On 06/21/2011 12:28 AM, Marcelo Tosatti wrote: > On Tue, Jun 07, 2011 at 08:59:25PM +0800, Xiao Guangrong wrote: >> Set slot bitmap only if the spte is present >> >> Signed-off-by: Xiao Guangrong <[email protected]> >> --- >> arch/x86/kvm/mmu.c | 15 +++++++-------- >> 1 files changed, 7 insertions(+), 8 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index cda666a..125f78d 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -743,9 +743,6 @@ static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, >> gfn_t gfn) >> struct kvm_mmu_page *sp; >> unsigned long *rmapp; >> >> - if (!is_rmap_spte(*spte)) >> - return 0; >> - > > Not sure if this is safe, what if the spte is set as nonpresent but > rmap not removed?
It can not happen, since when we set the spte as nonpresent, we always use drop_spte to remove the rmap, we also do it in set_spte() > > BTW i don't see what patch 1 and this have to do with the goal > of the series. > > There are the preparing work for mmio page fault: - Patch 1 fix the bug in walking shadow page, so we can safely use it to lockless-ly walk shadow page - Patch 2 can avoid add rmap for the mmio spte :-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
