diff options
| author |   Santosh Shukla <Santosh.Shukla@amd.com> | 2023-02-27 14:10:07 +0530 |
|---|---|---|
| committer |   Sean Christopherson <seanjc@google.com> | 2023-03-22 12:19:40 -0700 |
| commit | 7334ede457c6f1f7a26344ed25928f63f9a53a8d (patch) | |
| tree | 5a874e7c36695bb1f539d47277a95bcd996f69d6 /arch/x86/kvm/svm/nested.c | |
| parent | KVM: nSVM: Don't sync vmcb02 V_IRQ back to vmcb12 if KVM (L0) is intercepting VINTR (diff) | |
| download | wireguard-linux-7334ede457c6f1f7a26344ed25928f63f9a53a8d.tar.xz wireguard-linux-7334ede457c6f1f7a26344ed25928f63f9a53a8d.zip | |
KVM: nSVM: Disable intercept of VINTR if saved L1 host RFLAGS.IF is 0
Disable intercept of virtual interrupts (used to detect interrupt windows)
if the saved host (L1) RFLAGS.IF is '0', as the effective RFLAGS.IF for L1
interrupts will never be set while L2 is running (L2's RFLAGS.IF doesn't
affect L1 IRQs when virtual interrupts are enabled).
Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lkml.kernel.org/r/Y9hybI65So5X2LFg%40google.com
Signed-off-by: Santosh Shukla <Santosh.Shukla@amd.com>
Link: https://lore.kernel.org/r/20230227084016.3368-3-santosh.shukla@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/svm/nested.c')
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index a77055d96e31..a0a525758ed9 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -139,13 +139,18 @@ void recalc_intercepts(struct vcpu_svm *svm) if (g->int_ctl & V_INTR_MASKING_MASK) { /* - * Once running L2 with HF_VINTR_MASK, EFLAGS.IF and CR8 - * does not affect any interrupt we may want to inject; - * therefore, writes to CR8 are irrelevant to L0, as are - * interrupt window vmexits. + * If L2 is active and V_INTR_MASKING is enabled in vmcb12, + * disable intercept of CR8 writes as L2's CR8 does not affect + * any interrupt KVM may want to inject. + * + * Similarly, disable intercept of virtual interrupts (used to + * detect interrupt windows) if the saved RFLAGS.IF is '0', as + * the effective RFLAGS.IF for L1 interrupts will never be set + * while L2 is running (L2's RFLAGS.IF doesn't affect L1 IRQs). */ vmcb_clr_intercept(c, INTERCEPT_CR8_WRITE); - vmcb_clr_intercept(c, INTERCEPT_VINTR); + if (!(svm->vmcb01.ptr->save.rflags & X86_EFLAGS_IF)) + vmcb_clr_intercept(c, INTERCEPT_VINTR); } /* |