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| author | Yosry Ahmed <yosry@kernel.org> | 2026-03-03 03:33:55 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-03-05 03:08:43 +0300 |
| commit | b53ab5167a81537777ac780bbd93d32613aa3bda (patch) | |
| tree | 7cc4b2a56a655b0e741f8cb0c19b6cd3f6cd5ac0 | |
| parent | d99df02ff427f461102230f9c5b90a6c64ee8e23 (diff) | |
| download | linux-b53ab5167a81537777ac780bbd93d32613aa3bda.tar.xz | |
KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12
svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB.
However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and
clearing clean bits in vmcb12 is not architecturally defined.
Move vmcb_mark_dirty() to callers and drop it for vmcb12.
This also facilitates incoming refactoring that does not pass the entire
VMCB to svm_copy_lbrs().
Fixes: d20c796ca370 ("KVM: x86: nSVM: implement nested LBR virtualization")
Cc: stable@vger.kernel.org
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260303003421.2185681-2-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 7 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 2 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 3e2841598a36..0a35c815f4d2 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -715,6 +715,7 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12 } else { svm_copy_lbrs(vmcb02, vmcb01); } + vmcb_mark_dirty(vmcb02, VMCB_LBR); svm_update_lbrv(&svm->vcpu); } @@ -1231,10 +1232,12 @@ int nested_svm_vmexit(struct vcpu_svm *svm) kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) && - (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) + (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) { svm_copy_lbrs(vmcb12, vmcb02); - else + } else { svm_copy_lbrs(vmcb01, vmcb02); + vmcb_mark_dirty(vmcb01, VMCB_LBR); + } svm_update_lbrv(vcpu); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 543f9f3f966e..9b4f5a46d550 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -848,8 +848,6 @@ void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb) to_vmcb->save.br_to = from_vmcb->save.br_to; to_vmcb->save.last_excp_from = from_vmcb->save.last_excp_from; to_vmcb->save.last_excp_to = from_vmcb->save.last_excp_to; - - vmcb_mark_dirty(to_vmcb, VMCB_LBR); } static void __svm_enable_lbrv(struct kvm_vcpu *vcpu) |