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 v4 05/11] KVM: MMU: do not mark accessed bit on pte write path
Date: Thu, 22 Sep 2011 16:55:36 +0800 [thread overview]
Message-ID: <4E7AF808.8080602@cn.fujitsu.com> (raw)
In-Reply-To: <4E7AF758.7060900@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 27a25df..58ea3a7 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -356,7 +356,6 @@ 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 4e53d6b..6a35024 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2206,11 +2206,6 @@ 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;
@@ -2361,10 +2356,8 @@ 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)
@@ -3532,18 +3525,6 @@ 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);
-}
-
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
const u8 *new, int bytes,
bool guest_initiated)
@@ -3614,7 +3595,6 @@ 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:[~2011-09-22 8:53 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-22 8:52 [PATCH v4 00/11] KVM: x86: optimize for writing guest page Xiao Guangrong
2011-09-22 8:53 ` [PATCH v4 01/11] KVM: MMU: avoid pte_list_desc running out in kvm_mmu_pte_write Xiao Guangrong
2011-09-22 8:53 ` [PATCH v4 02/11] KVM: x86: tag the instructions which are used to write page table Xiao Guangrong
2011-09-22 8:55 ` [PATCH v4 04/11] KVM: x86: cleanup port-in/port-out emulated Xiao Guangrong
2011-09-22 8:55 ` Xiao Guangrong [this message]
2011-09-22 8:56 ` [PATCH v4 06/11] KVM: MMU: cleanup FNAME(invlpg) Xiao Guangrong
2011-09-22 8:56 ` [PATCH v4 07/11] KVM: MMU: fast prefetch spte on invlpg path Xiao Guangrong
2011-09-22 8:56 ` [PATCH v4 08/11] KVM: MMU: remove unnecessary kvm_mmu_free_some_pages Xiao Guangrong
2011-09-22 8:57 ` [PATCH v4 09/11] KVM: MMU: split kvm_mmu_pte_write function Xiao Guangrong
2011-09-22 8:57 ` [PATCH v4 10/11] KVM: MMU: fix detecting misaligned accessed Xiao Guangrong
2011-09-22 8:58 ` [PATCH v4 11/11] KVM: MMU: improve write flooding detected Xiao Guangrong
2011-09-22 9:02 ` [PATCH v4 03/11] KVM: x86: retry non-page-table writing instructions Xiao Guangrong
2011-09-23 11:51 ` [PATCH v4 00/11] KVM: x86: optimize for writing guest page Marcelo Tosatti
2011-09-30 3:49 ` Xiao Guangrong
2011-10-05 13:25 ` Avi Kivity
2011-10-06 17:50 ` Marcelo Tosatti
2011-10-06 17:53 ` Marcelo Tosatti
2011-10-08 4:06 ` Xiao Guangrong
2011-10-09 12:24 ` Avi Kivity
2011-10-09 13:37 ` Avi Kivity
2011-10-11 8:36 ` Xiao Guangrong
2011-11-04 9:16 ` Xiao Guangrong
2011-11-06 15:35 ` Avi Kivity
2011-11-10 13:28 ` Xiao Guangrong
2011-11-10 14:05 ` Avi Kivity
2011-11-11 3:42 ` Xiao Guangrong
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