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| author | Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> | 2015-10-16 08:08:03 (GMT) |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-16 08:34:02 (GMT) |
| commit | 5225fdf8c8bea4418f69875804584c89a27c170e (patch) | |
| tree | ab26c260f44204563e5bd685cfb0686128b8eaf1 /arch/x86/kvm/mmu.c | |
| parent | d8aacf5df86a961923a2c9c547d341d64a9d9f5d (diff) | |
| download | linux-5225fdf8c8bea4418f69875804584c89a27c170e.tar.xz | |
KVM: x86: MMU: Eliminate an extra memory slot search in mapping_level()
Calling kvm_vcpu_gfn_to_memslot() twice in mapping_level() should be
avoided since getting a slot by binary search may not be negligible,
especially for virtual machines with many memory slots.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 09833b0..dd2a7c6 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -818,14 +818,11 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) kvm->arch.indirect_shadow_pages--; } -static int has_wrprotected_page(struct kvm_vcpu *vcpu, - gfn_t gfn, - int level) +static int __has_wrprotected_page(gfn_t gfn, int level, + struct kvm_memory_slot *slot) { - struct kvm_memory_slot *slot; struct kvm_lpage_info *linfo; - slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); if (slot) { linfo = lpage_info_slot(gfn, slot, level); return linfo->write_count; @@ -834,6 +831,14 @@ static int has_wrprotected_page(struct kvm_vcpu *vcpu, return 1; } +static int has_wrprotected_page(struct kvm_vcpu *vcpu, gfn_t gfn, int level) +{ + struct kvm_memory_slot *slot; + + slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); + return __has_wrprotected_page(gfn, level, slot); +} + static int host_mapping_level(struct kvm *kvm, gfn_t gfn) { unsigned long page_size; @@ -896,7 +901,7 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, max_level = min(kvm_x86_ops->get_lpage_level(), host_level); for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level) - if (has_wrprotected_page(vcpu, large_gfn, level)) + if (__has_wrprotected_page(large_gfn, level, slot)) break; return level - 1; |