From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong.eric@gmail.com>
Subject: Re: [PATCH v2 02/15] KVM: MMU: properly check last spte in fast_page_fault()
Date: Thu, 3 Oct 2013 14:16:49 +0800
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Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>, gleb@redhat.com,
	avi.kivity@gmail.com, pbonzini@redhat.com,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org
To: Marcelo Tosatti <mtosatti@redhat.com>
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On Oct 1, 2013, at 5:23 AM, Marcelo Tosatti <mtosatti@redhat.com> wrote:

>> 
> 
> Unrelated to this patch:
> 
> If vcpu->mode = OUTSIDE_GUEST_MODE, no IPI is sent
> by kvm_flush_remote_tlbs.

Yes.

> 
> So how is this supposed to work again?
> 
>        /*
>         * Wait for all vcpus to exit guest mode and/or lockless shadow
>         * page table walks.
>         */

On the lockless walking path, we change the vcpu->mode to
READING_SHADOW_PAGE_TABLES, so that IPI is needed.
Or i missed your question?


>        kvm_flush_remote_tlbs(kvm);
> 
> Patch looks fine.

Thank you, Marcelo!