Messages in this thread | | | Date | Tue, 17 Apr 2012 10:41:41 +0300 | From | Avi Kivity <> | Subject | Re: [PATCH v2 10/16] KVM: MMU: fask check whether page is writable |
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On 04/17/2012 06:55 AM, Xiao Guangrong wrote: > On 04/16/2012 07:47 PM, Avi Kivity wrote: > > > On 04/16/2012 01:20 PM, Xiao Guangrong wrote: > >>>> > >>>> It is used to avoid the unnecessary overload > >>> > >>> It's overloading me :( > >>> > >> > >> > >> Sorry. > >> > > > > The trick is to send those in separate patchset so the maintainer > > doesn't notice. > > > > > Thanks for your suggestion, i will pay more attention on it in the > further. > > For this patch, what did you mean of "those"? You mean the whole > rmap.PTE_LIST_WP_BIT (fast check for shadow page table write protection > and host write protection) or just about host_page_write_protect > (for KSM only)?
All of it. Let's start with just modifying sptes concurrently and only later add reading bits from rmap concurrently, if it proves necessary.
> > If we do not have rmap.PTE_LIST_WP_BIT, there may have regression on > shadow mmu. > > Hmm, do i need implement rmap.PTE_LIST_WP_BIT, then fast page fault?
Let's try to measure the effect without rmap.PTE_LIST_WP_BIT. Usually PTE chains for page tables are short so the effect would be small. Of course we can't tell about all guest.
-- error compiling committee.c: too many arguments to function
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