Re: [PATCH v3 7/10] KVM MMU: allow more page become unsync at gfn mapping time

Previous thread: linux-next: manual merge of the drm tree with Linus' tree by Stephen Rothwell on Tuesday, April 27, 2010 - 8:58 pm. (1 message)

Next thread: [PATCH v3 8/10] KVM MMU: allow more page become unsync at getting sp time by Xiao Guangrong on Tuesday, April 27, 2010 - 8:55 pm. (1 message)
From: Xiao Guangrong
Date: Tuesday, April 27, 2010 - 8:55 pm

In current code, shadow page can become asynchronous only if one
shadow page for a gfn, this rule is too strict, in fact, we can
let all last mapping page(i.e, it's the pte page) become unsync,
and sync them at invlpg or flush tlb time.

This patch allow more page become asynchronous at gfn mapping time 

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
 arch/x86/kvm/mmu.c |   81 +++++++++++++++++++++++----------------------------
 1 files changed, 37 insertions(+), 44 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index fb0c33c..a60cd51 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1166,26 +1166,6 @@ 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);
@@ -1751,47 +1731,60 @@ 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;
 ...
From: Marcelo Tosatti
Date: Friday, April 30, 2010 - 12:33 pm

Xiao,

This patch breaks Fedora 8 32 install. Reverted patches 5-10.

--

From: Xiao Guangrong
Date: Wednesday, May 5, 2010 - 5:16 am

Hi Marcelo,

Sorry for the delay reply since i'm on holiday.

I have found the reason of this issue, two fix patches will be sent soon,
could you please try it?

Thanks,
Xiao
--

Previous thread: linux-next: manual merge of the drm tree with Linus' tree by Stephen Rothwell on Tuesday, April 27, 2010 - 8:58 pm. (1 message)

Next thread: [PATCH v3 8/10] KVM MMU: allow more page become unsync at getting sp time by Xiao Guangrong on Tuesday, April 27, 2010 - 8:55 pm. (1 message)