From 4677a3b693e035f186e2875259b9a0bb94c42fbe Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 6 Jan 2009 13:00:27 +0200 Subject: [PATCH] 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: Avi Kivity --- arch/x86/kvm/mmu.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 15850809b55b..aac0499947d8 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1471,11 +1471,20 @@ 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); - kvm_mmu_zap_page(kvm, sp); + 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); + } } }