From aaee2c94f7a1f7726e360a6cfb40173bd552bcff Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Thu, 20 Dec 2007 19:18:26 -0500 Subject: KVM: MMU: Switch to mmu spinlock Convert the synchronization of the shadow handling to a separate mmu_lock spinlock. Also guard fetch() by mmap_sem in read-mode to protect against alias and memslot changes. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 48 ++++++++++++++++++++++++++---------------------- 1 file changed, 26 insertions(+), 22 deletions(-) (limited to 'arch/x86/kvm/mmu.c') diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index c0b757be7b99..834698d24595 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -971,16 +971,12 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) { } -static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) +static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, + gfn_t gfn, struct page *page) { int level = PT32E_ROOT_LEVEL; hpa_t table_addr = vcpu->arch.mmu.root_hpa; int pt_write = 0; - struct page *page; - - down_read(¤t->mm->mmap_sem); - page = gfn_to_page(vcpu->kvm, gfn); - up_read(¤t->mm->mmap_sem); for (; ; level--) { u32 index = PT64_INDEX(v, level); @@ -1022,9 +1018,17 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) { int r; - mutex_lock(&vcpu->kvm->lock); - r = __nonpaging_map(vcpu, v, write, gfn); - mutex_unlock(&vcpu->kvm->lock); + struct page *page; + + down_read(¤t->mm->mmap_sem); + page = gfn_to_page(vcpu->kvm, gfn); + + spin_lock(&vcpu->kvm->mmu_lock); + r = __nonpaging_map(vcpu, v, write, gfn, page); + spin_unlock(&vcpu->kvm->mmu_lock); + + up_read(¤t->mm->mmap_sem); + return r; } @@ -1045,7 +1049,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) return; - mutex_lock(&vcpu->kvm->lock); + spin_lock(&vcpu->kvm->mmu_lock); #ifdef CONFIG_X86_64 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { hpa_t root = vcpu->arch.mmu.root_hpa; @@ -1053,7 +1057,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) sp = page_header(root); --sp->root_count; vcpu->arch.mmu.root_hpa = INVALID_PAGE; - mutex_unlock(&vcpu->kvm->lock); + spin_unlock(&vcpu->kvm->mmu_lock); return; } #endif @@ -1067,7 +1071,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) } vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; } - mutex_unlock(&vcpu->kvm->lock); + spin_unlock(&vcpu->kvm->mmu_lock); vcpu->arch.mmu.root_hpa = INVALID_PAGE; } @@ -1270,9 +1274,9 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) r = mmu_topup_memory_caches(vcpu); if (r) goto out; - mutex_lock(&vcpu->kvm->lock); + spin_lock(&vcpu->kvm->mmu_lock); mmu_alloc_roots(vcpu); - mutex_unlock(&vcpu->kvm->lock); + spin_unlock(&vcpu->kvm->mmu_lock); kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa); kvm_mmu_flush_tlb(vcpu); out: @@ -1408,7 +1412,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes); - mutex_lock(&vcpu->kvm->lock); + spin_lock(&vcpu->kvm->mmu_lock); ++vcpu->kvm->stat.mmu_pte_write; kvm_mmu_audit(vcpu, "pre pte write"); if (gfn == vcpu->arch.last_pt_write_gfn @@ -1477,7 +1481,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, } } kvm_mmu_audit(vcpu, "post pte write"); - mutex_unlock(&vcpu->kvm->lock); + spin_unlock(&vcpu->kvm->mmu_lock); if (vcpu->arch.update_pte.page) { kvm_release_page_clean(vcpu->arch.update_pte.page); vcpu->arch.update_pte.page = NULL; @@ -1493,15 +1497,15 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva); up_read(¤t->mm->mmap_sem); - mutex_lock(&vcpu->kvm->lock); + spin_lock(&vcpu->kvm->mmu_lock); r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); - mutex_unlock(&vcpu->kvm->lock); + spin_unlock(&vcpu->kvm->mmu_lock); return r; } void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) { - mutex_lock(&vcpu->kvm->lock); + spin_lock(&vcpu->kvm->mmu_lock); while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) { struct kvm_mmu_page *sp; @@ -1510,7 +1514,7 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) kvm_mmu_zap_page(vcpu->kvm, sp); ++vcpu->kvm->stat.mmu_recycled; } - mutex_unlock(&vcpu->kvm->lock); + spin_unlock(&vcpu->kvm->mmu_lock); } int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) @@ -1642,10 +1646,10 @@ void kvm_mmu_zap_all(struct kvm *kvm) { struct kvm_mmu_page *sp, *node; - mutex_lock(&kvm->lock); + spin_lock(&kvm->mmu_lock); list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) kvm_mmu_zap_page(kvm, sp); - mutex_unlock(&kvm->lock); + spin_unlock(&kvm->mmu_lock); kvm_flush_remote_tlbs(kvm); } -- cgit v1.2.3