Commit 2bdb3d84 authored by Ben Gardon's avatar Ben Gardon Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Merge TDP MMU put and free root 



kvm_tdp_mmu_put_root and kvm_tdp_mmu_free_root are always called
together, so merge the functions to simplify TDP MMU root refcounting /
freeing.

Signed-off-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20210401233736.638171-5-bgardon@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4bba36d7

arch/x86/kvm/mmu/mmu.c

+2 −2
Original line number Diff line number Diff line
@@ -3120,8 +3120,8 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, 


	sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK);



	if (is_tdp_mmu_page(sp) && kvm_tdp_mmu_put_root(kvm, sp))

		kvm_tdp_mmu_free_root(kvm, sp);

	if (is_tdp_mmu_page(sp))

		kvm_tdp_mmu_put_root(kvm, sp);

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

		kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);

arch/x86/kvm/mmu/tdp_mmu.c

+25 −29
Original line number Diff line number Diff line
@@ -41,10 +41,31 @@ void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm) 
	rcu_barrier();

}



static void tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root)

static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,

			  gfn_t start, gfn_t end, bool can_yield, bool flush);



static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)

{

	if (kvm_tdp_mmu_put_root(kvm, root))

		kvm_tdp_mmu_free_root(kvm, root);

	free_page((unsigned long)sp->spt);

	kmem_cache_free(mmu_page_header_cache, sp);

}



void kvm_tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root)

{

	gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);



	lockdep_assert_held_write(&kvm->mmu_lock);



	if (--root->root_count)

		return;



	WARN_ON(!root->tdp_mmu_page);



	list_del(&root->link);



	zap_gfn_range(kvm, root, 0, max_gfn, false, false);



	tdp_mmu_free_sp(root);

}



static inline bool tdp_mmu_next_root_valid(struct kvm *kvm,
@@ -66,7 +87,7 @@ static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm, 
	struct kvm_mmu_page *next_root;



	next_root = list_next_entry(root, link);

	tdp_mmu_put_root(kvm, root);

	kvm_tdp_mmu_put_root(kvm, root);

	return next_root;

}
@@ -89,31 +110,6 @@ static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm, 
		if (kvm_mmu_page_as_id(_root) != _as_id) {		\

		} else



static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,

			  gfn_t start, gfn_t end, bool can_yield, bool flush);



static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)

{

	free_page((unsigned long)sp->spt);

	kmem_cache_free(mmu_page_header_cache, sp);

}



void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root)

{

	gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);



	lockdep_assert_held_write(&kvm->mmu_lock);



	WARN_ON(root->root_count);

	WARN_ON(!root->tdp_mmu_page);



	list_del(&root->link);



	zap_gfn_range(kvm, root, 0, max_gfn, false, false);



	tdp_mmu_free_sp(root);

}



static union kvm_mmu_page_role page_role_for_level(struct kvm_vcpu *vcpu,

						   int level)

{

arch/x86/kvm/mmu/tdp_mmu.h

+1 −9
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ 
#include <linux/kvm_host.h>



hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu);

void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root);



static inline void kvm_tdp_mmu_get_root(struct kvm *kvm,

					struct kvm_mmu_page *root)
@@ -17,14 +16,7 @@ static inline void kvm_tdp_mmu_get_root(struct kvm *kvm, 
	++root->root_count;

}



static inline bool kvm_tdp_mmu_put_root(struct kvm *kvm,

					struct kvm_mmu_page *root)

{

	lockdep_assert_held(&kvm->mmu_lock);

	--root->root_count;



	return !root->root_count;

}

void kvm_tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root);



bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id, gfn_t start,

				 gfn_t end, bool can_yield, bool flush);