On 22/11/17 22:34, Radim Krčmář wrote:
2017-11-21 17:30+0200, Liran Alon:
An alternative could have been done to return -EBUSY in this case.
For now, we decided to just silently override exception and warn on
such an attempt.
Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@xxxxxxxxxx>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1490da89de4b..c8cec7c39c1c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3153,12 +3153,25 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
return -EINVAL;
process_nmi(vcpu);
+
+ /*
+ * Warn if userspace is overriding existing
+ * injected exception
+ */
+ WARN_ON_ONCE(vcpu->arch.exception.injected &&
+ events->exception.injected);
I think that overwriting the injected exception/interrupt is a perfectly
valid operation -- userspace could have rolled back the state to a time
of the previous injection.
Syzkaller would complain sooner or later and I don't see it as a useful
printk, so dropping this patch would be preferred,
thanks.
Hmm haven't thought about this use-case. I agree. This patch should be
dropped from series.
Thanks for spotting this.
-Liran
