Re: [PATCH v4 5/6] KVM: MMU: combine guest pte read between walk andpte prefetch

[Marcelo Tosatti]

On Thu, Jul 01, 2010 at 09:55:56PM +0800, Xiao Guangrong wrote:
> Combine guest pte read between guest pte walk and pte prefetch
> 
> Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx>
> ---
>  arch/x86/kvm/paging_tmpl.h |   48 ++++++++++++++++++++++++++++++-------------
>  1 files changed, 33 insertions(+), 15 deletions(-)

Can't do this, it can miss invlpg:

vcpu0			vcpu1
read guest ptes
			modify guest pte
			invlpg
instantiate stale 
guest pte

See how the pte is reread inside fetch with mmu_lock held.

Otherwise the patchset looks fine to me.

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