<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch, branch v7.0-rc6</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2026-03-29T18:58:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-29T18:58:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ac354b5cb04d2077c3821a6cbfbc7981ad45f84a'/>
<id>ac354b5cb04d2077c3821a6cbfbc7981ad45f84a</id>
<content type='text'>
Pull kvm fixes from Paolo Bonzini:
 "s390:

   - Lots of small and not-so-small fixes for the newly rewritten gmap,
     mostly affecting the handling of nested guests.

  x86:

   - Fix an issue with shadow paging, which causes KVM to install an
     MMIO PTE in the shadow page tables without first zapping a non-MMIO
     SPTE if KVM didn't see the write that modified the shadowed guest
     PTE.

     While commit a54aa15c6bda3 ("KVM: x86/mmu: Handle MMIO SPTEs
     directly in mmu_set_spte()") was right about it being impossible to
     miss such a write if it was coming from the guest, it failed to
     account for writes to guest memory that are outside the scope of
     KVM: if userspace modifies the guest PTE, and then the guest hits a
     relevant page fault, KVM will get confused"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE
  KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE
  KVM: s390: Fix KVM_S390_VCPU_FAULT ioctl
  KVM: s390: vsie: Fix guest page tables protection
  KVM: s390: vsie: Fix unshadowing while shadowing
  KVM: s390: vsie: Fix refcount overflow for shadow gmaps
  KVM: s390: vsie: Fix nested guest memory shadowing
  KVM: s390: Correctly handle guest mappings without struct page
  KVM: s390: Fix gmap_link()
  KVM: s390: vsie: Fix check for pre-existing shadow mapping
  KVM: s390: Remove non-atomic dat_crstep_xchg()
  KVM: s390: vsie: Fix dat_split_ste()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kvm fixes from Paolo Bonzini:
 "s390:

   - Lots of small and not-so-small fixes for the newly rewritten gmap,
     mostly affecting the handling of nested guests.

  x86:

   - Fix an issue with shadow paging, which causes KVM to install an
     MMIO PTE in the shadow page tables without first zapping a non-MMIO
     SPTE if KVM didn't see the write that modified the shadowed guest
     PTE.

     While commit a54aa15c6bda3 ("KVM: x86/mmu: Handle MMIO SPTEs
     directly in mmu_set_spte()") was right about it being impossible to
     miss such a write if it was coming from the guest, it failed to
     account for writes to guest memory that are outside the scope of
     KVM: if userspace modifies the guest PTE, and then the guest hits a
     relevant page fault, KVM will get confused"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE
  KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE
  KVM: s390: Fix KVM_S390_VCPU_FAULT ioctl
  KVM: s390: vsie: Fix guest page tables protection
  KVM: s390: vsie: Fix unshadowing while shadowing
  KVM: s390: vsie: Fix refcount overflow for shadow gmaps
  KVM: s390: vsie: Fix nested guest memory shadowing
  KVM: s390: Correctly handle guest mappings without struct page
  KVM: s390: Fix gmap_link()
  KVM: s390: vsie: Fix check for pre-existing shadow mapping
  KVM: s390: Remove non-atomic dat_crstep_xchg()
  KVM: s390: vsie: Fix dat_split_ste()
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-03-29T17:04:37+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-29T17:04:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f242ac4a09443c6e2e0ec03d7e2a21b00cbb3907'/>
<id>f242ac4a09443c6e2e0ec03d7e2a21b00cbb3907</id>
<content type='text'>
Pull x86 fixes from Ingo Molnar:

 - Fix an early boot crash in AMD SEV-SNP guests, caused by incorrect
   FSGSBASE init ordering (Nikunj A Dadhania)

 - Remove X86_CR4_FRED from the CR4 pinned bits mask, to fix a race
   window during the bootup of SEV-{ES,SNP} or TDX guests, which can
   crash them if they trigger exceptions in that window (Borislav
   Petkov)

 - Fix early boot failures on SEV-ES/SNP guests, due to incorrect early
   GHCB access (Nikunj A Dadhania)

 - Add clarifying comment to the CRn pinning logic, to avoid future
   confusion &amp; bugs (Peter Zijlstra)

* tag 'x86-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add comment clarifying CRn pinning
  x86/fred: Fix early boot failures on SEV-ES/SNP guests
  x86/cpu: Remove X86_CR4_FRED from the CR4 pinned bits mask
  x86/cpu: Enable FSGSBASE early in cpu_init_exception_handling()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Ingo Molnar:

 - Fix an early boot crash in AMD SEV-SNP guests, caused by incorrect
   FSGSBASE init ordering (Nikunj A Dadhania)

 - Remove X86_CR4_FRED from the CR4 pinned bits mask, to fix a race
   window during the bootup of SEV-{ES,SNP} or TDX guests, which can
   crash them if they trigger exceptions in that window (Borislav
   Petkov)

 - Fix early boot failures on SEV-ES/SNP guests, due to incorrect early
   GHCB access (Nikunj A Dadhania)

 - Add clarifying comment to the CRn pinning logic, to avoid future
   confusion &amp; bugs (Peter Zijlstra)

* tag 'x86-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add comment clarifying CRn pinning
  x86/fred: Fix early boot failures on SEV-ES/SNP guests
  x86/cpu: Remove X86_CR4_FRED from the CR4 pinned bits mask
  x86/cpu: Enable FSGSBASE early in cpu_init_exception_handling()
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux</title>
<updated>2026-03-28T16:50:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-28T16:50:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e522b75c44f580ba8a58e8d9f263643c7936ddeb'/>
<id>e522b75c44f580ba8a58e8d9f263643c7936ddeb</id>
<content type='text'>
Pull s390 fixes from Vasily Gorbik:

 - Add array_index_nospec() to syscall dispatch table lookup to prevent
   limited speculative out-of-bounds access with user-controlled syscall
   number

 - Mark array_index_mask_nospec() __always_inline since GCC may emit an
   out-of-line call instead of the inline data dependency sequence the
   mitigation relies on

 - Clear r12 on kernel entry to prevent potential speculative use of
   user value in system_call, ext/io/mcck interrupt handlers

* tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/entry: Scrub r12 register on kernel entry
  s390/syscalls: Add spectre boundary for syscall dispatch table
  s390/barrier: Make array_index_mask_nospec() __always_inline
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull s390 fixes from Vasily Gorbik:

 - Add array_index_nospec() to syscall dispatch table lookup to prevent
   limited speculative out-of-bounds access with user-controlled syscall
   number

 - Mark array_index_mask_nospec() __always_inline since GCC may emit an
   out-of-line call instead of the inline data dependency sequence the
   mitigation relies on

 - Clear r12 on kernel entry to prevent potential speculative use of
   user value in system_call, ext/io/mcck interrupt handlers

* tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/entry: Scrub r12 register on kernel entry
  s390/syscalls: Add spectre boundary for syscall dispatch table
  s390/barrier: Make array_index_mask_nospec() __always_inline
</pre>
</div>
</content>
</entry>
<entry>
<title>s390/entry: Scrub r12 register on kernel entry</title>
<updated>2026-03-27T23:43:39+00:00</updated>
<author>
<name>Vasily Gorbik</name>
<email>gor@linux.ibm.com</email>
</author>
<published>2026-03-26T18:50:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0738d395aab8fae3b5a3ad3fc640630c91693c27'/>
<id>0738d395aab8fae3b5a3ad3fc640630c91693c27</id>
<content type='text'>
Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"),
all entry handlers loaded r12 with the current task pointer
(lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That
commit removed TIF_ISOLATE_BP, dropping both the branch prediction
macros and the r12 load, but did not add r12 to the register clearing
sequence.

Add the missing xgr %r12,%r12 to make the register scrub consistent
across all entry points.

Fixes: f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"),
all entry handlers loaded r12 with the current task pointer
(lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That
commit removed TIF_ISOLATE_BP, dropping both the branch prediction
macros and the r12 load, but did not add r12 to the register clearing
sequence.

Add the missing xgr %r12,%r12 to make the register scrub consistent
across all entry points.

Fixes: f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>s390/syscalls: Add spectre boundary for syscall dispatch table</title>
<updated>2026-03-27T23:43:39+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2026-03-24T16:34:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=48b8814e25d073dd84daf990a879a820bad2bcbd'/>
<id>48b8814e25d073dd84daf990a879a820bad2bcbd</id>
<content type='text'>
The s390 syscall number is directly controlled by userspace, but does
not have an array_index_nospec() boundary to prevent access past the
syscall function pointer tables.

Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Fixes: 56e62a737028 ("s390: convert to generic entry")
Cc: stable@kernel.org
Assisted-by: gkh_clanker_2000
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/2026032404-sterling-swoosh-43e6@gregkh
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The s390 syscall number is directly controlled by userspace, but does
not have an array_index_nospec() boundary to prevent access past the
syscall function pointer tables.

Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Fixes: 56e62a737028 ("s390: convert to generic entry")
Cc: stable@kernel.org
Assisted-by: gkh_clanker_2000
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/2026032404-sterling-swoosh-43e6@gregkh
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>s390/barrier: Make array_index_mask_nospec() __always_inline</title>
<updated>2026-03-27T23:43:24+00:00</updated>
<author>
<name>Vasily Gorbik</name>
<email>gor@linux.ibm.com</email>
</author>
<published>2026-03-26T13:38:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c5c0a268b38adffbb2e70e6957017537ff54c157'/>
<id>c5c0a268b38adffbb2e70e6957017537ff54c157</id>
<content type='text'>
Mark array_index_mask_nospec() as __always_inline to guarantee the
mitigation is emitted inline regardless of compiler inlining decisions.

Fixes: e2dd833389cc ("s390: add optimized array_index_mask_nospec")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Mark array_index_mask_nospec() as __always_inline to guarantee the
mitigation is emitted inline regardless of compiler inlining decisions.

Fixes: e2dd833389cc ("s390: add optimized array_index_mask_nospec")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'efi-fixes-for-v7.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi</title>
<updated>2026-03-27T22:55:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-27T22:55:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=56bea424158f6b99a452ab9410092d72b03f8545'/>
<id>56bea424158f6b99a452ab9410092d72b03f8545</id>
<content type='text'>
Pull EFI fix from Ard Biesheuvel:
 "Fix a potential buffer overrun issue introduced by the previous fix
  for EFI boot services region reservations on x86"

* tag 'efi-fixes-for-v7.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  x86/efi: efi_unmap_boot_services: fix calculation of ranges_to_free size
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull EFI fix from Ard Biesheuvel:
 "Fix a potential buffer overrun issue introduced by the previous fix
  for EFI boot services region reservations on x86"

* tag 'efi-fixes-for-v7.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  x86/efi: efi_unmap_boot_services: fix calculation of ranges_to_free size
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'loongarch-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson</title>
<updated>2026-03-27T22:39:41+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-27T22:39:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a361474ba3b3c6bdca7bad72dfd2ffb4f11e8e1d'/>
<id>a361474ba3b3c6bdca7bad72dfd2ffb4f11e8e1d</id>
<content type='text'>
Pull LoongArch fixes from Huacai Chen:
 "Fix missing NULL checks for kstrdup(), workaround LS2K/LS7A GPU
  DMA hang bug, emit GNU_EH_FRAME for vDSO correctly, and fix some
  KVM-related bugs"

* tag 'loongarch-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Fix base address calculation in kvm_eiointc_regs_access()
  LoongArch: KVM: Handle the case that EIOINTC's coremap is empty
  LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
  LoongArch: vDSO: Emit GNU_EH_FRAME correctly
  LoongArch: Workaround LS2K/LS7A GPU DMA hang bug
  LoongArch: Fix missing NULL checks for kstrdup()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull LoongArch fixes from Huacai Chen:
 "Fix missing NULL checks for kstrdup(), workaround LS2K/LS7A GPU
  DMA hang bug, emit GNU_EH_FRAME for vDSO correctly, and fix some
  KVM-related bugs"

* tag 'loongarch-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Fix base address calculation in kvm_eiointc_regs_access()
  LoongArch: KVM: Handle the case that EIOINTC's coremap is empty
  LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
  LoongArch: vDSO: Emit GNU_EH_FRAME correctly
  LoongArch: Workaround LS2K/LS7A GPU DMA hang bug
  LoongArch: Fix missing NULL checks for kstrdup()
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE</title>
<updated>2026-03-27T21:33:33+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2026-03-06T01:42:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=df83746075778958954aa0460cca55f4b3fc9c02'/>
<id>df83746075778958954aa0460cca55f4b3fc9c02</id>
<content type='text'>
Adjust KVM's sanity check against overwriting a shadow-present SPTE with a
another SPTE with a different target PFN to only apply to direct MMUs,
i.e. only to MMUs without shadowed gPTEs.  While it's impossible for KVM
to overwrite a shadow-present SPTE in response to a guest write, writes
from outside the scope of KVM, e.g. from host userspace, aren't detected
by KVM's write tracking and so can break KVM's shadow paging rules.

  ------------[ cut here ]------------
  pfn != spte_to_pfn(*sptep)
  WARNING: arch/x86/kvm/mmu/mmu.c:3069 at mmu_set_spte+0x1e4/0x440 [kvm], CPU#0: vmx_ept_stale_r/872
  Modules linked in: kvm_intel kvm irqbypass
  CPU: 0 UID: 1000 PID: 872 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:mmu_set_spte+0x1e4/0x440 [kvm]
  Call Trace:
   &lt;TASK&gt;
   ept_page_fault+0x535/0x7f0 [kvm]
   kvm_mmu_do_page_fault+0xee/0x1f0 [kvm]
   kvm_mmu_page_fault+0x8d/0x620 [kvm]
   vmx_handle_exit+0x18c/0x5a0 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm]
   kvm_vcpu_ioctl+0x2d5/0x980 [kvm]
   __x64_sys_ioctl+0x8a/0xd0
   do_syscall_64+0xb5/0x730
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
   &lt;/TASK&gt;
  ---[ end trace 0000000000000000 ]---

Fixes: 11d45175111d ("KVM: x86/mmu: Warn if PFN changes on shadow-present SPTE in shadow MMU")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Adjust KVM's sanity check against overwriting a shadow-present SPTE with a
another SPTE with a different target PFN to only apply to direct MMUs,
i.e. only to MMUs without shadowed gPTEs.  While it's impossible for KVM
to overwrite a shadow-present SPTE in response to a guest write, writes
from outside the scope of KVM, e.g. from host userspace, aren't detected
by KVM's write tracking and so can break KVM's shadow paging rules.

  ------------[ cut here ]------------
  pfn != spte_to_pfn(*sptep)
  WARNING: arch/x86/kvm/mmu/mmu.c:3069 at mmu_set_spte+0x1e4/0x440 [kvm], CPU#0: vmx_ept_stale_r/872
  Modules linked in: kvm_intel kvm irqbypass
  CPU: 0 UID: 1000 PID: 872 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:mmu_set_spte+0x1e4/0x440 [kvm]
  Call Trace:
   &lt;TASK&gt;
   ept_page_fault+0x535/0x7f0 [kvm]
   kvm_mmu_do_page_fault+0xee/0x1f0 [kvm]
   kvm_mmu_page_fault+0x8d/0x620 [kvm]
   vmx_handle_exit+0x18c/0x5a0 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm]
   kvm_vcpu_ioctl+0x2d5/0x980 [kvm]
   __x64_sys_ioctl+0x8a/0xd0
   do_syscall_64+0xb5/0x730
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
   &lt;/TASK&gt;
  ---[ end trace 0000000000000000 ]---

Fixes: 11d45175111d ("KVM: x86/mmu: Warn if PFN changes on shadow-present SPTE in shadow MMU")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86/mmu: Drop/zap existing present SPTE even when creating an MMIO SPTE</title>
<updated>2026-03-27T21:33:33+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2026-03-06T01:28:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aad885e774966e97b675dfe928da164214a71605'/>
<id>aad885e774966e97b675dfe928da164214a71605</id>
<content type='text'>
When installing an emulated MMIO SPTE, do so *after* dropping/zapping the
existing SPTE (if it's shadow-present).  While commit a54aa15c6bda3 was
right about it being impossible to convert a shadow-present SPTE to an
MMIO SPTE due to a _guest_ write, it failed to account for writes to guest
memory that are outside the scope of KVM.

E.g. if host userspace modifies a shadowed gPTE to switch from a memslot
to emulted MMIO and then the guest hits a relevant page fault, KVM will
install the MMIO SPTE without first zapping the shadow-present SPTE.

  ------------[ cut here ]------------
  is_shadow_present_pte(*sptep)
  WARNING: arch/x86/kvm/mmu/mmu.c:484 at mark_mmio_spte+0xb2/0xc0 [kvm], CPU#0: vmx_ept_stale_r/4292
  Modules linked in: kvm_intel kvm irqbypass
  CPU: 0 UID: 1000 PID: 4292 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:mark_mmio_spte+0xb2/0xc0 [kvm]
  Call Trace:
   &lt;TASK&gt;
   mmu_set_spte+0x237/0x440 [kvm]
   ept_page_fault+0x535/0x7f0 [kvm]
   kvm_mmu_do_page_fault+0xee/0x1f0 [kvm]
   kvm_mmu_page_fault+0x8d/0x620 [kvm]
   vmx_handle_exit+0x18c/0x5a0 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm]
   kvm_vcpu_ioctl+0x2d5/0x980 [kvm]
   __x64_sys_ioctl+0x8a/0xd0
   do_syscall_64+0xb5/0x730
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
  RIP: 0033:0x47fa3f
   &lt;/TASK&gt;
  ---[ end trace 0000000000000000 ]---

Reported-by: Alexander Bulekov &lt;bkov@amazon.com&gt;
Debugged-by: Alexander Bulekov &lt;bkov@amazon.com&gt;
Suggested-by: Fred Griffoul &lt;fgriffo@amazon.co.uk&gt;
Fixes: a54aa15c6bda3 ("KVM: x86/mmu: Handle MMIO SPTEs directly in mmu_set_spte()")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When installing an emulated MMIO SPTE, do so *after* dropping/zapping the
existing SPTE (if it's shadow-present).  While commit a54aa15c6bda3 was
right about it being impossible to convert a shadow-present SPTE to an
MMIO SPTE due to a _guest_ write, it failed to account for writes to guest
memory that are outside the scope of KVM.

E.g. if host userspace modifies a shadowed gPTE to switch from a memslot
to emulted MMIO and then the guest hits a relevant page fault, KVM will
install the MMIO SPTE without first zapping the shadow-present SPTE.

  ------------[ cut here ]------------
  is_shadow_present_pte(*sptep)
  WARNING: arch/x86/kvm/mmu/mmu.c:484 at mark_mmio_spte+0xb2/0xc0 [kvm], CPU#0: vmx_ept_stale_r/4292
  Modules linked in: kvm_intel kvm irqbypass
  CPU: 0 UID: 1000 PID: 4292 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:mark_mmio_spte+0xb2/0xc0 [kvm]
  Call Trace:
   &lt;TASK&gt;
   mmu_set_spte+0x237/0x440 [kvm]
   ept_page_fault+0x535/0x7f0 [kvm]
   kvm_mmu_do_page_fault+0xee/0x1f0 [kvm]
   kvm_mmu_page_fault+0x8d/0x620 [kvm]
   vmx_handle_exit+0x18c/0x5a0 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm]
   kvm_vcpu_ioctl+0x2d5/0x980 [kvm]
   __x64_sys_ioctl+0x8a/0xd0
   do_syscall_64+0xb5/0x730
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
  RIP: 0033:0x47fa3f
   &lt;/TASK&gt;
  ---[ end trace 0000000000000000 ]---

Reported-by: Alexander Bulekov &lt;bkov@amazon.com&gt;
Debugged-by: Alexander Bulekov &lt;bkov@amazon.com&gt;
Suggested-by: Fred Griffoul &lt;fgriffo@amazon.co.uk&gt;
Fixes: a54aa15c6bda3 ("KVM: x86/mmu: Handle MMIO SPTEs directly in mmu_set_spte()")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
