Date: Tue, 8 Jul 2014 17:26:28 +0800
From: Wanpeng Li <wanpeng.li@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, Bandan Das <bsd@redhat.com>,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Gleb Natapov <gleb@kernel.org>
Subject: Re: [PATCH] KVM: x86: Check for nested events if there is an
 injectable interrupt
Message-ID: <20140708092628.GA19860@kernel>
Reply-To: Wanpeng Li <wanpeng.li@linux.intel.com>
References: <jpgd2dgfp5s.fsf@redhat.com>
 <53BB86C2.9040805@redhat.com>
 <53BB9638.6040803@siemens.com>
 <53BBA523.4080006@redhat.com>
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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
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