Commit 3cc736b3 authored by David Matlack's avatar David Matlack Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Pass kvm pointer separately from vcpu to kvm_mmu_find_shadow_page() 



Get the kvm pointer from the caller, rather than deriving it from
vcpu->kvm, and plumb the kvm pointer all the way from
kvm_mmu_get_shadow_page(). With this change in place, the vcpu pointer
is only needed to sync indirect shadow pages. In other words,
__kvm_mmu_get_shadow_page() can now be used to get *direct* shadow pages
without a vcpu pointer. This enables eager page splitting, which needs
to allocate direct shadow pages during VM ioctls.

No functional change intended.

Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Message-Id: <20220516232138.1783324-13-dmatlack@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 336081fb

arch/x86/kvm/mmu/mmu.c

+15 −13
Original line number Diff line number Diff line
@@ -1975,7 +1975,8 @@ static void clear_sp_write_flooding_count(u64 *spte) 
	__clear_sp_write_flooding_count(sptep_to_sp(spte));

}



static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu,

static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm *kvm,

						     struct kvm_vcpu *vcpu,

						     gfn_t gfn,

						     struct hlist_head *sp_list,

						     union kvm_mmu_page_role role)
@@ -1985,7 +1986,7 @@ static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu, 
	int collisions = 0;

	LIST_HEAD(invalid_list);



	for_each_valid_sp(vcpu->kvm, sp, sp_list) {

	for_each_valid_sp(kvm, sp, sp_list) {

		if (sp->gfn != gfn) {

			collisions++;

			continue;
@@ -2002,7 +2003,7 @@ static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu, 
			 * upper-level page will be write-protected.

			 */

			if (role.level > PG_LEVEL_4K && sp->unsync)

				kvm_mmu_prepare_zap_page(vcpu->kvm, sp,

				kvm_mmu_prepare_zap_page(kvm, sp,

							 &invalid_list);

			continue;

		}
@@ -2030,7 +2031,7 @@ static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu, 


			WARN_ON(!list_empty(&invalid_list));

			if (ret > 0)

				kvm_flush_remote_tlbs(vcpu->kvm);

				kvm_flush_remote_tlbs(kvm);

		}



		__clear_sp_write_flooding_count(sp);
@@ -2039,13 +2040,13 @@ static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu, 
	}



	sp = NULL;

	++vcpu->kvm->stat.mmu_cache_miss;

	++kvm->stat.mmu_cache_miss;



out:

	kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);

	kvm_mmu_commit_zap_page(kvm, &invalid_list);



	if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions)

		vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions;

	if (collisions > kvm->stat.max_mmu_page_hash_collisions)

		kvm->stat.max_mmu_page_hash_collisions = collisions;

	return sp;

}
@@ -2089,7 +2090,8 @@ static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm, 
	return sp;

}



static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu,

static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm *kvm,

						      struct kvm_vcpu *vcpu,

						      struct shadow_page_caches *caches,

						      gfn_t gfn,

						      union kvm_mmu_page_role role)
@@ -2098,12 +2100,12 @@ static struct kvm_mmu_page *__kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 
	struct kvm_mmu_page *sp;

	bool created = false;



	sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)];

	sp_list = &kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)];



	sp = kvm_mmu_find_shadow_page(vcpu, gfn, sp_list, role);

	sp = kvm_mmu_find_shadow_page(kvm, vcpu, gfn, sp_list, role);

	if (!sp) {

		created = true;

		sp = kvm_mmu_alloc_shadow_page(vcpu->kvm, caches, gfn, sp_list, role);

		sp = kvm_mmu_alloc_shadow_page(kvm, caches, gfn, sp_list, role);

	}



	trace_kvm_mmu_get_page(sp, created);
@@ -2120,7 +2122,7 @@ static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu, 
		.gfn_array_cache = &vcpu->arch.mmu_gfn_array_cache,

	};



	return __kvm_mmu_get_shadow_page(vcpu, &caches, gfn, role);

	return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role);

}



static union kvm_mmu_page_role kvm_mmu_child_role(u64 *sptep, bool direct, unsigned int access)