Commit 767d8d8d authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Paolo Bonzini
Browse files

KVM: X86/MMU: Add sp_has_gptes() 



Add sp_has_gptes() which equals to !sp->role.direct currently.

Shadow page having gptes needs to be write-protected, accounted and
responded to kvm_mmu_pte_write().

Use it in these places to replace !sp->role.direct and rename
for_each_gfn_indirect_valid_sp.

Signed-off-by: default avatarLai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220420131204.2850-2-jiangshanlai@gmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9f084f7c

arch/x86/kvm/mmu/mmu.c

+15 −7
Original line number Original line Diff line number Diff line
@@ -1853,15 +1853,23 @@ static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, 
static void kvm_mmu_commit_zap_page(struct kvm *kvm,

static void kvm_mmu_commit_zap_page(struct kvm *kvm,

				    struct list_head *invalid_list);

				    struct list_head *invalid_list);





static bool sp_has_gptes(struct kvm_mmu_page *sp)

{

	if (sp->role.direct)

		return false;



	return true;

}



#define for_each_valid_sp(_kvm, _sp, _list)				\

#define for_each_valid_sp(_kvm, _sp, _list)				\

	hlist_for_each_entry(_sp, _list, hash_link)			\

	hlist_for_each_entry(_sp, _list, hash_link)			\

		if (is_obsolete_sp((_kvm), (_sp))) {			\

		if (is_obsolete_sp((_kvm), (_sp))) {			\

		} else

		} else





#define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn)			\

#define for_each_gfn_valid_sp_with_gptes(_kvm, _sp, _gfn)		\

	for_each_valid_sp(_kvm, _sp,					\

	for_each_valid_sp(_kvm, _sp,					\

	  &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)])	\

	  &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)])	\

		if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else

		if ((_sp)->gfn != (_gfn) || !sp_has_gptes(_sp)) {} else





static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

			 struct list_head *invalid_list)

			 struct list_head *invalid_list)
@@ -2109,7 +2117,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 
	sp->gfn = gfn;

	sp->gfn = gfn;

	sp->role = role;

	sp->role = role;

	hlist_add_head(&sp->hash_link, sp_list);

	hlist_add_head(&sp->hash_link, sp_list);

	if (!direct) {

	if (sp_has_gptes(sp)) {

		account_shadowed(vcpu->kvm, sp);

		account_shadowed(vcpu->kvm, sp);

		if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn))

		if (level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn))

			kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1);

			kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1);
@@ -2318,7 +2326,7 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, 
	/* Zapping children means active_mmu_pages has become unstable. */

	/* Zapping children means active_mmu_pages has become unstable. */

	list_unstable = *nr_zapped;

	list_unstable = *nr_zapped;





	if (!sp->role.invalid && !sp->role.direct)

	if (!sp->role.invalid && sp_has_gptes(sp))

		unaccount_shadowed(kvm, sp);

		unaccount_shadowed(kvm, sp);





	if (sp->unsync)

	if (sp->unsync)
@@ -2498,7 +2506,7 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 
	pgprintk("%s: looking for gfn %llx\n", __func__, gfn);

	pgprintk("%s: looking for gfn %llx\n", __func__, gfn);

	r = 0;

	r = 0;

	write_lock(&kvm->mmu_lock);

	write_lock(&kvm->mmu_lock);

	for_each_gfn_indirect_valid_sp(kvm, sp, gfn) {

	for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) {

		pgprintk("%s: gfn %llx role %x\n", __func__, gfn,

		pgprintk("%s: gfn %llx role %x\n", __func__, gfn,

			 sp->role.word);

			 sp->role.word);

		r = 1;

		r = 1;
@@ -2560,7 +2568,7 @@ int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot, 
	 * that case, KVM must complete emulation of the guest TLB flush before

	 * that case, KVM must complete emulation of the guest TLB flush before

	 * allowing shadow pages to become unsync (writable by the guest).

	 * allowing shadow pages to become unsync (writable by the guest).

	 */

	 */

	for_each_gfn_indirect_valid_sp(kvm, sp, gfn) {

	for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) {

		if (!can_unsync)

		if (!can_unsync)

			return -EPERM;

			return -EPERM;
@@ -5298,7 +5306,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 




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

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





	for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {

	for_each_gfn_valid_sp_with_gptes(vcpu->kvm, sp, gfn) {

		if (detect_write_misaligned(sp, gpa, bytes) ||

		if (detect_write_misaligned(sp, gpa, bytes) ||

		      detect_write_flooding(sp)) {

		      detect_write_flooding(sp)) {

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

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