From: Santosh Shukla <Santosh.Shukla@xxxxxxx> Don't sync vmcb02 V_IRQ back to vmcb12 if KVM (L0) is intercepting virtual interrupts in order to request an interrupt window, as KVM has usurped vmcb02's int_ctl. If an interrupt window opens before the next VM-Exit, svm_clear_vintr() will restore vmcb12's int_ctl. If no window opens, V_IRQ will be correctly preserved in vmcb12's int_ctl (because it was never recognized while L2 was running). Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Santosh Shukla <Santosh.Shukla@xxxxxxx> --- v4: https://lore.kernel.org/all/Y9hybI65So5X2LFg@xxxxxxxxxx/ suggested by Sean. arch/x86/kvm/svm/nested.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 05d38944a6c0..fbade158d368 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -416,18 +416,17 @@ void nested_sync_control_from_vmcb02(struct vcpu_svm *svm) /* Only a few fields of int_ctl are written by the processor. */ mask = V_IRQ_MASK | V_TPR_MASK; - if (!(svm->nested.ctl.int_ctl & V_INTR_MASKING_MASK) && - svm_is_intercept(svm, INTERCEPT_VINTR)) { - /* - * In order to request an interrupt window, L0 is usurping - * svm->vmcb->control.int_ctl and possibly setting V_IRQ - * even if it was clear in L1's VMCB. Restoring it would be - * wrong. However, in this case V_IRQ will remain true until - * interrupt_window_interception calls svm_clear_vintr and - * restores int_ctl. We can just leave it aside. - */ + /* + * Don't sync vmcb02 V_IRQ back to vmcb12 if KVM (L0) is intercepting + * virtual interrupts in order to request an interrupt window, as KVM + * has usurped vmcb02's int_ctl. If an interrupt window opens before + * the next VM-Exit, svm_clear_vintr() will restore vmcb12's int_ctl. + * If no window opens, V_IRQ will be correctly preserved in vmcb12's + * int_ctl (because it was never recognized while L2 was running). + */ + if (svm_is_intercept(svm, INTERCEPT_VINTR) && + !test_bit(INTERCEPT_VINTR, (unsigned long *)svm->nested.ctl.intercepts)) mask &= ~V_IRQ_MASK; - } if (nested_vgif_enabled(svm)) mask |= V_GIF_MASK; -- 2.25.1
