| Message ID | 20210402121704.3424115-1-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: MMU: protect TDP MMU pages only down to required level | expand |
Hi Paolo, I'm just going to fix this issue, and found that you have done this ;-) Please feel free to add: Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com> Thanks, Keqian On 2021/4/2 20:17, Paolo Bonzini wrote: > When using manual protection of dirty pages, it is not necessary > to protect nested page tables down to the 4K level; instead KVM > can protect only hugepages in order to split them lazily, and > delay write protection at 4K-granularity until KVM_CLEAR_DIRTY_LOG. > This was overlooked in the TDP MMU, so do it there as well. > > Fixes: a6a0b05da9f37 ("kvm: x86/mmu: Support dirty logging for the TDP MMU") > Cc: Ben Gardon <bgardon@google.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > arch/x86/kvm/mmu/mmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index efb41f31e80a..0d92a269c5fa 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -5538,7 +5538,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, > flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, > start_level, KVM_MAX_HUGEPAGE_LEVEL, false); > if (is_tdp_mmu_enabled(kvm)) > - flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K); > + flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); > write_unlock(&kvm->mmu_lock); > > /* >
On Tue, Apr 06, 2021, Keqian Zhu wrote: > Hi Paolo, > > I'm just going to fix this issue, and found that you have done this ;-) Ha, and meanwhile I'm having a serious case of deja vu[1]. It even received a variant of the magic "Queued, thanks"[2]. Doesn't appear in either of the 5.12 pull requests though, must have gotten lost along the way. [1] https://lkml.kernel.org/r/20210213005015.1651772-3-seanjc@google.com [2] https://lkml.kernel.org/r/b5ab72f2-970f-64bd-891c-48f1c303548d@redhat.com > Please feel free to add: > > Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com> > > Thanks, > Keqian > > On 2021/4/2 20:17, Paolo Bonzini wrote: > > When using manual protection of dirty pages, it is not necessary > > to protect nested page tables down to the 4K level; instead KVM > > can protect only hugepages in order to split them lazily, and > > delay write protection at 4K-granularity until KVM_CLEAR_DIRTY_LOG. > > This was overlooked in the TDP MMU, so do it there as well. > > > > Fixes: a6a0b05da9f37 ("kvm: x86/mmu: Support dirty logging for the TDP MMU") > > Cc: Ben Gardon <bgardon@google.com> > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > > --- > > arch/x86/kvm/mmu/mmu.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index efb41f31e80a..0d92a269c5fa 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -5538,7 +5538,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, > > flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, > > start_level, KVM_MAX_HUGEPAGE_LEVEL, false); > > if (is_tdp_mmu_enabled(kvm)) > > - flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K); > > + flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); > > write_unlock(&kvm->mmu_lock); > > > > /* > >
On 2021/4/7 7:38, Sean Christopherson wrote: > On Tue, Apr 06, 2021, Keqian Zhu wrote: >> Hi Paolo, >> >> I'm just going to fix this issue, and found that you have done this ;-) > > Ha, and meanwhile I'm having a serious case of deja vu[1]. It even received a > variant of the magic "Queued, thanks"[2]. Doesn't appear in either of the 5.12 > pull requests though, must have gotten lost along the way. Good job. We should pick them up :) > > [1] https://lkml.kernel.org/r/20210213005015.1651772-3-seanjc@google.com > [2] https://lkml.kernel.org/r/b5ab72f2-970f-64bd-891c-48f1c303548d@redhat.com > >> Please feel free to add: >> >> Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com> >> >> Thanks, >> Keqian >> >> On 2021/4/2 20:17, Paolo Bonzini wrote: >>> When using manual protection of dirty pages, it is not necessary >>> to protect nested page tables down to the 4K level; instead KVM >>> can protect only hugepages in order to split them lazily, and >>> delay write protection at 4K-granularity until KVM_CLEAR_DIRTY_LOG. >>> This was overlooked in the TDP MMU, so do it there as well. >>> >>> Fixes: a6a0b05da9f37 ("kvm: x86/mmu: Support dirty logging for the TDP MMU") >>> Cc: Ben Gardon <bgardon@google.com> >>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> >>> --- >>> arch/x86/kvm/mmu/mmu.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c >>> index efb41f31e80a..0d92a269c5fa 100644 >>> --- a/arch/x86/kvm/mmu/mmu.c >>> +++ b/arch/x86/kvm/mmu/mmu.c >>> @@ -5538,7 +5538,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, >>> flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, >>> start_level, KVM_MAX_HUGEPAGE_LEVEL, false); >>> if (is_tdp_mmu_enabled(kvm)) >>> - flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K); >>> + flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); >>> write_unlock(&kvm->mmu_lock); >>> >>> /* >>> > . >
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index efb41f31e80a..0d92a269c5fa 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5538,7 +5538,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, start_level, KVM_MAX_HUGEPAGE_LEVEL, false); if (is_tdp_mmu_enabled(kvm)) - flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K); + flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level); write_unlock(&kvm->mmu_lock); /*
When using manual protection of dirty pages, it is not necessary to protect nested page tables down to the 4K level; instead KVM can protect only hugepages in order to split them lazily, and delay write protection at 4K-granularity until KVM_CLEAR_DIRTY_LOG. This was overlooked in the TDP MMU, so do it there as well. Fixes: a6a0b05da9f37 ("kvm: x86/mmu: Support dirty logging for the TDP MMU") Cc: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/mmu/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)