From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 3/3] KVM: MMU: retry #PF for softmmu
Date: Tue, 09 Nov 2010 17:16:50 +0800 [thread overview]
Message-ID: <4CD91182.5010503@cn.fujitsu.com> (raw)
In-Reply-To: <20101109080631.GJ9036@redhat.com>
On 11/09/2010 04:06 PM, Gleb Natapov wrote:
> On Thu, Nov 04, 2010 at 06:36:36PM +0800, Xiao Guangrong wrote:
>> Retry #PF for softmmu only when the current vcpu has the same
>> root shadow page as the time when #PF occurs. it means they
>> have same paging environment.
>>
> Avi had an idea to allocate spte at the fault time, get reference
> to it and populate it on completion instead of prefaulting. How hard
> will it be?
>
Um. if we do it like this, we can't populate it directly, we should:
- hold mmu_lock and walk vcpu's page table to see whether this spte is mapping
in vcpu's page table (since the middle mapping can be zapped during apf is
requesting and shadow page table can be switched)
- the guest page mapping can be modified by other vcpu or other process, we need
re-walk guest page table.
I prefer to the way in this patch since it's very light.
prev parent reply other threads:[~2010-11-09 9:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-04 10:30 [PATCH 1/3] KVM: MMU: fix missing post sync audit Xiao Guangrong
2010-11-04 10:32 ` [PATCH 2/3] KVM: MMU: don not retry #PF for nonpaging guest Xiao Guangrong
2010-11-04 10:35 ` Gleb Natapov
2010-11-05 5:39 ` Xiao Guangrong
2010-11-05 7:45 ` Gleb Natapov
2010-11-05 8:03 ` Xiao Guangrong
2010-11-05 10:31 ` Gleb Natapov
2010-11-08 2:14 ` Xiao Guangrong
2010-11-08 13:52 ` Gleb Natapov
2010-11-08 16:58 ` Xiao Guangrong
2010-11-08 17:01 ` Gleb Natapov
2010-11-09 8:03 ` Gleb Natapov
2010-11-09 8:48 ` Xiao Guangrong
2010-11-09 9:26 ` Gleb Natapov
2010-11-09 9:52 ` Xiao Guangrong
2010-11-09 10:51 ` Gleb Natapov
2010-11-10 2:08 ` Xiao Guangrong
2010-11-04 10:36 ` [PATCH 3/3] KVM: MMU: retry #PF for softmmu Xiao Guangrong
2010-11-09 8:06 ` Gleb Natapov
2010-11-09 9:16 ` Xiao Guangrong [this message]
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