Commit 8123f265 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Add a helper to consolidate root sp allocation 



Add a helper, mmu_alloc_root(), to consolidate the allocation of a root
shadow page, which has the same basic mechanics for all flavors of TDP
and shadow paging.

Note, __pa(sp->spt) doesn't need to be protected by mmu_lock, sp->spt
points at a kernel page.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428023714.31923-1-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3bae0459

arch/x86/kvm/mmu/mmu.c

+39 −49
Original line number Diff line number Diff line
@@ -3678,37 +3678,43 @@ static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) 
	return ret;

}



static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)

static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva,

			    u8 level, bool direct)

{

	struct kvm_mmu_page *sp;

	unsigned i;



	if (vcpu->arch.mmu->shadow_root_level >= PT64_ROOT_4LEVEL) {

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

		if(make_mmu_pages_available(vcpu) < 0) {



	if (make_mmu_pages_available(vcpu)) {

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

			return -ENOSPC;

		return INVALID_PAGE;

	}

		sp = kvm_mmu_get_page(vcpu, 0, 0,

				vcpu->arch.mmu->shadow_root_level, 1, ACC_ALL);

	sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL);

	++sp->root_count;



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

		vcpu->arch.mmu->root_hpa = __pa(sp->spt);

	} else if (vcpu->arch.mmu->shadow_root_level == PT32E_ROOT_LEVEL) {

	return __pa(sp->spt);

}



static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)

{

	u8 shadow_root_level = vcpu->arch.mmu->shadow_root_level;

	hpa_t root;

	unsigned i;



	if (shadow_root_level >= PT64_ROOT_4LEVEL) {

		root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true);

		if (!VALID_PAGE(root))

			return -ENOSPC;

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

	} else if (shadow_root_level == PT32E_ROOT_LEVEL) {

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

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

			MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i]));



			MMU_WARN_ON(VALID_PAGE(root));

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

			if (make_mmu_pages_available(vcpu) < 0) {

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

			root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT),

					      i << 30, PT32_ROOT_LEVEL, true);

			if (!VALID_PAGE(root))

				return -ENOSPC;

			}

			sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),

					i << 30, PT32_ROOT_LEVEL, 1, ACC_ALL);

			root = __pa(sp->spt);

			++sp->root_count;

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

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

		}

		vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root);
@@ -3723,9 +3729,9 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) 


static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)

{

	struct kvm_mmu_page *sp;

	u64 pdptr, pm_mask;

	gfn_t root_gfn, root_pgd;

	hpa_t root;

	int i;



	root_pgd = vcpu->arch.mmu->get_guest_pgd(vcpu);
@@ -3739,20 +3745,12 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 
	 * write-protect the guests page table root.

	 */

	if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) {

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

		MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->root_hpa));



		MMU_WARN_ON(VALID_PAGE(root));



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

		if (make_mmu_pages_available(vcpu) < 0) {

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

		root = mmu_alloc_root(vcpu, root_gfn, 0,

				      vcpu->arch.mmu->shadow_root_level, false);

		if (!VALID_PAGE(root))

			return -ENOSPC;

		}

		sp = kvm_mmu_get_page(vcpu, root_gfn, 0,

				vcpu->arch.mmu->shadow_root_level, 0, ACC_ALL);

		root = __pa(sp->spt);

		++sp->root_count;

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

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

		goto set_root_pgd;

	}
@@ -3767,9 +3765,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 
		pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK;



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

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



		MMU_WARN_ON(VALID_PAGE(root));

		MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i]));

		if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) {

			pdptr = vcpu->arch.mmu->get_pdptr(vcpu, i);

			if (!(pdptr & PT_PRESENT_MASK)) {
@@ -3780,17 +3776,11 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) 
			if (mmu_check_root(vcpu, root_gfn))

				return 1;

		}

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

		if (make_mmu_pages_available(vcpu) < 0) {

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

			return -ENOSPC;

		}

		sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL,

				      0, ACC_ALL);

		root = __pa(sp->spt);

		++sp->root_count;

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



		root = mmu_alloc_root(vcpu, root_gfn, i << 30,

				      PT32_ROOT_LEVEL, false);

		if (!VALID_PAGE(root))

			return -ENOSPC;

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

	}

	vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root);

CRA Git | Maintained and supported by SUSTech CRA and CCSE