mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-24 11:25:43 +00:00
Code Issues Releases Wiki Activity

KVM: x86: check the kvm_cpu_get_interrupt result before using it

Browse source 
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>
This commit is contained in:
Maxim Levitsky 2023-07-26 16:59:45 +03:00 committed by Paolo Bonzini
parent cff540ebef
commit bf672720e8
1 changed files with 7 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
arch/x86/kvm/x86.c
View file

@ -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);