From 98bba238429e200521594ed30dd1edad7faa0081 Mon Sep 17 00:00:00 2001 From: Takuya Yoshikawa Date: Thu, 26 Nov 2015 21:14:34 +0900 Subject: [PATCH] KVM: x86: MMU: Move parent_pte handling from kvm_mmu_get_page() to link_shadow_page() Every time kvm_mmu_get_page() is called with a non-NULL parent_pte argument, link_shadow_page() follows that to set the parent entry so that the new mapping will point to the returned page table. Moving parent_pte handling there allows to clean up the code because parent_pte is passed to kvm_mmu_get_page() just for mark_unsync() and mmu_page_add_parent_pte(). In addition, the patch avoids calling mark_unsync() for other parents in the sp->parent_ptes chain than the newly added parent_pte, because they have been there since before the current page fault handling started. Signed-off-by: Takuya Yoshikawa Cc: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 23 +++++++++-------------- arch/x86/kvm/paging_tmpl.h | 6 ++---- 2 files changed, 11 insertions(+), 18 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7f46e3e7ebd1..ec61b223da0a 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2119,12 +2119,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, if (sp->unsync && kvm_sync_page_transient(vcpu, sp)) break; - mmu_page_add_parent_pte(vcpu, sp, parent_pte); - if (sp->unsync_children) { + if (sp->unsync_children) kvm_make_request(KVM_REQ_MMU_SYNC, vcpu); - kvm_mmu_mark_parents_unsync(sp); - } else if (sp->unsync) - kvm_mmu_mark_parents_unsync(sp); __clear_sp_write_flooding_count(sp); trace_kvm_mmu_get_page(sp, false); @@ -2135,8 +2131,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, sp = kvm_mmu_alloc_page(vcpu, direct); - mmu_page_add_parent_pte(vcpu, sp, parent_pte); - sp->gfn = gfn; sp->role = role; hlist_add_head(&sp->hash_link, @@ -2204,7 +2198,8 @@ static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) return __shadow_walk_next(iterator, *iterator->sptep); } -static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp) +static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep, + struct kvm_mmu_page *sp) { u64 spte; @@ -2215,6 +2210,11 @@ static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp) shadow_user_mask | shadow_x_mask | shadow_accessed_mask; mmu_spte_set(sptep, spte); + + mmu_page_add_parent_pte(vcpu, sp, sptep); + + if (sp->unsync_children || sp->unsync) + mark_unsync(sptep); } static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, @@ -2273,11 +2273,6 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm, mmu_page_zap_pte(kvm, sp, sp->spt + i); } -static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte) -{ - mmu_page_remove_parent_pte(sp, parent_pte); -} - static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) { u64 *sptep; @@ -2743,7 +2738,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable, iterator.level - 1, 1, ACC_ALL, iterator.sptep); - link_shadow_page(iterator.sptep, sp); + link_shadow_page(vcpu, iterator.sptep, sp); } } return emulate; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 11650eac1c6e..0dcf9c8973b4 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -598,7 +598,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, goto out_gpte_changed; if (sp) - link_shadow_page(it.sptep, sp); + link_shadow_page(vcpu, it.sptep, sp); } for (; @@ -618,7 +618,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1, true, direct_access, it.sptep); - link_shadow_page(it.sptep, sp); + link_shadow_page(vcpu, it.sptep, sp); } clear_sp_write_flooding_count(it.sptep); @@ -629,8 +629,6 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, return emulate; out_gpte_changed: - if (sp) - kvm_mmu_put_page(sp, it.sptep); kvm_release_pfn_clean(pfn); return 0; } -- 2.30.2