From fd136902187838bcae3a572f41cb703553dd63b8 Mon Sep 17 00:00:00 2001 From: Takuya Yoshikawa Date: Fri, 16 Oct 2015 17:06:02 +0900 Subject: [PATCH] KVM: x86: MMU: Move mapping_level_dirty_bitmap() call in mapping_level() This is necessary to eliminate an extra memory slot search later. Signed-off-by: Takuya Yoshikawa Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 29 ++++++++++++++--------------- arch/x86/kvm/paging_tmpl.h | 6 +++--- 2 files changed, 17 insertions(+), 18 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 2262728863de..890cd694c9a2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -870,10 +870,16 @@ static bool mapping_level_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t large_gfn) return !gfn_to_memslot_dirty_bitmap(vcpu, large_gfn, true); } -static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn) +static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, + bool *force_pt_level) { int host_level, level, max_level; + if (likely(!*force_pt_level)) + *force_pt_level = mapping_level_dirty_bitmap(vcpu, large_gfn); + if (unlikely(*force_pt_level)) + return PT_PAGE_TABLE_LEVEL; + host_level = host_mapping_level(vcpu->kvm, large_gfn); if (host_level == PT_PAGE_TABLE_LEVEL) @@ -2962,14 +2968,13 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code, { int r; int level; - bool force_pt_level; + bool force_pt_level = false; pfn_t pfn; unsigned long mmu_seq; bool map_writable, write = error_code & PFERR_WRITE_MASK; - force_pt_level = mapping_level_dirty_bitmap(vcpu, gfn); + level = mapping_level(vcpu, gfn, &force_pt_level); if (likely(!force_pt_level)) { - level = mapping_level(vcpu, gfn); /* * This path builds a PAE pagetable - so we can map * 2mb pages at maximum. Therefore check if the level @@ -2979,8 +2984,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code, level = PT_DIRECTORY_LEVEL; gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); - } else - level = PT_PAGE_TABLE_LEVEL; + } if (fast_page_fault(vcpu, v, level, error_code)) return 0; @@ -3495,20 +3499,15 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code, if (r) return r; - if (mapping_level_dirty_bitmap(vcpu, gfn) || - !check_hugepage_cache_consistency(vcpu, gfn, PT_DIRECTORY_LEVEL)) - force_pt_level = true; - else - force_pt_level = false; - + force_pt_level = !check_hugepage_cache_consistency(vcpu, gfn, + PT_DIRECTORY_LEVEL); + level = mapping_level(vcpu, gfn, &force_pt_level); if (likely(!force_pt_level)) { - level = mapping_level(vcpu, gfn); if (level > PT_DIRECTORY_LEVEL && !check_hugepage_cache_consistency(vcpu, gfn, level)) level = PT_DIRECTORY_LEVEL; gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); - } else - level = PT_PAGE_TABLE_LEVEL; + } if (fast_page_fault(vcpu, gpa, level, error_code)) return 0; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 8ebc3a5560ce..bf39d0f3efa9 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -744,9 +744,9 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable); if (walker.level >= PT_DIRECTORY_LEVEL && !is_self_change_mapping) { - force_pt_level = mapping_level_dirty_bitmap(vcpu, walker.gfn); - if (!force_pt_level) { - level = min(walker.level, mapping_level(vcpu, walker.gfn)); + level = mapping_level(vcpu, walker.gfn, &force_pt_level); + if (likely(!force_pt_level)) { + level = min(walker.level, level); walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); } } else