On Tue, Jan 26, 2021, Ben Gardon wrote: > On Wed, Jan 20, 2021 at 4:56 PM Sean Christopherson <sea...@google.com> wrote: > > > > On Tue, Jan 12, 2021, Ben Gardon wrote: > > > Make the last few changes necessary to enable the TDP MMU to handle page > > > faults in parallel while holding the mmu_lock in read mode. > > > > > > Reviewed-by: Peter Feiner <pfei...@google.com> > > > > > > Signed-off-by: Ben Gardon <bgar...@google.com> > > > --- > > > arch/x86/kvm/mmu/mmu.c | 12 ++++++++++-- > > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > > index 280d7cd6f94b..fa111ceb67d4 100644 > > > --- a/arch/x86/kvm/mmu/mmu.c > > > +++ b/arch/x86/kvm/mmu/mmu.c > > > @@ -3724,7 +3724,12 @@ static int direct_page_fault(struct kvm_vcpu > > > *vcpu, gpa_t gpa, u32 error_code, > > > return r; > > > > > > r = RET_PF_RETRY; > > > - kvm_mmu_lock(vcpu->kvm); > > > + > > > + if (is_tdp_mmu_root(vcpu->kvm, vcpu->arch.mmu->root_hpa)) > > > > Off topic, what do you think about rewriting is_tdp_mmu_root() to be both > > more > > performant and self-documenting as to when is_tdp_mmu_root() != > > kvm->arch.tdp_mmu_enabled? E.g. key off is_guest_mode() and then do a > > thorough > > audit/check when CONFIG_KVM_MMU_AUDIT=y? > > > > #ifdef CONFIG_KVM_MMU_AUDIT > > bool is_tdp_mmu_root(struct kvm *kvm, hpa_t hpa) > > { > > struct kvm_mmu_page *sp; > > > > if (!kvm->arch.tdp_mmu_enabled) > > return false; > > if (WARN_ON(!VALID_PAGE(hpa))) > > return false; > > > > sp = to_shadow_page(hpa); > > if (WARN_ON(!sp)) > > return false; > > > > return sp->tdp_mmu_page && sp->root_count; > > } > > #endif > > > > bool is_tdp_mmu(struct kvm_vcpu *vcpu) > > { > > bool is_tdp_mmu = kvm->arch.tdp_mmu_enabled && !is_guest_mode(vcpu); > > > > #ifdef CONFIG_KVM_MMU_AUDIT > > WARN_ON(is_tdp_mmu != is_tdp_mmu_root(vcpu->kvm, > > vcpu->arch.mmu->root_hpa)); > > #endif > > return is_tdp_mmu; > > } > > Great suggestions. In the interest of keeping this (already enormous) > series small, I'm inclined to make those changes in a future series if > that's alright with you.
Yep, definitely a different series.