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| author | Maxim Levitsky <mlevitsk@redhat.com> | 2023-07-26 16:59:45 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-07-29 18:05:25 +0300 |
| commit | bf672720e83cf04c007aa11c242229e70985135b (patch) | |
| tree | 94c91773d3963f9041b363b9e1efd4640019de88 /arch/x86 | |
| parent | cff540ebef38303a4cabf4b8bb49317be01b4b0f (diff) | |
| download | linux-bf672720e83cf04c007aa11c242229e70985135b.tar.xz | |
KVM: x86: check the kvm_cpu_get_interrupt result before using it
The code was blindly assuming that kvm_cpu_get_interrupt never returns -1
when there is a pending interrupt.
While this should be true, a bug in KVM can still cause this.
If -1 is returned, the code before this patch was converting it to 0xFF,
and 0xFF interrupt was injected to the guest, which results in an issue
which was hard to debug.
Add WARN_ON_ONCE to catch this case and skip the injection
if this happens again.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20230726135945.260841-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/x86.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a6b9bea62fb8..00b87fcf6da4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10203,9 +10203,13 @@ static int kvm_check_and_inject_events(struct kvm_vcpu *vcpu, if (r < 0) goto out; if (r) { - kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu), false); - static_call(kvm_x86_inject_irq)(vcpu, false); - WARN_ON(static_call(kvm_x86_interrupt_allowed)(vcpu, true) < 0); + int irq = kvm_cpu_get_interrupt(vcpu); + + if (!WARN_ON_ONCE(irq == -1)) { + kvm_queue_interrupt(vcpu, irq, false); + static_call(kvm_x86_inject_irq)(vcpu, false); + WARN_ON(static_call(kvm_x86_interrupt_allowed)(vcpu, true) < 0); + } } if (kvm_cpu_has_injectable_intr(vcpu)) static_call(kvm_x86_enable_irq_window)(vcpu); |