Commit 35af577a authored by Gleb Natapov's avatar Gleb Natapov
Browse files

KVM: MMU: clenaup locking in mmu_free_roots() 



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: default avatarGleb Natapov <gleb@redhat.com>
parent 0061d53d

arch/x86/kvm/mmu.c

+5 −2
Original line number Diff line number Diff line
@@ -2869,22 +2869,25 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu) 


	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))

		return;

	spin_lock(&vcpu->kvm->mmu_lock);



	if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL &&

	    (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL ||

	     vcpu->arch.mmu.direct_map)) {

		hpa_t root = vcpu->arch.mmu.root_hpa;



		spin_lock(&vcpu->kvm->mmu_lock);

		sp = page_header(root);

		--sp->root_count;

		if (!sp->root_count && sp->role.invalid) {

			kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);

			kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);

		}

		vcpu->arch.mmu.root_hpa = INVALID_PAGE;

		spin_unlock(&vcpu->kvm->mmu_lock);

		vcpu->arch.mmu.root_hpa = INVALID_PAGE;

		return;

	}



	spin_lock(&vcpu->kvm->mmu_lock);

	for (i = 0; i < 4; ++i) {

		hpa_t root = vcpu->arch.mmu.pae_root[i];