Commit 5c520e90 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Paolo Bonzini
Browse files

KVM: MMU: simplify mmu_need_write_protect 



Now, all non-leaf shadow page are page tracked, if gfn is not tracked
there is no non-leaf shadow page of gfn is existed, we can directly
make the shadow page of gfn to unsync

Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 56ca57f9

arch/x86/kvm/mmu.c

+7 −22
Original line number Diff line number Diff line
@@ -2444,7 +2444,7 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 
}

EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page);



static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)

static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)

{

	trace_kvm_mmu_unsync_page(sp);

	++vcpu->kvm->stat.mmu_unsync;
@@ -2453,39 +2453,24 @@ static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 
	kvm_mmu_mark_parents_unsync(sp);

}



static void kvm_unsync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)

{

	struct kvm_mmu_page *s;



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

		if (s->unsync)

			continue;

		WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);

		__kvm_unsync_page(vcpu, s);

	}

}



static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,

				   bool can_unsync)

{

	struct kvm_mmu_page *s;

	bool need_unsync = false;

	struct kvm_mmu_page *sp;



	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))

		return true;



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

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

		if (!can_unsync)

			return true;



		if (s->role.level != PT_PAGE_TABLE_LEVEL)

			return true;

		if (sp->unsync)

			continue;



		if (!s->unsync)

			need_unsync = true;

		WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL);

		kvm_unsync_page(vcpu, sp);

	}

	if (need_unsync)

		kvm_unsync_pages(vcpu, gfn);



	return false;

}

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