Commit 4677a3b6 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: MMU: Optimize page unshadowing 



Using kvm_mmu_lookup_page() will result in multiple scans of the hash chains;
use hlist_for_each_entry_safe() to achieve a single scan instead.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent c8a73f18

arch/x86/kvm/mmu.c

+12 −3
Original line number Diff line number Diff line
@@ -1471,13 +1471,22 @@ static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) 


static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)

{

	unsigned index;

	struct hlist_head *bucket;

	struct kvm_mmu_page *sp;

	struct hlist_node *node, *nn;



	while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {

		pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);

	index = kvm_page_table_hashfn(gfn);

	bucket = &kvm->arch.mmu_page_hash[index];

	hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) {

		if (sp->gfn == gfn && !sp->role.metaphysical

		    && !sp->role.invalid) {

			pgprintk("%s: zap %lx %x\n",

				 __func__, gfn, sp->role.word);

			kvm_mmu_zap_page(kvm, sp);

		}

	}

}



static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)

{