From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
KVM list <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH v4 8/9] KVM MMU: no need atomic operation for 'invlpg_counter'
Date: Thu, 06 May 2010 17:31:40 +0800 [thread overview]
Message-ID: <4BE28C7C.3060806@cn.fujitsu.com> (raw)
In-Reply-To: <4BE2818A.5000301@cn.fujitsu.com>
'invlpg_counter' is protected by 'kvm->mmu_lock', no need atomic
operation anymore
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/paging_tmpl.h | 7 ++++---
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 86a8550..f4e8973 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -387,7 +387,7 @@ struct kvm_arch {
unsigned int n_free_mmu_pages;
unsigned int n_requested_mmu_pages;
unsigned int n_alloc_mmu_pages;
- atomic_t invlpg_counter;
+ unsigned int invlpg_counter;
struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
/*
* Hash table of struct kvm_mmu_page.
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 93ee2d9..ceaac55 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -466,7 +466,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
struct kvm_shadow_walk_iterator iterator;
gfn_t gfn = -1;
u64 *sptep = NULL, gentry;
- int invlpg_counter, level, offset = 0, need_flush = 0;
+ unsigned int invlpg_counter;
+ int level, offset = 0, need_flush = 0;
spin_lock(&vcpu->kvm->mmu_lock);
@@ -502,7 +503,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
if (need_flush)
kvm_flush_remote_tlbs(vcpu->kvm);
- invlpg_counter = atomic_add_return(1, &vcpu->kvm->arch.invlpg_counter);
+ invlpg_counter = ++vcpu->kvm->arch.invlpg_counter;
spin_unlock(&vcpu->kvm->mmu_lock);
if (gfn == -1)
@@ -522,7 +523,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
kvm_mmu_free_page(vcpu->kvm, sp);
goto unlock_exit;
}
- if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter &&
+ if (vcpu->kvm->arch.invlpg_counter == invlpg_counter &&
sp->role.level == PT_PAGE_TABLE_LEVEL) {
++vcpu->kvm->stat.mmu_pte_updated;
FNAME(update_pte)(vcpu, sp, sptep, &gentry);
--
1.6.1.2
next prev parent reply other threads:[~2010-05-06 9:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4BE2818A.5000301@cn.fujitsu.com>
2010-05-06 9:30 ` [PATCH v4 1/9] KVM MMU: split kvm_sync_page() function Xiao Guangrong
2010-05-06 9:30 ` [PATCH v4 2/9] KVM MMU: don't write-protect if have new mapping to unsync page Xiao Guangrong
2010-05-06 9:30 ` [PATCH v4 3/9] KVM MMU: allow more page become unsync at gfn mapping time Xiao Guangrong
2010-05-06 9:30 ` [PATCH v4 4/9] KVM MMU: allow more page become unsync at getting sp time Xiao Guangrong
2010-05-06 9:31 ` [PATCH v4 5/9] KVM MMU: rename 'root_count' to 'active_count' Xiao Guangrong
2010-05-07 3:57 ` [PATCH v5 " Xiao Guangrong
2010-05-06 9:31 ` [PATCH v4 6/9] KVM MMU: support keeping sp live while it's out of protection Xiao Guangrong
2010-05-07 3:58 ` [PATCH v5 " Xiao Guangrong
2010-05-06 9:31 ` [PATCH v4 7/9] KVM MMU: separate invlpg code form kvm_mmu_pte_write() Xiao Guangrong
2010-05-06 9:31 ` Xiao Guangrong [this message]
2010-05-06 9:31 ` [PATCH v4 9/9] KVM MMU: optimize sync/update unsync-page Xiao Guangrong
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