Commit 378f5cd6 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Skip filling the gfn cache for guaranteed direct MMU topups 



Don't bother filling the gfn array cache when the caller is a fully
direct MMU, i.e. won't need a gfn array for shadow pages.

Reviewed-by: default avatarBen Gardon <bgardon@google.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-13-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 96880883

arch/x86/kvm/mmu/mmu.c

+10 −8
Original line number Diff line number Diff line
@@ -1102,7 +1102,7 @@ static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) 
	}

}



static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)

static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect)

{

	int r;
@@ -1115,10 +1115,12 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) 
				   PT64_ROOT_MAX_LEVEL);

	if (r)

		return r;

	if (maybe_indirect) {

		r = mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache,

					   PT64_ROOT_MAX_LEVEL);

		if (r)

			return r;

	}

	return mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,

				      PT64_ROOT_MAX_LEVEL);

}
@@ -4132,7 +4134,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 
	if (fast_page_fault(vcpu, gpa, error_code))

		return RET_PF_RETRY;



	r = mmu_topup_memory_caches(vcpu);

	r = mmu_topup_memory_caches(vcpu, false);

	if (r)

		return r;
@@ -5168,7 +5170,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) 
{

	int r;



	r = mmu_topup_memory_caches(vcpu);

	r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map);

	if (r)

		goto out;

	r = mmu_alloc_roots(vcpu);
@@ -5362,7 +5364,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 
	 * or not since pte prefetch is skiped if it does not have

	 * enough objects in the cache.

	 */

	mmu_topup_memory_caches(vcpu);

	mmu_topup_memory_caches(vcpu, true);



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

arch/x86/kvm/mmu/paging_tmpl.h

+2 −2
Original line number Diff line number Diff line
@@ -816,7 +816,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, 
		return RET_PF_EMULATE;

	}



	r = mmu_topup_memory_caches(vcpu);

	r = mmu_topup_memory_caches(vcpu, true);

	if (r)

		return r;
@@ -904,7 +904,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa) 
	 * No need to check return value here, rmap_can_add() can

	 * help us to skip pte prefetch later.

	 */

	mmu_topup_memory_caches(vcpu);

	mmu_topup_memory_caches(vcpu, true);



	if (!VALID_PAGE(root_hpa)) {

		WARN_ON(1);

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