KVM: MMU: allow more page become unsync at gfn mapping time

[platform/kernel/linux-rpi.git] / arch / x86 / kvm / mmu.c

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 25d3bb2..ba119da 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1170,26 +1170,6 @@ static int mmu_unsync_walk(struct kvm_mmu_page *sp,
        return __mmu_unsync_walk(sp, pvec);
 }
 
-static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
-{
-       unsigned index;
-       struct hlist_head *bucket;
-       struct kvm_mmu_page *sp;
-       struct hlist_node *node;
-
-       pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
-       index = kvm_page_table_hashfn(gfn);
-       bucket = &kvm->arch.mmu_page_hash[index];
-       hlist_for_each_entry(sp, node, bucket, hash_link)
-               if (sp->gfn == gfn && !sp->role.direct
-                   && !sp->role.invalid) {
-                       pgprintk("%s: found role %x\n",
-                                __func__, sp->role.word);
-                       return sp;
-               }
-       return NULL;
-}
-
 static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        WARN_ON(!sp->unsync);
@@ -1759,47 +1739,61 @@ u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
 }
 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type);
 
-static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       trace_kvm_mmu_unsync_page(sp);
+       ++vcpu->kvm->stat.mmu_unsync;
+       sp->unsync = 1;
+
+       kvm_mmu_mark_parents_unsync(sp);
+       mmu_convert_notrap(sp);
+}
+
+static void kvm_unsync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
 {
-       unsigned index;
        struct hlist_head *bucket;
        struct kvm_mmu_page *s;
        struct hlist_node *node, *n;
+       unsigned index;
 
-       index = kvm_page_table_hashfn(sp->gfn);
+       index = kvm_page_table_hashfn(gfn);
        bucket = &vcpu->kvm->arch.mmu_page_hash[index];
-       /* don't unsync if pagetable is shadowed with multiple roles */
+
        hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
-               if (s->gfn != sp->gfn || s->role.direct)
+               if (s->gfn != gfn || s->role.direct || s->unsync ||
+                     s->role.invalid)
                        continue;
-               if (s->role.word != sp->role.word)
-                       return 1;
+               WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
+               __kvm_unsync_page(vcpu, s);
        }
-       trace_kvm_mmu_unsync_page(sp);
-       ++vcpu->kvm->stat.mmu_unsync;
-       sp->unsync = 1;
-
-       kvm_mmu_mark_parents_unsync(sp);
-
-       mmu_convert_notrap(sp);
-       return 0;
 }
 
 static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
                                  bool can_unsync)
 {
-       struct kvm_mmu_page *shadow;
+       unsigned index;
+       struct hlist_head *bucket;
+       struct kvm_mmu_page *s;
+       struct hlist_node *node, *n;
+       bool need_unsync = false;
+
+       index = kvm_page_table_hashfn(gfn);
+       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
+       hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
+               if (s->gfn != gfn || s->role.direct || s->role.invalid)
+                       continue;
 
-       shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
-       if (shadow) {
-               if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
+               if (s->role.level != PT_PAGE_TABLE_LEVEL)
                        return 1;
-               if (shadow->unsync)
-                       return 0;
-               if (can_unsync && oos_shadow)
-                       return kvm_unsync_page(vcpu, shadow);
-               return 1;
+
+               if (!need_unsync && !s->unsync) {
+                       if (!can_unsync || !oos_shadow)
+                               return 1;
+                       need_unsync = true;
+               }
        }
+       if (need_unsync)
+               kvm_unsync_pages(vcpu, gfn);
        return 0;
 }