Commit 0671a8e7 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
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KVM: MMU: reduce remote tlb flush in kvm_mmu_pte_write() 



collect remote tlb flush in kvm_mmu_pte_write() path

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent f41d335a

arch/x86/kvm/mmu.c

+15 −5
Original line number Diff line number Diff line
@@ -2666,11 +2666,15 @@ static bool need_remote_flush(u64 old, u64 new) 
	return (old & ~new & PT64_PERM_MASK) != 0;

}



static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)

static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, bool zap_page,

				    bool remote_flush, bool local_flush)

{

	if (need_remote_flush(old, new))

	if (zap_page)

		return;



	if (remote_flush)

		kvm_flush_remote_tlbs(vcpu->kvm);

	else

	else if (local_flush)

		kvm_mmu_flush_tlb(vcpu);

}
@@ -2735,6 +2739,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 
	int npte;

	int r;

	int invlpg_counter;

	bool remote_flush, local_flush, zap_page;



	zap_page = remote_flush = local_flush = false;



	pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
@@ -2808,7 +2815,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 
			 */

			pgprintk("misaligned: gpa %llx bytes %d role %x\n",

				 gpa, bytes, sp->role.word);

			kvm_mmu_prepare_zap_page(vcpu->kvm, sp,

			zap_page |= !!kvm_mmu_prepare_zap_page(vcpu->kvm, sp,

						     &invalid_list);

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

			continue;
@@ -2833,16 +2840,19 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, 
			if (quadrant != sp->role.quadrant)

				continue;

		}

		local_flush = true;

		spte = &sp->spt[page_offset / sizeof(*spte)];

		while (npte--) {

			entry = *spte;

			mmu_pte_write_zap_pte(vcpu, sp, spte);

			if (gentry)

				mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);

			mmu_pte_write_flush_tlb(vcpu, entry, *spte);

			if (!remote_flush && need_remote_flush(entry, *spte))

				remote_flush = true;

			++spte;

		}

	}

	mmu_pte_write_flush_tlb(vcpu, zap_page, remote_flush, local_flush);

	kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);

	kvm_mmu_audit(vcpu, "post pte write");

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