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| author | Paolo Bonzini <pbonzini@redhat.com> | 2020-06-08 07:11:47 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-06-08 08:00:57 -0400 |
| commit | fb7333dfd812062d3d51f377e70c1d3a3788472b (patch) | |
| tree | 701379c48f81158a82ed9ece87a500f8ad4681c8 | |
| parent | 75ad6e800217220b8ee63904fb472fd5c3819259 (diff) | |
| download | linux-fb7333dfd812062d3d51f377e70c1d3a3788472b.tar.bz2 | |
KVM: SVM: fix calls to is_intercept
is_intercept takes an INTERCEPT_* constant, not SVM_EXIT_*; because
of this, the compiler was removing the body of the conditionals,
as if is_intercept returned 0.
This unveils a latent bug: when clearing the VINTR intercept,
int_ctl must also be changed in the L1 VMCB (svm->nested.hsave),
just like the intercept itself is also changed in the L1 VMCB.
Otherwise V_IRQ remains set and, due to the VINTR intercept being clear,
we get a spurious injection of a vector 0 interrupt on the next
L2->L1 vmexit.
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 4 |
2 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 8a6db11dcb43..6bceafb19108 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -258,7 +258,7 @@ void sync_nested_vmcb_control(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) && - is_intercept(svm, SVM_EXIT_VINTR)) { + 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 diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 9e333b91ff78..c8f5e87615d5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1378,6 +1378,8 @@ static void svm_clear_vintr(struct vcpu_svm *svm) /* Drop int_ctl fields related to VINTR injection. */ svm->vmcb->control.int_ctl &= mask; if (is_guest_mode(&svm->vcpu)) { + svm->nested.hsave->control.int_ctl &= mask; + WARN_ON((svm->vmcb->control.int_ctl & V_TPR_MASK) != (svm->nested.ctl.int_ctl & V_TPR_MASK)); svm->vmcb->control.int_ctl |= svm->nested.ctl.int_ctl & ~mask; @@ -1999,7 +2001,7 @@ void svm_set_gif(struct vcpu_svm *svm, bool value) */ if (vgif_enabled(svm)) clr_intercept(svm, INTERCEPT_STGI); - if (is_intercept(svm, SVM_EXIT_VINTR)) + if (is_intercept(svm, INTERCEPT_VINTR)) svm_clear_vintr(svm); enable_gif(svm); |