linux-kernel - [PATCH 2/2 v2] KVM: MMU: allow more page become unsync at getting sp time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4BFA2DAD.2030601@cn.fujitsu.com>
Date:	Mon, 24 May 2010 15:41:33 +0800
From:	Xiao Guangrong <xiaoguangrong@...fujitsu.com>
To:	Avi Kivity <avi@...hat.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	KVM list <kvm@...r.kernel.org>
Subject: [PATCH 2/2 v2] KVM: MMU: allow more page become unsync at getting
 sp time

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@...fujitsu.com>
---
 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 170c8f7..e3a0ddf 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 || s->role.invalid)
+			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


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/