 Commits

Author SHA1 Message Date
Linus Torvalds
2af9b20dbb Misc fixes:
- Fix a possible CPU hotplug deadlock bug caused by the new
    TSC synchronization code.
 
  - Fix a legacy PIC discovery bug that results in device troubles on
    affected systems, such as non-working keybards, etc.
 
  - Add a new Intel CPU model number to <asm/intel-family.h>.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes from Ingo Molnar:

 - Fix a possible CPU hotplug deadlock bug caused by the new TSC
   synchronization code

 - Fix a legacy PIC discovery bug that results in device troubles on
   affected systems, such as non-working keybards, etc

 - Add a new Intel CPU model number to <asm/intel-family.h>

* tag 'x86-urgent-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Defer marking TSC unstable to a worker
  x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility
  x86/cpu: Add model number for Intel Arrow Lake mobile processor
2023-10-28 08:15:07 -10:00
Thomas Gleixner
bd94d86f49 x86/tsc: Defer marking TSC unstable to a worker
Tetsuo reported the following lockdep splat when the TSC synchronization
fails during CPU hotplug:

   tsc: Marking TSC unstable due to check_tsc_sync_source failed
  
   WARNING: inconsistent lock state
   inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
   ffffffff8cfa1c78 (watchdog_lock){?.-.}-{2:2}, at: clocksource_watchdog+0x23/0x5a0
   {IN-HARDIRQ-W} state was registered at:
     _raw_spin_lock_irqsave+0x3f/0x60
     clocksource_mark_unstable+0x1b/0x90
     mark_tsc_unstable+0x41/0x50
     check_tsc_sync_source+0x14f/0x180
     sysvec_call_function_single+0x69/0x90

   Possible unsafe locking scenario:
     lock(watchdog_lock);
     <Interrupt>
       lock(watchdog_lock);

   stack backtrace:
    _raw_spin_lock+0x30/0x40
    clocksource_watchdog+0x23/0x5a0
    run_timer_softirq+0x2a/0x50
    sysvec_apic_timer_interrupt+0x6e/0x90

The reason is the recent conversion of the TSC synchronization function
during CPU hotplug on the control CPU to a SMP function call. In case
that the synchronization with the upcoming CPU fails, the TSC has to be
marked unstable via clocksource_mark_unstable().

clocksource_mark_unstable() acquires 'watchdog_lock', but that lock is
taken with interrupts enabled in the watchdog timer callback to minimize
interrupt disabled time. That's obviously a possible deadlock scenario,

Before that change the synchronization function was invoked in thread
context so this could not happen.

As it is not crucical whether the unstable marking happens slightly
delayed, defer the call to a worker thread which avoids the lock context
problem.

Fixes: 9d349d47f0e3 ("x86/smpboot: Make TSC synchronization function call based")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87zg064ceg.ffs@tglx
2023-10-27 20:36:57 +02:00
Thomas Gleixner
128b0c9781 x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility
David and a few others reported that on certain newer systems some legacy
interrupts fail to work correctly.

Debugging revealed that the BIOS of these systems leaves the legacy PIC in
uninitialized state which makes the PIC detection fail and the kernel
switches to a dummy implementation.

Unfortunately this fallback causes quite some code to fail as it depends on
checks for the number of legacy PIC interrupts or the availability of the
real PIC.

In theory there is no reason to use the PIC on any modern system when
IO/APIC is available, but the dependencies on the related checks cannot be
resolved trivially and on short notice. This needs lots of analysis and
rework.

The PIC detection has been added to avoid quirky checks and force selection
of the dummy implementation all over the place, especially in VM guest
scenarios. So it's not an option to revert the relevant commit as that
would break a lot of other scenarios.

One solution would be to try to initialize the PIC on detection fail and
retry the detection, but that puts the burden on everything which does not
have a PIC.

Fortunately the ACPI/MADT table header has a flag field, which advertises
in bit 0 that the system is PCAT compatible, which means it has a legacy
8259 PIC.

Evaluate that bit and if set avoid the detection routine and keep the real
PIC installed, which then gets initialized (for nothing) and makes the rest
of the code with all the dependencies work again.

Fixes: e179f6914152 ("x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately")
Reported-by: David Lazar <dlazar@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: David Lazar <dlazar@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218003
Link: https://lore.kernel.org/r/875y2u5s8g.ffs@tglx
2023-10-27 20:36:49 +02:00
Tony Luck
b99d70c0d1 x86/cpu: Add model number for Intel Arrow Lake mobile processor
For "reasons" Intel has code-named this CPU with a "_H" suffix.

[ dhansen: As usual, apply this and send it upstream quickly to
	   make it easier for anyone who is doing work that
	   consumes this. ]

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20231025202513.12358-1-tony.luck%40intel.com
2023-10-27 10:19:26 -07:00
Linus Torvalds
0df072ab65 Take care of a race between when the #VC exception is raised and when
the guest kernel gets to emulate certain instructions in SEV-{ES,SNP}
 guests by:
 
 - disabling emulation of MMIO instructions when coming from user mode
 
 - checking the IO permission bitmap before emulating IO instructions and
   verifying the memory operands of INS/OUTS insns.
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Merge tag 'sev_fixes_for_v6.6' of //git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "Take care of a race between when the #VC exception is raised and when
  the guest kernel gets to emulate certain instructions in SEV-{ES,SNP}
  guests by:

   - disabling emulation of MMIO instructions when coming from user mode

   - checking the IO permission bitmap before emulating IO instructions
     and verifying the memory operands of INS/OUTS insns"

* tag 'sev_fixes_for_v6.6' of //git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sev: Check for user-space IOIO pointing to kernel space
  x86/sev: Check IOBM for IOIO exceptions from user-space
  x86/sev: Disable MMIO emulation from user mode
2023-10-19 18:12:08 -07:00
Joerg Roedel
63e44bc520 x86/sev: Check for user-space IOIO pointing to kernel space
Check the memory operand of INS/OUTS before emulating the instruction.
The #VC exception can get raised from user-space, but the memory operand
can be manipulated to access kernel memory before the emulation actually
begins and after the exception handler has run.

  [ bp: Massage commit message. ]

Fixes: 597cfe48212a ("x86/boot/compressed/64: Setup a GHCB-based VC Exception handler")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
2023-10-17 10:58:16 +02:00
Linus Torvalds
86d6a628a2 ARM:
- Fix the handling of the phycal timer offset when FEAT_ECV
   and CNTPOFF_EL2 are implemented.
 
 - Restore the functionnality of Permission Indirection that
   was broken by the Fine Grained Trapping rework
 
 - Cleanup some PMU event sharing code
 
 MIPS:
 
 - Fix W=1 build.
 
 s390:
 
 - One small fix for gisa to avoid stalls.
 
 x86:
 
 - Truncate writes to PMU counters to the counter's width to avoid spurious
   overflows when emulating counter events in software.
 
 - Set the LVTPC entry mask bit when handling a PMI (to match Intel-defined
   architectural behavior).
 
 - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work to
   kick the guest out of emulated halt.
 
 - Fix for loading XSAVE state from an old kernel into a new one.
 
 - Fixes for AMD AVIC
 
 selftests:
 
 - Play nice with %llx when formatting guest printf and assert statements.
 
 - Clean up stale test metadata.
 
 - Zero-initialize structures in memslot perf test to workaround a suspected
   "may be used uninitialized" false positives from GCC.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Fix the handling of the phycal timer offset when FEAT_ECV and
     CNTPOFF_EL2 are implemented

   - Restore the functionnality of Permission Indirection that was
     broken by the Fine Grained Trapping rework

   - Cleanup some PMU event sharing code

  MIPS:

   - Fix W=1 build

  s390:

   - One small fix for gisa to avoid stalls

  x86:

   - Truncate writes to PMU counters to the counter's width to avoid
     spurious overflows when emulating counter events in software

   - Set the LVTPC entry mask bit when handling a PMI (to match
     Intel-defined architectural behavior)

   - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work
     to kick the guest out of emulated halt

   - Fix for loading XSAVE state from an old kernel into a new one

   - Fixes for AMD AVIC

  selftests:

   - Play nice with %llx when formatting guest printf and assert
     statements

   - Clean up stale test metadata

   - Zero-initialize structures in memslot perf test to workaround a
     suspected 'may be used uninitialized' false positives from GCC"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: arm64: timers: Correctly handle TGE flip with CNTPOFF_EL2
  KVM: arm64: POR{E0}_EL1 do not need trap handlers
  KVM: arm64: Add nPIR{E0}_EL1 to HFG traps
  KVM: MIPS: fix -Wunused-but-set-variable warning
  KVM: arm64: pmu: Drop redundant check for non-NULL kvm_pmu_events
  KVM: SVM: Fix build error when using -Werror=unused-but-set-variable
  x86: KVM: SVM: refresh AVIC inhibition in svm_leave_nested()
  x86: KVM: SVM: add support for Invalid IPI Vector interception
  x86: KVM: SVM: always update the x2avic msr interception
  KVM: selftests: Force load all supported XSAVE state in state test
  KVM: selftests: Load XSAVE state into untouched vCPU during state test
  KVM: selftests: Touch relevant XSAVE state in guest for state test
  KVM: x86: Constrain guest-supported xfeatures only at KVM_GET_XSAVE{2}
  x86/fpu: Allow caller to constrain xfeatures when copying to uabi buffer
  KVM: selftests: Zero-initialize entire test_result in memslot perf test
  KVM: selftests: Remove obsolete and incorrect test case metadata
  KVM: selftests: Treat %llx like %lx when formatting guest printf
  KVM: x86/pmu: Synthesize at most one PMI per VM-exit
  KVM: x86: Mask LVTPC when handling a PMI
  KVM: x86/pmu: Truncate counter value to allowed width on write
  ...
2023-10-16 18:34:17 -07:00
Linus Torvalds
fbe1bf1e5f Revert "x86/smp: Put CPUs into INIT on shutdown if possible"
This reverts commit 45e34c8af58f23db4474e2bfe79183efec09a18b, and the
two subsequent fixes to it:

  3f874c9b2aae ("x86/smp: Don't send INIT to non-present and non-booted CPUs")
  b1472a60a584 ("x86/smp: Don't send INIT to boot CPU")

because it seems to result in hung machines at shutdown.  Particularly
some Dell machines, but Thomas says

 "The rest seems to be Lenovo and Sony with Alderlake/Raptorlake CPUs -
  at least that's what I could figure out from the various bug reports.

  I don't know which CPUs the DELL machines have, so I can't say it's a
  pattern.

  I agree with the revert for now"

Ashok Raj chimes in:

 "There was a report (probably this same one), and it turns out it was a
  bug in the BIOS SMI handler.

  The client BIOS's were waiting for the lowest APICID to be the SMI
  rendevous master. If this is MeteorLake, the BSP wasn't the one with
  the lowest APIC and it triped here.

  The BIOS change is also being pushed to others for assimilation :)

  Server BIOS's had this correctly for a while now"

and it does look likely to be some bad interaction between SMI and the
non-BSP cores having put into INIT (and thus unresponsive until reset).

Link: https://bbs.archlinux.org/viewtopic.php?pid=2124429
Link: https://www.reddit.com/r/openSUSE/comments/16qq99b/tumbleweed_shutdown_did_not_finish_completely/
Link: https://forum.artixlinux.org/index.php/topic,5997.0.html
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2241279
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-10-15 12:02:02 -07:00
Linus Torvalds
ddf2085598 Fix a Longsoon build warning by harmonizing the arch_[un]register_cpu()
prototypes between architectures.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'smp-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug fix from Ingo Molnar:
 "Fix a Longsoon build warning by harmonizing the
  arch_[un]register_cpu() prototypes between architectures"

* tag 'smp-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu-hotplug: Provide prototypes for arch CPU registration
2023-10-15 08:44:56 -07:00
Paolo Bonzini
88e4cd893f KVM x86/pmu fixes for 6.6:
- Truncate writes to PMU counters to the counter's width to avoid spurious
    overflows when emulating counter events in software.
 
  - Set the LVTPC entry mask bit when handling a PMI (to match Intel-defined
    architectural behavior).
 
  - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work to
    kick the guest out of emulated halt.
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Merge tag 'kvm-x86-pmu-6.6-fixes' of https://github.com/kvm-x86/linux into HEAD

KVM x86/pmu fixes for 6.6:

 - Truncate writes to PMU counters to the counter's width to avoid spurious
   overflows when emulating counter events in software.

 - Set the LVTPC entry mask bit when handling a PMI (to match Intel-defined
   architectural behavior).

 - Treat KVM_REQ_PMI as a wake event instead of queueing host IRQ work to
   kick the guest out of emulated halt.
2023-10-15 08:24:18 -04:00
Linus Torvalds
dc9b2e683b Fix a false-positive KASAN warning, fix an AMD erratum on Zen4 CPUs,
and fix kernel-doc build warnings.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Fix a false-positive KASAN warning, fix an AMD erratum on Zen4 CPUs,
  and fix kernel-doc build warnings"

* tag 'x86-urgent-2023-10-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Disable KASAN in apply_alternatives()
  x86/cpu: Fix AMD erratum #1485 on Zen4-based CPUs
  x86/resctrl: Fix kernel-doc warnings
2023-10-14 15:32:20 -07:00
Linus Torvalds
23931d9353 Fix an LBR sampling bug.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2023-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf event fix from Ingo Molnar:
 "Fix an LBR sampling bug"

* tag 'perf-urgent-2023-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/lbr: Filter vsyscall addresses
2023-10-14 15:09:55 -07:00
Kirill A. Shutemov
d35652a5fc x86/alternatives: Disable KASAN in apply_alternatives()
Fei has reported that KASAN triggers during apply_alternatives() on
a 5-level paging machine:

	BUG: KASAN: out-of-bounds in rcu_is_watching()
	Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0
	...
	__asan_load4()
	rcu_is_watching()
	trace_hardirqs_on()
	text_poke_early()
	apply_alternatives()
	...

On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57)
gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on
__VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled().

KASAN gets confused when apply_alternatives() patches the
KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START
static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue.

Fix it for real by disabling KASAN while the kernel is patching alternatives.

[ mingo: updated the changelog ]

Fixes: 6657fca06e3f ("x86/mm: Allow to boot without LA57 if CONFIG_X86_5LEVEL=y")
Reported-by: Fei Yang <fei.yang@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231012100424.1456-1-kirill.shutemov@linux.intel.com
2023-10-12 20:27:16 +02:00
Tom Lendacky
3e93467346 KVM: SVM: Fix build error when using -Werror=unused-but-set-variable
Commit 916e3e5f26ab ("KVM: SVM: Do not use user return MSR support for
virtualized TSC_AUX") introduced a local variable used for the rdmsr()
function for the high 32-bits of the MSR value. This variable is not used
after being set and triggers a warning or error, when treating warnings
as errors, when the unused-but-set-variable flag is set. Mark this
variable as __maybe_unused to fix this.

Fixes: 916e3e5f26ab ("KVM: SVM: Do not use user return MSR support for virtualized TSC_AUX")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <0da9874b6e9fcbaaa5edeb345d7e2a7c859fc818.1696271334.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-12 11:09:36 -04:00
Maxim Levitsky
3fdc6087df x86: KVM: SVM: refresh AVIC inhibition in svm_leave_nested()
svm_leave_nested() similar to a nested VM exit, get the vCPU out of nested
mode and thus should end the local inhibition of AVIC on this vCPU.

Failure to do so, can lead to hangs on guest reboot.

Raise the KVM_REQ_APICV_UPDATE request to refresh the AVIC state of the
current vCPU in this case.

Fixes: f44509f849fe ("KVM: x86: SVM: allow AVIC to co-exist with a nested guest running")
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230928173354.217464-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-12 11:09:00 -04:00
Maxim Levitsky
2dcf37abf9 x86: KVM: SVM: add support for Invalid IPI Vector interception
In later revisions of AMD's APM, there is a new 'incomplete IPI' exit code:

"Invalid IPI Vector - The vector for the specified IPI was set to an
illegal value (VEC < 16)"

Note that tests on Zen2 machine show that this VM exit doesn't happen and
instead AVIC just does nothing.

Add support for this exit code by doing nothing, instead of filling
the kernel log with errors.

Also replace an unthrottled 'pr_err()' if another unknown incomplete
IPI exit happens with vcpu_unimpl()

(e.g in case AMD adds yet another 'Invalid IPI' exit reason)

Cc: <stable@vger.kernel.org>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230928173354.217464-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-12 11:08:59 -04:00
Maxim Levitsky
b65235f6e1 x86: KVM: SVM: always update the x2avic msr interception
The following problem exists since x2avic was enabled in the KVM:

svm_set_x2apic_msr_interception is called to enable the interception of
the x2apic msrs.

In particular it is called at the moment the guest resets its apic.

Assuming that the guest's apic was in x2apic mode, the reset will bring
it back to the xapic mode.

The svm_set_x2apic_msr_interception however has an erroneous check for
'!apic_x2apic_mode()' which prevents it from doing anything in this case.

As a result of this, all x2apic msrs are left unintercepted, and that
exposes the bare metal x2apic (if enabled) to the guest.
Oops.

Remove the erroneous '!apic_x2apic_mode()' check to fix that.

This fixes CVE-2023-5090

Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode")
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230928173354.217464-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-12 11:08:59 -04:00
Sean Christopherson
8647c52e95 KVM: x86: Constrain guest-supported xfeatures only at KVM_GET_XSAVE{2}
Mask off xfeatures that aren't exposed to the guest only when saving guest
state via KVM_GET_XSAVE{2} instead of modifying user_xfeatures directly.
Preserving the maximal set of xfeatures in user_xfeatures restores KVM's
ABI for KVM_SET_XSAVE, which prior to commit ad856280ddea ("x86/kvm/fpu:
Limit guest user_xfeatures to supported bits of XCR0") allowed userspace
to load xfeatures that are supported by the host, irrespective of what
xfeatures are exposed to the guest.

There is no known use case where userspace *intentionally* loads xfeatures
that aren't exposed to the guest, but the bug fixed by commit ad856280ddea
was specifically that KVM_GET_SAVE{2} would save xfeatures that weren't
exposed to the guest, e.g. would lead to userspace unintentionally loading
guest-unsupported xfeatures when live migrating a VM.

Restricting KVM_SET_XSAVE to guest-supported xfeatures is especially
problematic for QEMU-based setups, as QEMU has a bug where instead of
terminating the VM if KVM_SET_XSAVE fails, QEMU instead simply stops
loading guest state, i.e. resumes the guest after live migration with
incomplete guest state, and ultimately results in guest data corruption.

Note, letting userspace restore all host-supported xfeatures does not fix
setups where a VM is migrated from a host *without* commit ad856280ddea,
to a target with a subset of host-supported xfeatures.  However there is
no way to safely address that scenario, e.g. KVM could silently drop the
unsupported features, but that would be a clear violation of KVM's ABI and
so would require userspace to opt-in, at which point userspace could
simply be updated to sanitize the to-be-loaded XSAVE state.

Reported-by: Tyler Stachecki <stachecki.tyler@gmail.com>
Closes: https://lore.kernel.org/all/20230914010003.358162-1-tstachecki@bloomberg.net
Fixes: ad856280ddea ("x86/kvm/fpu: Limit guest user_xfeatures to supported bits of XCR0")
Cc: stable@vger.kernel.org
Cc: Leonardo Bras <leobras@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Message-Id: <20230928001956.924301-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-12 11:08:58 -04:00
Sean Christopherson
18164f66e6 x86/fpu: Allow caller to constrain xfeatures when copying to uabi buffer
Plumb an xfeatures mask into __copy_xstate_to_uabi_buf() so that KVM can
constrain which xfeatures are saved into the userspace buffer without
having to modify the user_xfeatures field in KVM's guest_fpu state.

KVM's ABI for KVM_GET_XSAVE{2} is that features that are not exposed to
guest must not show up in the effective xstate_bv field of the buffer.
Saving only the guest-supported xfeatures allows userspace to load the
saved state on a different host with a fewer xfeatures, so long as the
target host supports the xfeatures that are exposed to the guest.

KVM currently sets user_xfeatures directly to restrict KVM_GET_XSAVE{2} to
the set of guest-supported xfeatures, but doing so broke KVM's historical
ABI for KVM_SET_XSAVE, which allows userspace to load any xfeatures that
are supported by the *host*.

Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230928001956.924301-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-12 11:08:58 -04:00
Russell King (Oracle)
c4dd854f74 cpu-hotplug: Provide prototypes for arch CPU registration
Provide common prototypes for arch_register_cpu() and
arch_unregister_cpu(). These are called by acpi_processor.c, with weak
versions, so the prototype for this is already set. It is generally not
necessary for function prototypes to be conditional on preprocessor macros.

Some architectures (e.g. Loongarch) are missing the prototype for this, and
rather than add it to Loongarch's asm/cpu.h, do the job once for everyone.

Since this covers everyone, remove the now unnecessary prototypes in
asm/cpu.h, and therefore remove the 'static' from one of ia64's
arch_register_cpu() definitions.

[ tglx: Bring back the ia64 part and remove the ACPI prototypes ]

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1qkoRr-0088Q8-Da@rmk-PC.armlinux.org.uk
2023-10-11 14:27:37 +02:00
Borislav Petkov (AMD)
f454b18e07 x86/cpu: Fix AMD erratum #1485 on Zen4-based CPUs
Fix erratum #1485 on Zen4 parts where running with STIBP disabled can
cause an #UD exception. The performance impact of the fix is negligible.

Reported-by: René Rebe <rene@exactcode.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: René Rebe <rene@exactcode.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@exactcode.com
2023-10-11 11:00:11 +02:00
Linus Torvalds
b711538a40 hyperv-fixes for v6.6-rc6
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Merge tag 'hyperv-fixes-signed-20231009' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - fixes for Hyper-V VTL code (Saurabh Sengar and Olaf Hering)

 - fix hv_kvp_daemon to support keyfile based connection profile
   (Shradha Gupta)

* tag 'hyperv-fixes-signed-20231009' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv/hv_kvp_daemon:Support for keyfile based connection profile
  hyperv: reduce size of ms_hyperv_info
  x86/hyperv: Add common print prefix "Hyper-V" in hv_init
  x86/hyperv: Remove hv_vtl_early_init initcall
  x86/hyperv: Restrict get_vtl to only VTL platforms
2023-10-10 11:01:21 -07:00
Joerg Roedel
b9cb9c4558 x86/sev: Check IOBM for IOIO exceptions from user-space
Check the IO permission bitmap (if present) before emulating IOIO #VC
exceptions for user-space. These permissions are checked by hardware
already before the #VC is raised, but due to the VC-handler decoding
race it needs to be checked again in software.

Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Dohrmann <erbse.13@gmx.de>
Cc: <stable@kernel.org>
2023-10-09 15:47:57 +02:00
Borislav Petkov (AMD)
a37cd2a59d x86/sev: Disable MMIO emulation from user mode
A virt scenario can be constructed where MMIO memory can be user memory.
When that happens, a race condition opens between when the hardware
raises the #VC and when the #VC handler gets to emulate the instruction.

If the MOVS is replaced with a MOVS accessing kernel memory in that
small race window, then write to kernel memory happens as the access
checks are not done at emulation time.

Disable MMIO emulation in user mode temporarily until a sensible use
case appears and justifies properly handling the race window.

Fixes: 0118b604c2c9 ("x86/sev-es: Handle MMIO String Instructions")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Dohrmann <erbse.13@gmx.de>
Cc: <stable@kernel.org>
2023-10-09 15:45:34 +02:00
JP Kobryn
e53899771a perf/x86/lbr: Filter vsyscall addresses
We found that a panic can occur when a vsyscall is made while LBR sampling
is active. If the vsyscall is interrupted (NMI) for perf sampling, this
call sequence can occur (most recent at top):

    __insn_get_emulate_prefix()
    insn_get_emulate_prefix()
    insn_get_prefixes()
    insn_get_opcode()
    decode_branch_type()
    get_branch_type()
    intel_pmu_lbr_filter()
    intel_pmu_handle_irq()
    perf_event_nmi_handler()

Within __insn_get_emulate_prefix() at frame 0, a macro is called:

    peek_nbyte_next(insn_byte_t, insn, i)

Within this macro, this dereference occurs:

    (insn)->next_byte

Inspecting registers at this point, the value of the next_byte field is the
address of the vsyscall made, for example the location of the vsyscall
version of gettimeofday() at 0xffffffffff600000. The access to an address
in the vsyscall region will trigger an oops due to an unhandled page fault.

To fix the bug, filtering for vsyscalls can be done when
determining the branch type. This patch will return
a "none" branch if a kernel address if found to lie in the
vsyscall region.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
2023-10-08 12:25:18 +02:00
Randy Dunlap
025d5ac978 x86/resctrl: Fix kernel-doc warnings
The kernel test robot reported kernel-doc warnings here:

  monitor.c:34: warning: Cannot understand  * @rmid_free_lru    A least recently used list of free RMIDs on line 34 - I thought it was a doc line
  monitor.c:41: warning: Cannot understand  * @rmid_limbo_count     count of currently unused but (potentially) on line 41 - I thought it was a doc line
  monitor.c:50: warning: Cannot understand  * @rmid_entry - The entry in the limbo and free lists.  on line 50 - I thought it was a doc line

We don't have a syntax for documenting individual data items via
kernel-doc, so remove the "/**" kernel-doc markers and add a hyphen
for consistency.

Fixes: 6a445edce657 ("x86/intel_rdt/cqm: Add RDT monitoring initialization")
Fixes: 24247aeeabe9 ("x86/intel_rdt/cqm: Improve limbo list processing")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20231006235132.16227-1-rdunlap@infradead.org
2023-10-08 11:45:16 +02:00
Tom Lendacky
62d5e970d0 x86/sev: Change npages to unsigned long in snp_accept_memory()
In snp_accept_memory(), the npages variables value is calculated from
phys_addr_t variables but is an unsigned int. A very large range passed
into snp_accept_memory() could lead to truncating npages to zero. This
doesn't happen at the moment but let's be prepared.

Fixes: 6c3211796326 ("x86/sev: Add SNP-specific unaccepted memory support")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/6d511c25576494f682063c9fb6c705b526a3757e.1687441505.git.thomas.lendacky@amd.com
2023-10-02 14:55:41 +02:00
Tom Lendacky
6bc6f7d9d7 x86/sev: Use the GHCB protocol when available for SNP CPUID requests
SNP retrieves the majority of CPUID information from the SNP CPUID page.
But there are times when that information needs to be supplemented by the
hypervisor, for example, obtaining the initial APIC ID of the vCPU from
leaf 1.

The current implementation uses the MSR protocol to retrieve the data from
the hypervisor, even when a GHCB exists. The problem arises when an NMI
arrives on return from the VMGEXIT. The NMI will be immediately serviced
and may generate a #VC requiring communication with the hypervisor.

Since a GHCB exists in this case, it will be used. As part of using the
GHCB, the #VC handler will write the GHCB physical address into the GHCB
MSR and the #VC will be handled.

When the NMI completes, processing resumes at the site of the VMGEXIT
which is expecting to read the GHCB MSR and find a CPUID MSR protocol
response. Since the NMI handling overwrote the GHCB MSR response, the
guest will see an invalid reply from the hypervisor and self-terminate.

Fix this problem by using the GHCB when it is available. Any NMI
received is properly handled because the GHCB contents are copied into
a backup page and restored on NMI exit, thus preserving the active GHCB
request or result.

  [ bp: Touchups. ]

Fixes: ee0bfa08a345 ("x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/a5856fa1ebe3879de91a8f6298b6bbd901c61881.1690578565.git.thomas.lendacky@amd.com
2023-10-02 14:55:39 +02:00
Linus Torvalds
d2c5231581 Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain
to issues which were introduced after 6.5.
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Merge tag 'mm-hotfixes-stable-2023-10-01-08-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Fourteen hotfixes, eleven of which are cc:stable. The remainder
  pertain to issues which were introduced after 6.5"

* tag 'mm-hotfixes-stable-2023-10-01-08-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  Crash: add lock to serialize crash hotplug handling
  selftests/mm: fix awk usage in charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh that may cause error
  mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and MPOL_MF_MOVE are specified
  mm/damon/vaddr-test: fix memory leak in damon_do_test_apply_three_regions()
  mm, memcg: reconsider kmem.limit_in_bytes deprecation
  mm: zswap: fix potential memory corruption on duplicate store
  arm64: hugetlb: fix set_huge_pte_at() to work with all swap entries
  mm: hugetlb: add huge page size param to set_huge_pte_at()
  maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states
  maple_tree: add mas_is_active() to detect in-tree walks
  nilfs2: fix potential use after free in nilfs_gccache_submit_read_data()
  mm: abstract moving to the next PFN
  mm: report success more often from filemap_map_folio_range()
  fs: binfmt_elf_efpic: fix personality for ELF-FDPIC
2023-10-01 13:33:25 -07:00
Linus Torvalds
ec8c298121 Misc fixes: a kerneldoc build warning fix, add SRSO mitigation for
AMD-derived Hygon processors, and fix a SGX kernel crash in the
 page fault handler that can trigger when ksgxd races to reclaim
 the SECS special page, by making the SECS page unswappable.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: a kerneldoc build warning fix, add SRSO mitigation for
  AMD-derived Hygon processors, and fix a SGX kernel crash in the page
  fault handler that can trigger when ksgxd races to reclaim the SECS
  special page, by making the SECS page unswappable"

* tag 'x86-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race
  x86/srso: Add SRSO mitigation for Hygon processors
  x86/kgdb: Fix a kerneldoc warning when build with W=1
2023-10-01 09:50:58 -07:00
Linus Torvalds
3a38c57a87 Misc fixes: work around an AMD microcode bug on certain models,
and fix kexec kernel PMI handlers on AMD systems that get loaded
 on older kernels that have an unexpected register state.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf event fixes from Ingo Molnar:
 "Misc fixes: work around an AMD microcode bug on certain models, and
  fix kexec kernel PMI handlers on AMD systems that get loaded on older
  kernels that have an unexpected register state"

* tag 'perf-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd: Do not WARN() on every IRQ
  perf/x86/amd/core: Fix overflow reset on hotplug
2023-10-01 09:34:53 -07:00
Matthew Wilcox (Oracle)
ce60f27bb6 mm: abstract moving to the next PFN
In order to fix the L1TF vulnerability, x86 can invert the PTE bits for
PROT_NONE VMAs, which means we cannot move from one PTE to the next by
adding 1 to the PFN field of the PTE.  This results in the BUG reported at
[1].

Abstract advancing the PTE to the next PFN through a pte_next_pfn()
function/macro.

Link: https://lkml.kernel.org/r/20230920040958.866520-1-willy@infradead.org
Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: syzbot+55cc72f8cc3a549119df@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000d099fa0604f03351@google.com [1]
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-29 17:20:46 -07:00
Haitao Huang
c6c2adcba5 x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race
The SGX EPC reclaimer (ksgxd) may reclaim the SECS EPC page for an
enclave and set secs.epc_page to NULL. The SECS page is used for EAUG
and ELDU in the SGX page fault handler. However, the NULL check for
secs.epc_page is only done for ELDU, not EAUG before being used.

Fix this by doing the same NULL check and reloading of the SECS page as
needed for both EAUG and ELDU.

The SECS page holds global enclave metadata. It can only be reclaimed
when there are no other enclave pages remaining. At that point,
virtually nothing can be done with the enclave until the SECS page is
paged back in.

An enclave can not run nor generate page faults without a resident SECS
page. But it is still possible for a #PF for a non-SECS page to race
with paging out the SECS page: when the last resident non-SECS page A
triggers a #PF in a non-resident page B, and then page A and the SECS
both are paged out before the #PF on B is handled.

Hitting this bug requires that race triggered with a #PF for EAUG.
Following is a trace when it happens.

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:sgx_encl_eaug_page+0xc7/0x210
Call Trace:
 ? __kmem_cache_alloc_node+0x16a/0x440
 ? xa_load+0x6e/0xa0
 sgx_vma_fault+0x119/0x230
 __do_fault+0x36/0x140
 do_fault+0x12f/0x400
 __handle_mm_fault+0x728/0x1110
 handle_mm_fault+0x105/0x310
 do_user_addr_fault+0x1ee/0x750
 ? __this_cpu_preempt_check+0x13/0x20
 exc_page_fault+0x76/0x180
 asm_exc_page_fault+0x27/0x30

Fixes: 5a90d2c3f5ef ("x86/sgx: Support adding of pages to an initialized enclave")
Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20230728051024.33063-1-haitao.huang%40linux.intel.com
2023-09-28 16:16:40 -07:00
Pu Wen
a5ef7d68ce x86/srso: Add SRSO mitigation for Hygon processors
Add mitigation for the speculative return stack overflow vulnerability
which exists on Hygon processors too.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/tencent_4A14812842F104E93AA722EC939483CEFF05@qq.com
2023-09-28 09:57:07 +02:00
Jim Mattson
73554b29bd KVM: x86/pmu: Synthesize at most one PMI per VM-exit
When the irq_work callback, kvm_pmi_trigger_fn(), is invoked during a
VM-exit that also invokes __kvm_perf_overflow() as a result of
instruction emulation, kvm_pmu_deliver_pmi() will be called twice
before the next VM-entry.

Calling kvm_pmu_deliver_pmi() twice is unlikely to be problematic now that
KVM sets the LVTPC mask bit when delivering a PMI.  But using IRQ work to
trigger the PMI is still broken, albeit very theoretically.

E.g. if the self-IPI to trigger IRQ work is be delayed long enough for the
vCPU to be migrated to a different pCPU, then it's possible for
kvm_pmi_trigger_fn() to race with the kvm_pmu_deliver_pmi() from
KVM_REQ_PMI and still generate two PMIs.

KVM could set the mask bit using an atomic operation, but that'd just be
piling on unnecessary code to workaround what is effectively a hack.  The
*only* reason KVM uses IRQ work is to ensure the PMI is treated as a wake
event, e.g. if the vCPU just executed HLT.

Remove the irq_work callback for synthesizing a PMI, and all of the
logic for invoking it. Instead, to prevent a vcpu from leaving C0 with
a PMI pending, add a check for KVM_REQ_PMI to kvm_vcpu_has_events().

Fixes: 9cd803d496e7 ("KVM: x86: Update vPMCs when retiring instructions")
Signed-off-by: Jim Mattson <jmattson@google.com>
Tested-by: Mingwei Zhang <mizhang@google.com>
Tested-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230925173448.3518223-2-mizhang@google.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-09-25 14:42:52 -07:00
Jim Mattson
a16eb25b09 KVM: x86: Mask LVTPC when handling a PMI
Per the SDM, "When the local APIC handles a performance-monitoring
counters interrupt, it automatically sets the mask flag in the LVT
performance counter register."  Add this behavior to KVM's local APIC
emulation.

Failure to mask the LVTPC entry results in spurious PMIs, e.g. when
running Linux as a guest, PMI handlers that do a "late_ack" spew a large
number of "dazed and confused" spurious NMI warnings.

Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests")
Cc: stable@vger.kernel.org
Signed-off-by: Jim Mattson <jmattson@google.com>
Tested-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230925173448.3518223-3-mizhang@google.com
[sean: massage changelog, correct Fixes]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-09-25 14:40:29 -07:00
Roman Kagan
b29a2acd36 KVM: x86/pmu: Truncate counter value to allowed width on write
Performance counters are defined to have width less than 64 bits.  The
vPMU code maintains the counters in u64 variables but assumes the value
to fit within the defined width.  However, for Intel non-full-width
counters (MSR_IA32_PERFCTRx) the value receieved from the guest is
truncated to 32 bits and then sign-extended to full 64 bits.  If a
negative value is set, it's sign-extended to 64 bits, but then in
kvm_pmu_incr_counter() it's incremented, truncated, and compared to the
previous value for overflow detection.

That previous value is not truncated, so it always evaluates bigger than
the truncated new one, and a PMI is injected.  If the PMI handler writes
a negative counter value itself, the vCPU never quits the PMI loop.

Turns out that Linux PMI handler actually does write the counter with
the value just read with RDPMC, so when no full-width support is exposed
via MSR_IA32_PERF_CAPABILITIES, and the guest initializes the counter to
a negative value, it locks up.

This has been observed in the field, for example, when the guest configures
atop to use perfevents and runs two instances of it simultaneously.

To address the problem, maintain the invariant that the counter value
always fits in the defined bit width, by truncating the received value
in the respective set_msr methods.  For better readability, factor the
out into a helper function, pmc_write_counter(), shared by vmx and svm
parts.

Fixes: 9cd803d496e7 ("KVM: x86: Update vPMCs when retiring instructions")
Cc: stable@vger.kernel.org
Signed-off-by: Roman Kagan <rkagan@amazon.de>
Link: https://lore.kernel.org/all/20230504120042.785651-1-rkagan@amazon.de
Tested-by: Like Xu <likexu@tencent.com>
[sean: tweak changelog, s/set/write in the helper]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-09-25 14:30:44 -07:00
Breno Leitao
599522d9d2 perf/x86/amd: Do not WARN() on every IRQ
Zen 4 systems running buggy microcode can hit a WARN_ON() in the PMI
handler, as shown below, several times while perf runs. A simple
`perf top` run is enough to render the system unusable:

  WARNING: CPU: 18 PID: 20608 at arch/x86/events/amd/core.c:944 amd_pmu_v2_handle_irq+0x1be/0x2b0

This happens because the Performance Counter Global Status Register
(PerfCntGlobalStatus) has one or more bits set which are considered
reserved according to the "AMD64 Architecture Programmer’s Manual,
Volume 2: System Programming, 24593":

  https://www.amd.com/system/files/TechDocs/24593.pdf

To make this less intrusive, warn just once if any reserved bit is set
and prompt the user to update the microcode. Also sanitize the value to
what the code is handling, so that the overflow events continue to be
handled for the number of counters that are known to be sane.

Going forward, the following microcode patch levels are recommended
for Zen 4 processors in order to avoid such issues with reserved bits:

  Family=0x19 Model=0x11 Stepping=0x01: Patch=0x0a10113e
  Family=0x19 Model=0x11 Stepping=0x02: Patch=0x0a10123e
  Family=0x19 Model=0xa0 Stepping=0x01: Patch=0x0aa00116
  Family=0x19 Model=0xa0 Stepping=0x02: Patch=0x0aa00212

Commit f2eb058afc57 ("linux-firmware: Update AMD cpu microcode") from
the linux-firmware tree has binaries that meet the minimum required
patch levels.

  [ sandipan: - add message to prompt users to update microcode
              - rework commit message and call out required microcode levels ]

Fixes: 7685665c390d ("perf/x86/amd/core: Add PerfMonV2 overflow handling")
Reported-by: Jirka Hladky <jhladky@redhat.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/3540f985652f41041e54ee82aa53e7dbd55739ae.1694696888.git.sandipan.das@amd.com/
2023-09-25 11:30:31 +02:00
Linus Torvalds
8a511e7efc ARM:
* Fix EL2 Stage-1 MMIO mappings where a random address was used
 
 * Fix SMCCC function number comparison when the SVE hint is set
 
 RISC-V:
 
 * Fix KVM_GET_REG_LIST API for ISA_EXT registers
 
 * Fix reading ISA_EXT register of a missing extension
 
 * Fix ISA_EXT register handling in get-reg-list test
 
 * Fix filtering of AIA registers in get-reg-list test
 
 x86:
 
 * Fixes for TSC_AUX virtualization
 
 * Stop zapping page tables asynchronously, since we don't
   zap them as often as before
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
"ARM:

   - Fix EL2 Stage-1 MMIO mappings where a random address was used

   - Fix SMCCC function number comparison when the SVE hint is set

  RISC-V:

   - Fix KVM_GET_REG_LIST API for ISA_EXT registers

   - Fix reading ISA_EXT register of a missing extension

   - Fix ISA_EXT register handling in get-reg-list test

   - Fix filtering of AIA registers in get-reg-list test

  x86:

   - Fixes for TSC_AUX virtualization

   - Stop zapping page tables asynchronously, since we don't zap them as
     often as before"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: SVM: Do not use user return MSR support for virtualized TSC_AUX
  KVM: SVM: Fix TSC_AUX virtualization setup
  KVM: SVM: INTERCEPT_RDTSCP is never intercepted anyway
  KVM: x86/mmu: Stop zapping invalidated TDP MMU roots asynchronously
  KVM: x86/mmu: Do not filter address spaces in for_each_tdp_mmu_root_yield_safe()
  KVM: x86/mmu: Open code leaf invalidation from mmu_notifier
  KVM: riscv: selftests: Selectively filter-out AIA registers
  KVM: riscv: selftests: Fix ISA_EXT register handling in get-reg-list
  RISC-V: KVM: Fix riscv_vcpu_get_isa_ext_single() for missing extensions
  RISC-V: KVM: Fix KVM_GET_REG_LIST API for ISA_EXT registers
  KVM: selftests: Assert that vasprintf() is successful
  KVM: arm64: nvhe: Ignore SVE hint in SMCCC function ID
  KVM: arm64: Properly return allocated EL2 VA from hyp_alloc_private_va_range()
2023-09-24 14:14:35 -07:00
Christophe JAILLET
94adf495e7 x86/kgdb: Fix a kerneldoc warning when build with W=1
When compiled with W=1, the following warning is generated:

  arch/x86/kernel/kgdb.c:698: warning: Cannot understand  *
   on line 698 - I thought it was a doc line

Remove the corresponding empty comment line to fix the warning.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/aad659537c1d4ebd86912a6f0be458676c8e69af.1695401178.git.christophe.jaillet@wanadoo.fr
2023-09-24 11:00:13 +02:00
Paolo Bonzini
5804c19b80 KVM/riscv fixes for 6.6, take #1
- Fix KVM_GET_REG_LIST API for ISA_EXT registers
 - Fix reading ISA_EXT register of a missing extension
 - Fix ISA_EXT register handling in get-reg-list test
 - Fix filtering of AIA registers in get-reg-list test
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Merge tag 'kvm-riscv-fixes-6.6-1' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv fixes for 6.6, take #1

- Fix KVM_GET_REG_LIST API for ISA_EXT registers
- Fix reading ISA_EXT register of a missing extension
- Fix ISA_EXT register handling in get-reg-list test
- Fix filtering of AIA registers in get-reg-list test
2023-09-23 05:35:55 -04:00
Tom Lendacky
916e3e5f26 KVM: SVM: Do not use user return MSR support for virtualized TSC_AUX
When the TSC_AUX MSR is virtualized, the TSC_AUX value is swap type "B"
within the VMSA. This means that the guest value is loaded on VMRUN and
the host value is restored from the host save area on #VMEXIT.

Since the value is restored on #VMEXIT, the KVM user return MSR support
for TSC_AUX can be replaced by populating the host save area with the
current host value of TSC_AUX. And, since TSC_AUX is not changed by Linux
post-boot, the host save area can be set once in svm_hardware_enable().
This eliminates the two WRMSR instructions associated with the user return
MSR support.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <d381de38eb0ab6c9c93dda8503b72b72546053d7.1694811272.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-23 05:35:49 -04:00
Tom Lendacky
e0096d01c4 KVM: SVM: Fix TSC_AUX virtualization setup
The checks for virtualizing TSC_AUX occur during the vCPU reset processing
path. However, at the time of initial vCPU reset processing, when the vCPU
is first created, not all of the guest CPUID information has been set. In
this case the RDTSCP and RDPID feature support for the guest is not in
place and so TSC_AUX virtualization is not established.

This continues for each vCPU created for the guest. On the first boot of
an AP, vCPU reset processing is executed as a result of an APIC INIT
event, this time with all of the guest CPUID information set, resulting
in TSC_AUX virtualization being enabled, but only for the APs. The BSP
always sees a TSC_AUX value of 0 which probably went unnoticed because,
at least for Linux, the BSP TSC_AUX value is 0.

Move the TSC_AUX virtualization enablement out of the init_vmcb() path and
into the vcpu_after_set_cpuid() path to allow for proper initialization of
the support after the guest CPUID information has been set.

With the TSC_AUX virtualization support now in the vcpu_set_after_cpuid()
path, the intercepts must be either cleared or set based on the guest
CPUID input.

Fixes: 296d5a17e793 ("KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <4137fbcb9008951ab5f0befa74a0399d2cce809a.1694811272.git.thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-23 05:35:49 -04:00
Paolo Bonzini
e8d93d5d93 KVM: SVM: INTERCEPT_RDTSCP is never intercepted anyway
svm_recalc_instruction_intercepts() is always called at least once
before the vCPU is started, so the setting or clearing of the RDTSCP
intercept can be dropped from the TSC_AUX virtualization support.

Extracted from a patch by Tom Lendacky.

Cc: stable@vger.kernel.org
Fixes: 296d5a17e793 ("KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-23 05:35:49 -04:00
Sean Christopherson
0df9dab891 KVM: x86/mmu: Stop zapping invalidated TDP MMU roots asynchronously
Stop zapping invalidate TDP MMU roots via work queue now that KVM
preserves TDP MMU roots until they are explicitly invalidated.  Zapping
roots asynchronously was effectively a workaround to avoid stalling a vCPU
for an extended during if a vCPU unloaded a root, which at the time
happened whenever the guest toggled CR0.WP (a frequent operation for some
guest kernels).

While a clever hack, zapping roots via an unbound worker had subtle,
unintended consequences on host scheduling, especially when zapping
multiple roots, e.g. as part of a memslot.  Because the work of zapping a
root is no longer bound to the task that initiated the zap, things like
the CPU affinity and priority of the original task get lost.  Losing the
affinity and priority can be especially problematic if unbound workqueues
aren't affined to a small number of CPUs, as zapping multiple roots can
cause KVM to heavily utilize the majority of CPUs in the system, *beyond*
the CPUs KVM is already using to run vCPUs.

When deleting a memslot via KVM_SET_USER_MEMORY_REGION, the async root
zap can result in KVM occupying all logical CPUs for ~8ms, and result in
high priority tasks not being scheduled in in a timely manner.  In v5.15,
which doesn't preserve unloaded roots, the issues were even more noticeable
as KVM would zap roots more frequently and could occupy all CPUs for 50ms+.

Consuming all CPUs for an extended duration can lead to significant jitter
throughout the system, e.g. on ChromeOS with virtio-gpu, deleting memslots
is a semi-frequent operation as memslots are deleted and recreated with
different host virtual addresses to react to host GPU drivers allocating
and freeing GPU blobs.  On ChromeOS, the jitter manifests as audio blips
during games due to the audio server's tasks not getting scheduled in
promptly, despite the tasks having a high realtime priority.

Deleting memslots isn't exactly a fast path and should be avoided when
possible, and ChromeOS is working towards utilizing MAP_FIXED to avoid the
memslot shenanigans, but KVM is squarely in the wrong.  Not to mention
that removing the async zapping eliminates a non-trivial amount of
complexity.

Note, one of the subtle behaviors hidden behind the async zapping is that
KVM would zap invalidated roots only once (ignoring partial zaps from
things like mmu_notifier events).  Preserve this behavior by adding a flag
to identify roots that are scheduled to be zapped versus roots that have
already been zapped but not yet freed.

Add a comment calling out why kvm_tdp_mmu_invalidate_all_roots() can
encounter invalid roots, as it's not at all obvious why zapping
invalidated roots shouldn't simply zap all invalid roots.

Reported-by: Pattara Teerapong <pteerapong@google.com>
Cc: David Stevens <stevensd@google.com>
Cc: Yiwei Zhang<zzyiwei@google.com>
Cc: Paul Hsia <paulhsia@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230916003916.2545000-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-23 05:35:48 -04:00
Paolo Bonzini
441a5dfcd9 KVM: x86/mmu: Do not filter address spaces in for_each_tdp_mmu_root_yield_safe()
All callers except the MMU notifier want to process all address spaces.
Remove the address space ID argument of for_each_tdp_mmu_root_yield_safe()
and switch the MMU notifier to use __for_each_tdp_mmu_root_yield_safe().

Extracted out of a patch by Sean Christopherson <seanjc@google.com>

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-23 05:35:12 -04:00
Linus Torvalds
b61ec8d0f1 Fix the patching ordering between static calls and return thunks.
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Merge tag 'x86_urgent_for_v6.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 rethunk fixes from Borislav Petkov:
 "Fix the patching ordering between static calls and return thunks"

* tag 'x86_urgent_for_v6.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86,static_call: Fix static-call vs return-thunk
  x86/alternatives: Remove faulty optimization
2023-09-22 12:35:56 -07:00
Linus Torvalds
e583bffeb8 Misc x86 fixes:
- Fix a kexec bug,
  - Fix an UML build bug,
  - Fix a handful of SRSO related bugs,
  - Fix a shadow stacks handling bug & robustify related code.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2023-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes from Ingo Molnar:

 - Fix a kexec bug

 - Fix an UML build bug

 - Fix a handful of SRSO related bugs

 - Fix a shadow stacks handling bug & robustify related code

* tag 'x86-urgent-2023-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/shstk: Add warning for shadow stack double unmap
  x86/shstk: Remove useless clone error handling
  x86/shstk: Handle vfork clone failure correctly
  x86/srso: Fix SBPB enablement for spec_rstack_overflow=off
  x86/srso: Don't probe microcode in a guest
  x86/srso: Set CPUID feature bits independently of bug or mitigation status
  x86/srso: Fix srso_show_state() side effect
  x86/asm: Fix build of UML with KASAN
  x86/mm, kexec, ima: Use memblock_free_late() from ima_free_kexec_buffer()
2023-09-22 12:26:42 -07:00
Saurabh Sengar
203a521bd9 x86/hyperv: Add common print prefix "Hyper-V" in hv_init
Add "#define pr_fmt()" in hv_init.c to use "Hyper-V:" as common
print prefix for all pr_*() statements in this file.

Remove the "Hyper-V:" already prefixed in couple of prints.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/1695123361-8877-1-git-send-email-ssengar@linux.microsoft.com
2023-09-22 18:43:09 +00:00
Saurabh Sengar
14058f72cf x86/hyperv: Remove hv_vtl_early_init initcall
There has been cases reported where HYPERV_VTL_MODE is enabled by mistake,
on a non Hyper-V platforms. This causes the hv_vtl_early_init function to
be called in an non Hyper-V/VTL platforms which results the memory
corruption.

Remove the early_initcall for hv_vtl_early_init and call it at the end of
hyperv_init to make sure it is never called in a non Hyper-V platform by
mistake.

Reported-by: Mathias Krause <minipli@grsecurity.net>
Closes: https://lore.kernel.org/lkml/40467722-f4ab-19a5-4989-308225b1f9f0@grsecurity.net/
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Acked-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/1695358720-27681-1-git-send-email-ssengar@linux.microsoft.com
2023-09-22 18:41:29 +00:00