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From: ma.mandourr@gmail.com
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, ma.mandourr@gmail.com
Subject: [PATCH v2 0/3] KVM: nVMX: Don't clobber VM-Entry instruction length on soft INTn exits
Date: Thu, 22 Oct 2026 17:37:00 -0700	[thread overview]
Message-ID: <20261023003703.450577-1-ma.mandourr@gmail.com> (raw)

From: Mahmoud Abumandour <ma.mandourr@gmail.com>

KVM writes the length of a soft INTn that L2 was vectoring at the time of a
nested VM-Exit into vmcs12's VM-Entrty instruction length instead of the VM-Exit
instruction length.

Patch 1 did not exist in v1, but Sashiko pointed out that prepare_vmcs12()
overwrites the VM-exit instruction length that vmcs12_save_pending_event() saves
for soft events.

The selftest patch was written with the help of an LLM (Claude Opus 5.5).

v2:
 - New Patch 1
 - Same Patch 2 from v1 (with commit message changes)
 - Patch 3 now extends nested_exceptions_test instead of adding a new test
   (suggested by Sashiko).

v1: https://lore.kernel.org/all/20261021042603.608292-1-ma.mandourr@gmail.com

Mahmoud Abumandour (3):
  KVM: nVMX: Fill VM-Exit instruction length before saving pending event
  KVM: nVMX: Don't clobber VM-Entry instruction length when saving soft
    INTn
  KVM: selftests: Verify nested VM-Exits while vectoring INT3 and INTn

 arch/x86/kvm/vmx/nested.c                     |  6 ++-
 .../kvm/x86/nested_exceptions_test.c          | 39 +++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)

-- 
2.43.0


             reply	other threads:[~2026-10-23  0:37 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-23  0:37 ma.mandourr [this message]
2026-10-23  0:37 ` [PATCH v2 1/3] KVM: nVMX: Fill VM-Exit instruction length before saving pending event ma.mandourr
2026-10-23  0:37 ` [PATCH v2 2/3] KVM: nVMX: Don't clobber VM-Entry instruction length when saving soft INTn ma.mandourr
2026-10-23  0:37 ` [PATCH v2 3/3] KVM: selftests: Verify nested VM-Exits while vectoring INT3 and INTn ma.mandourr

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