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KVM: x86: MMU: Move mapping_level_dirty_bitmap() call in mapping_level()

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This is necessary to eliminate an extra memory slot search later.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Takuya Yoshikawa 2015-10-16 17:06:02 +09:00 committed by Paolo Bonzini
parent 5ed5c5c8fd
commit fd13690218
2 changed files with 17 additions and 18 deletions
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29
arch/x86/kvm/mmu.c
View File

@ -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); 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; 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); host_level = host_mapping_level(vcpu->kvm, large_gfn);
if (host_level == PT_PAGE_TABLE_LEVEL) 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 r;
int level; int level;
bool force_pt_level; bool force_pt_level = false;
pfn_t pfn; pfn_t pfn;
unsigned long mmu_seq; unsigned long mmu_seq;
bool map_writable, write = error_code & PFERR_WRITE_MASK; 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)) { if (likely(!force_pt_level)) {
level = mapping_level(vcpu, gfn);
/* /*
* This path builds a PAE pagetable - so we can map * This path builds a PAE pagetable - so we can map
* 2mb pages at maximum. Therefore check if the level * 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; level = PT_DIRECTORY_LEVEL;
gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
} else }
level = PT_PAGE_TABLE_LEVEL;
if (fast_page_fault(vcpu, v, level, error_code)) if (fast_page_fault(vcpu, v, level, error_code))
return 0; return 0;
@ -3495,20 +3499,15 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
if (r) if (r)
return r; return r;
if (mapping_level_dirty_bitmap(vcpu, gfn) || force_pt_level = !check_hugepage_cache_consistency(vcpu, gfn,
!check_hugepage_cache_consistency(vcpu, gfn, PT_DIRECTORY_LEVEL)) PT_DIRECTORY_LEVEL);
force_pt_level = true; level = mapping_level(vcpu, gfn, &force_pt_level);
else
force_pt_level = false;
if (likely(!force_pt_level)) { if (likely(!force_pt_level)) {
level = mapping_level(vcpu, gfn);
if (level > PT_DIRECTORY_LEVEL && if (level > PT_DIRECTORY_LEVEL &&
!check_hugepage_cache_consistency(vcpu, gfn, level)) !check_hugepage_cache_consistency(vcpu, gfn, level))
level = PT_DIRECTORY_LEVEL; level = PT_DIRECTORY_LEVEL;
gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
} else }
level = PT_PAGE_TABLE_LEVEL;
if (fast_page_fault(vcpu, gpa, level, error_code)) if (fast_page_fault(vcpu, gpa, level, error_code))
return 0; return 0;

6
arch/x86/kvm/paging_tmpl.h
View File

@ -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); &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable);
if (walker.level >= PT_DIRECTORY_LEVEL && !is_self_change_mapping) { if (walker.level >= PT_DIRECTORY_LEVEL && !is_self_change_mapping) {
force_pt_level = mapping_level_dirty_bitmap(vcpu, walker.gfn); level = mapping_level(vcpu, walker.gfn, &force_pt_level);
if (!force_pt_level) { if (likely(!force_pt_level)) {
level = min(walker.level, mapping_level(vcpu, walker.gfn)); level = min(walker.level, level);
walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1);
} }
} else } else