From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: [PATCH 04/11] KVM: MMU: do not mark access bit on pte write path
Date: Tue, 26 Jul 2011 19:28:08 +0800 [thread overview]
Message-ID: <4E2EA4C8.5010103@cn.fujitsu.com> (raw)
In-Reply-To: <4E2EA3DB.7040403@cn.fujitsu.com>
In current code, the accessed bit is always set when page fault occurred,
do not need to set it on pte write path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/mmu.c | 22 +---------------------
2 files changed, 1 insertions(+), 22 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 95f55a9..ad88bfb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -355,7 +355,6 @@ struct kvm_vcpu_arch {
gfn_t last_pt_write_gfn;
int last_pt_write_count;
u64 *last_pte_updated;
- gfn_t last_pte_gfn;
struct fpu guest_fpu;
u64 xcr0;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5193de8..992a8a5 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2196,11 +2196,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
if (set_mmio_spte(sptep, gfn, pfn, pte_access))
return 0;
- /*
- * We don't set the accessed bit, since we sometimes want to see
- * whether the guest actually used the pte (in order to detect
- * demand paging).
- */
spte = PT_PRESENT_MASK;
if (!speculative)
spte |= shadow_accessed_mask;
@@ -2351,10 +2346,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
}
}
kvm_release_pfn_clean(pfn);
- if (speculative) {
+ if (speculative)
vcpu->arch.last_pte_updated = sptep;
- vcpu->arch.last_pte_gfn = gfn;
- }
}
static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
@@ -3519,18 +3512,6 @@ static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
return !!(spte && (*spte & shadow_accessed_mask));
}
-static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
-{
- u64 *spte = vcpu->arch.last_pte_updated;
-
- if (spte
- && vcpu->arch.last_pte_gfn == gfn
- && shadow_accessed_mask
- && !(*spte & shadow_accessed_mask)
- && is_shadow_present_pte(*spte))
- set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
-}
-
static int get_free_pte_list_desc_nr(struct kvm_vcpu *vcpu)
{
struct kvm_mmu_memory_cache *cache;
@@ -3604,7 +3585,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
++vcpu->kvm->stat.mmu_pte_write;
trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE);
if (guest_initiated) {
- kvm_mmu_access_page(vcpu, gfn);
if (gfn == vcpu->arch.last_pt_write_gfn
&& !last_updated_pte_accessed(vcpu)) {
++vcpu->arch.last_pt_write_count;
--
1.7.5.4
next prev parent reply other threads:[~2011-07-26 11:26 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-26 11:24 [PATCH 0/11] KVM: x86: optimize for guest page written Xiao Guangrong
2011-07-26 11:25 ` [PATCH 01/11] KVM: MMU: avoid pte_list_desc run out in kvm_mmu_pte_write Xiao Guangrong
2011-07-27 9:00 ` Avi Kivity
2011-07-27 9:37 ` Xiao Guangrong
2011-07-26 11:25 ` [PATCH 02/11] KVM: x86: cleanup pio/pout emulated Xiao Guangrong
2011-07-26 11:26 ` [PATCH 03/11] KVM: x86: fast emulate repeat string write instructions Xiao Guangrong
2011-07-26 12:27 ` Gleb Natapov
2011-07-26 13:53 ` Avi Kivity
2011-07-27 1:47 ` Xiao Guangrong
2011-07-27 4:26 ` Gleb Natapov
2011-07-27 6:32 ` Xiao Guangrong
2011-07-27 7:51 ` Gleb Natapov
2011-07-27 9:36 ` Xiao Guangrong
2011-07-27 9:04 ` Avi Kivity
2011-07-27 9:37 ` Xiao Guangrong
2011-07-26 11:28 ` Xiao Guangrong [this message]
2011-07-27 9:08 ` [PATCH 04/11] KVM: MMU: do not mark access bit on pte write path Avi Kivity
2011-07-27 10:04 ` Xiao Guangrong
2011-07-26 11:28 ` [PATCH 05/11] KVM: MMU: cleanup FNAME(invlpg) Xiao Guangrong
2011-07-26 11:29 ` [PATCH 06/11] KVM: MMU: fast prefetch spte on invlpg path Xiao Guangrong
2011-07-26 11:29 ` [PATCH 07/11] KVM: MMU: remove unnecessary kvm_mmu_free_some_pages Xiao Guangrong
2011-07-26 11:30 ` [PATCH 08/11] KVM: MMU: split kvm_mmu_pte_write function Xiao Guangrong
2011-07-26 11:31 ` [PATCH 09/11] KVM: MMU: remove the mismatch shadow page Xiao Guangrong
2011-07-27 9:11 ` Avi Kivity
2011-07-27 9:13 ` Avi Kivity
2011-07-27 10:05 ` Xiao Guangrong
2011-07-26 11:31 ` [PATCH 10/11] KVM: MMU: fix detecting misaligned accessed Xiao Guangrong
2011-07-27 9:15 ` Avi Kivity
2011-07-27 10:10 ` Xiao Guangrong
2011-07-26 11:32 ` [PATCH 11/11] KVM: MMU: improve write flooding detected Xiao Guangrong
2011-07-27 9:23 ` Avi Kivity
2011-07-27 10:20 ` Xiao Guangrong
2011-07-27 11:08 ` Avi Kivity
2011-07-28 2:43 ` Xiao Guangrong
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