Allow more page become asynchronous at getting sp time, if need create new
shadow page for gfn but it not allow unsync(level > 1), we should unsync all
gfn's unsync page
Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 47 +++++++++++++++++++++++++++++++++++++----------
1 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1c558ba..fb788fe 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1218,6 +1218,35 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
return __kvm_sync_page(vcpu, sp, true);
}
+/* @gfn should be write-protected at the call site */
+static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+ struct hlist_head *bucket;
+ struct kvm_mmu_page *s;
+ struct hlist_node *node, *n;
+ unsigned index;
+ bool flush = 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->unsync)
+ continue;
+
+ WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
+ if ((s->role.cr4_pae != !!is_pae(vcpu)) ||
+ (vcpu->arch.mmu.sync_page(vcpu, s))) {
+ kvm_mmu_zap_page(vcpu->kvm, s);
+ continue;
+ }
+ kvm_unlink_unsync_page(vcpu->kvm, s);
+ flush = true;
+ }
+
+ if (flush)
+ kvm_mmu_flush_tlb(vcpu);
+}
+
struct mmu_page_path {
struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
unsigned int idx[PT64_ROOT_LEVEL-1];
@@ -1316,8 +1345,9 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
unsigned index;
unsigned quadrant;
struct hlist_head *bucket;
- struct kvm_mmu_page *sp, *unsync_sp = NULL;
+ struct kvm_mmu_page *sp;
struct hlist_node *node, *tmp;
+ bool need_sync = false;
role = vcpu->arch.mmu.base_role;
role.level = level;
@@ -1334,17 +1364,14 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
bucket = &vcpu->kvm->arch.mmu_page_hash[index];
hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
if (sp->gfn == gfn) {
- if (sp->unsync)
- unsync_sp = sp;
+ if (!need_sync && sp->unsync)
+ need_sync = true;
if (sp->role.word != role.word)
continue;
- if (!direct && unsync_sp &&
- kvm_sync_page_transient(vcpu, unsync_sp)) {
- unsync_sp = NULL;
+ if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
break;
- }
mmu_page_add_parent_pte(vcpu, sp, parent_pte);
if (sp->unsync_children) {
@@ -1356,9 +1383,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
trace_kvm_mmu_get_page(sp, false);
return sp;
}
- if (!direct && unsync_sp)
- kvm_sync_page(vcpu, unsync_sp);
-
++vcpu->kvm->stat.mmu_cache_miss;
sp = kvm_mmu_alloc_page(vcpu, parent_pte);
if (!sp)
@@ -1369,6 +1393,9 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
if (!direct) {
if (rmap_write_protect(vcpu->kvm, gfn))
kvm_flush_remote_tlbs(vcpu->kvm);
+ if (level > PT_PAGE_TABLE_LEVEL && need_sync)
+ kvm_sync_pages(vcpu, gfn);
+
account_shadowed(vcpu->kvm, gfn);
}
if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
--
1.6.1.2
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