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 <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1585080..aac0499 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1471,11 +1471,20 @@
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);
+ }
}
}