linux-kernel - [PATCH v2 0/2] KVM: nSVM: Handle L2 clearing EFER.SVME properly

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Message-ID: <20260209195142.2554532-1-yosry.ahmed@linux.dev>
Date: Mon,  9 Feb 2026 19:51:40 +0000
From: Yosry Ahmed <yosry.ahmed@...ux.dev>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>,
	kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Yosry Ahmed <yosry.ahmed@...ux.dev>
Subject: [PATCH v2 0/2] KVM: nSVM: Handle L2 clearing EFER.SVME properly

Add more graceful handling of L2 clearing EFER.SVME without L1
interception, which is architecturally undefined. Shutdown L1 instead of
running it with corrupted L2 state, and add a test to verify the new
behavior.

I did not CC stable on patch 1 because it's not technically a KVM bug,
but it would be nice to have it backported. Leaving the decision to
Sean.

Yosry Ahmed (2):
  KVM: SVM: Triple fault L1 on unintercepted EFER.SVME clear by L2
  KVM: selftests: Add a test for L2 clearing EFER.SVME without intercept

 arch/x86/kvm/svm/svm.c                        | 11 ++++
 tools/testing/selftests/kvm/Makefile.kvm      |  1 +
 .../kvm/x86/svm_nested_clear_efer_svme.c      | 55 +++++++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/x86/svm_nested_clear_efer_svme.c


base-commit: e944fe2c09f405a2e2d147145c9b470084bc4c9a
-- 
2.53.0.rc2.204.g2597b5adb4-goog