Messages in this thread | | | Subject | Re: [PATCH 09/11] KVM: MMU: simplify mmu_need_write_protect | From | Kai Huang <> | Date | Tue, 15 Dec 2015 16:47:23 +0800 |
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On 12/15/2015 04:43 PM, Kai Huang wrote: > > > On 12/01/2015 02:26 AM, Xiao Guangrong wrote: >> Now, all non-leaf shadow page are page tracked, if gfn is not tracked >> there is no non-leaf shadow page of gfn is existed, we can directly >> make the shadow page of gfn to unsync >> >> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> >> --- >> arch/x86/kvm/mmu.c | 26 ++++++++------------------ >> 1 file changed, 8 insertions(+), 18 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index 5a2ca73..f89e77f 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -2461,41 +2461,31 @@ static void __kvm_unsync_page(struct kvm_vcpu >> *vcpu, struct kvm_mmu_page *sp) >> kvm_mmu_mark_parents_unsync(sp); >> } >> -static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn) >> +static bool kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, >> + bool can_unsync) >> { >> struct kvm_mmu_page *s; >> for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) { >> + if (!can_unsync) >> + return true; > How about moving this right before for_each_gfn_indirect_valid_sp? As > can_unsync is passed as parameter, so there's no point checking it > several times. > > A further thinking is can we move it to mmu_need_write_protect? > Passing can_unsync as parameter to kvm_unsync_pages sounds a little > bit odd. > >> + >> if (s->unsync) >> continue; >> WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL); > How about large page mapping? Such as if guest uses 2M mapping and its > shadow is indirect, does above WARN_ON still meet? As you removed the > PT level check in mmu_need_write_protect. > > Thanks, > -Kai Btw I also think this patch can be merged with patch 6.
Thanks, -Kai >> __kvm_unsync_page(vcpu, s); >> } >> + >> + return false; >> } > >> static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, >> bool can_unsync) >> { >> - struct kvm_mmu_page *s; >> - bool need_unsync = false; >> - >> if (kvm_page_track_check_mode(vcpu, gfn, KVM_PAGE_TRACK_WRITE)) >> return true; >> - for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) { >> - if (!can_unsync) >> - return true; >> - >> - if (s->role.level != PT_PAGE_TABLE_LEVEL) >> - return true; >> - >> - if (!s->unsync) >> - need_unsync = true; >> - } >> - if (need_unsync) >> - kvm_unsync_pages(vcpu, gfn); >> - >> - return false; >> + return kvm_unsync_pages(vcpu, gfn, can_unsync); >> } >> static bool kvm_is_mmio_pfn(pfn_t pfn) > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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