On 11/17/2010 04:24 AM, Marcelo Tosatti wrote: > On Fri, Nov 12, 2010 at 06:30:22PM +0800, Xiao Guangrong wrote: >> We just need flush tlb if overwrite a writable spte with a read-only one >> >> Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx> >> --- >> arch/x86/kvm/mmu.c | 19 +++++++++---------- >> 1 files changed, 9 insertions(+), 10 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index 4b6d54c..1a93ab4 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -2044,6 +2044,15 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, >> if (pte_access & ACC_WRITE_MASK) >> mark_page_dirty(vcpu->kvm, gfn); >> >> + /* >> + * If we overwrite a writable spte with a read-only one, >> + * flush remote TLBs. Otherwise rmap_write_protect will >> + * find a read-only spte, even though the writable spte >> + * might be cached on a CPU's TLB. >> + */ >> + else if (is_writable_pte(*sptep)) >> + ret = 1; >> + > > The return value of set_spte indicates whether the gfn being mapped to > was write protected, not if a TLB flush is necessary. > Yes, i also noticed this and have fixed in the v2 queue, thanks Marcelo! -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
