From: Sean Christopherson Date: Wed, 8 Jan 2020 20:24:42 +0000 (-0800) Subject: KVM: x86/mmu: Drop level optimization from fast_page_fault() X-Git-Tag: v5.15~4592^2~12 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f9fa2509e5ca8229b4baca295865b542803bf25d;p=platform%2Fkernel%2Flinux-starfive.git KVM: x86/mmu: Drop level optimization from fast_page_fault() Remove fast_page_fault()'s optimization to stop the shadow walk if the iterator level drops below the intended map level. The intended map level is only acccurate for HugeTLB mappings (THP mappings are detected after fast_page_fault()), i.e. it's not required for correctness, and a future patch will also move HugeTLB mapping detection to after fast_page_fault(). Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 3acaadb..17645c2 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3586,7 +3586,7 @@ static bool is_access_allowed(u32 fault_err_code, u64 spte) * - true: let the vcpu to access on the same address again. * - false: let the real page fault path to fix it. */ -static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, int level, +static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u32 error_code) { struct kvm_shadow_walk_iterator iterator; @@ -3604,8 +3604,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, int level, u64 new_spte; for_each_shadow_entry_lockless(vcpu, cr2_or_gpa, iterator, spte) - if (!is_shadow_present_pte(spte) || - iterator.level < level) + if (!is_shadow_present_pte(spte)) break; sp = page_header(__pa(iterator.sptep)); @@ -4218,7 +4217,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (level > PT_PAGE_TABLE_LEVEL) gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); - if (fast_page_fault(vcpu, gpa, level, error_code)) + if (fast_page_fault(vcpu, gpa, error_code)) return RET_PF_RETRY; mmu_seq = vcpu->kvm->mmu_notifier_seq;