From 479a1efc8119d8699cca73d00625b28003d0a1f8 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 22 Jun 2021 10:56:57 -0700 Subject: [PATCH] KVM: x86/mmu: Drop the intermediate "transient" __kvm_sync_page() Nove the kvm_unlink_unsync_page() call out of kvm_sync_page() and into it's sole caller, and fold __kvm_sync_page() into kvm_sync_page() since the latter becomes a pure pass-through. There really should be no reason for code to do a complete sync of a shadow page outside of the full kvm_mmu_sync_roots(), e.g. the one use case that creeped in turned out to be flawed and counter-productive. Drop the stale comment about @sp->gfn needing to be write-protected, as it directly contradicts the kvm_mmu_get_page() usage. No functional change intended. Signed-off-by: Sean Christopherson Message-Id: <20210622175739.3610207-13-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 726e5b171543..92b7ab1a0a77 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1780,9 +1780,8 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm, &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else -/* @sp->gfn should be write-protected at the call site */ -static bool __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, - struct list_head *invalid_list) +static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, + struct list_head *invalid_list) { if (vcpu->arch.mmu->sync_page(vcpu, sp) == 0) { kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); @@ -1830,13 +1829,6 @@ static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); } -static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, - struct list_head *invalid_list) -{ - kvm_unlink_unsync_page(vcpu->kvm, sp); - return __kvm_sync_page(vcpu, sp, invalid_list); -} - struct mmu_page_path { struct kvm_mmu_page *parent[PT64_ROOT_MAX_LEVEL]; unsigned int idx[PT64_ROOT_MAX_LEVEL]; @@ -1931,6 +1923,7 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu, } for_each_sp(pages, sp, parents, i) { + kvm_unlink_unsync_page(vcpu->kvm, sp); flush |= kvm_sync_page(vcpu, sp, &invalid_list); mmu_pages_clear_parents(&parents); } @@ -2009,7 +2002,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, if (sp->unsync) { /* - * The page is good, but is stale. __kvm_sync_page does + * The page is good, but is stale. kvm_sync_page does * get the latest guest state, but (unlike mmu_unsync_children) * it doesn't write-protect the page or mark it synchronized! * This way the validity of the mapping is ensured, but the @@ -2020,7 +2013,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, * If the sync fails, the page is zapped. If so, break * in order to rebuild it. */ - if (!__kvm_sync_page(vcpu, sp, &invalid_list)) + if (!kvm_sync_page(vcpu, sp, &invalid_list)) break; WARN_ON(!list_empty(&invalid_list));