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KVM: MMU: clenaup locking in mmu_free_roots()

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Do locking around each case separately instead of having one lock and two
unlocks. Move root_hpa assignment out of the lock.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
This commit is contained in:
Gleb Natapov 2013-05-16 11:55:51 +03:00
parent 0061d53daf
commit 35af577aac
1 changed files with 5 additions and 2 deletions
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7
arch/x86/kvm/mmu.c
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@ -2869,22 +2869,25 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
return; return;
spin_lock(&vcpu->kvm->mmu_lock);
if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL && if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL &&
(vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL || (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL ||
vcpu->arch.mmu.direct_map)) { vcpu->arch.mmu.direct_map)) {
hpa_t root = vcpu->arch.mmu.root_hpa; hpa_t root = vcpu->arch.mmu.root_hpa;
spin_lock(&vcpu->kvm->mmu_lock);
sp = page_header(root); sp = page_header(root);
--sp->root_count; --sp->root_count;
if (!sp->root_count && sp->role.invalid) { if (!sp->root_count && sp->role.invalid) {
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
} }
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
spin_unlock(&vcpu->kvm->mmu_lock); spin_unlock(&vcpu->kvm->mmu_lock);
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
return; return;
} }
spin_lock(&vcpu->kvm->mmu_lock);
for (i = 0; i < 4; ++i) { for (i = 0; i < 4; ++i) {
hpa_t root = vcpu->arch.mmu.pae_root[i]; hpa_t root = vcpu->arch.mmu.pae_root[i];