Commit 51fb60d8 authored by Gui Jianfeng's avatar Gui Jianfeng Committed by Avi Kivity
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KVM: MMU: Move sync_page() first pte address calculation out of loop 



Move first pte address calculation out of loop to save some cycles.

Signed-off-by: default avatarGui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 66cbff59

arch/x86/kvm/paging_tmpl.h

+4 −2
Original line number Diff line number Diff line
@@ -572,12 +572,15 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 
{

	int i, offset, nr_present;

	bool reset_host_protection;

	gpa_t first_pte_gpa;



	offset = nr_present = 0;



	if (PTTYPE == 32)

		offset = sp->role.quadrant << PT64_LEVEL_BITS;



	first_pte_gpa = gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t);



	for (i = 0; i < PT64_ENT_PER_PAGE; i++) {

		unsigned pte_access;

		pt_element_t gpte;
@@ -587,8 +590,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) 
		if (!is_shadow_present_pte(sp->spt[i]))

			continue;



		pte_gpa = gfn_to_gpa(sp->gfn);

		pte_gpa += (i+offset) * sizeof(pt_element_t);

		pte_gpa = first_pte_gpa + i * sizeof(pt_element_t);



		if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,

					  sizeof(pt_element_t)))