Re: [PATCH] KVM: x86: Check for nested events if there is an injectable interrupt

Wanpeng Li
2014-07-08T09:25:42Z

On Tue, Jul 08, 2014 at 10:00:35AM +0200, Paolo Bonzini wrote:
>Il 08/07/2014 08:56, Jan Kiszka ha scritto:
>>I don't think arch.nmi_pending can flip asynchronously, only in the
>>context of the VCPU thread - in contrast to pending IRQ states.
>
>Right, only nmi_queued is changed from other threads. /me should
>really look at the code instead of going from memory.
>
>>>Jan, what do you think? Can you run Jailhouse through this patch?
>>
>>Jailhouse seems fine with it, and it resolves the lockup of nested KVM
>>here as well.
>
>Thinking more about it, I think this is the right fix. Not setting
>KVM_REQ_EVENT in some cases can be an optimization, but it's not
>necessary. Definitely there are other cases in which KVM_REQ_EVENT
>is set even though no event is pending---most notably during
>emulation of invalid guest state.

Anyway,

Reviewed-by: Wanpeng Li <wanpeng.li@linux.intel.com>

>
>Paolo