From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
Avi Kivity <avi.kivity@gmail.com>, Gleb Natapov <gleb@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: [PATCH v2 05/12] KVM: MMU: introduce vcpu_adjust_access
Date: Wed, 23 Jan 2013 18:06:36 +0800 [thread overview]
Message-ID: <50FFB62C.4070808@linux.vnet.ibm.com> (raw)
In-Reply-To: <50FFB5A1.5090708@linux.vnet.ibm.com>
Introduce it to split the code of adjusting pte_access from the large
function of set_spte
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
arch/x86/kvm/mmu.c | 63 +++++++++++++++++++++++++++++++++-------------------
1 files changed, 40 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index af8bcb2..43b7e0c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2324,25 +2324,18 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
return 0;
}
-static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
- unsigned pte_access, int level,
- gfn_t gfn, pfn_t pfn, bool speculative,
- bool can_unsync, bool host_writable)
+/*
+ * Return -1 if a race condition is detected, 1 if @gfn need to be
+ * write-protected, otherwise 0 is returned.
+ */
+static int vcpu_adjust_access(struct kvm_vcpu *vcpu, u64 *sptep,
+ unsigned *pte_access, int level, gfn_t gfn,
+ bool can_unsync, bool host_writable)
{
- u64 spte;
- int ret = 0;
-
- if (set_mmio_spte(sptep, gfn, pfn, pte_access))
- return 0;
+ if (!host_writable)
+ *pte_access &= ~ACC_WRITE_MASK;
- spte = PT_PRESENT_MASK;
-
- if (host_writable)
- spte |= SPTE_HOST_WRITEABLE;
- else
- pte_access &= ~ACC_WRITE_MASK;
-
- if (pte_access & ACC_WRITE_MASK) {
+ if (*pte_access & ACC_WRITE_MASK) {
/*
* Other vcpu creates new sp in the window between
* mapping_level() and acquiring mmu-lock. We can
@@ -2351,7 +2344,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
*/
if (level > PT_PAGE_TABLE_LEVEL &&
has_wrprotected_page(vcpu->kvm, gfn, level))
- goto done;
+ return -1;
/*
* Optimization: for pte sync, if spte was writable the hash
@@ -2360,17 +2353,41 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
* Same reasoning can be applied to dirty page accounting.
*/
if (!can_unsync && is_writable_pte(*sptep))
- goto out_access_adjust;
+ return 0;
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
pgprintk("%s: found shadow page for %llx, marking ro\n",
__func__, gfn);
- ret = 1;
- pte_access &= ~ACC_WRITE_MASK;
+
+ *pte_access &= ~ACC_WRITE_MASK;
+ return 1;
}
}
-out_access_adjust:
+ return 0;
+}
+
+static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
+ unsigned pte_access, int level,
+ gfn_t gfn, pfn_t pfn, bool speculative,
+ bool can_unsync, bool host_writable)
+{
+ u64 spte;
+ int ret;
+
+ if (set_mmio_spte(sptep, gfn, pfn, pte_access))
+ return 0;
+
+ ret = vcpu_adjust_access(vcpu, sptep, &pte_access, level, gfn,
+ can_unsync, host_writable);
+ if (ret < 0)
+ return 0;
+
+ spte = PT_PRESENT_MASK;
+
+ if (host_writable)
+ spte |= SPTE_HOST_WRITEABLE;
+
if (!speculative)
spte |= shadow_accessed_mask;
@@ -2399,7 +2416,7 @@ out_access_adjust:
if (mmu_spte_update(sptep, spte))
kvm_flush_remote_tlbs(vcpu->kvm);
-done:
+
return ret;
}
--
1.7.7.6
next prev parent reply other threads:[~2013-01-23 10:06 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-23 10:04 [PATCH v2 01/12] KVM: MMU: lazily drop large spte Xiao Guangrong
2013-01-23 10:04 ` [PATCH v2 02/12] KVM: MMU: cleanup mapping-level Xiao Guangrong
2013-01-23 10:05 ` [PATCH v2 03/12] KVM: MMU: simplify mmu_set_spte Xiao Guangrong
2013-01-29 0:21 ` Marcelo Tosatti
2013-01-29 2:55 ` Xiao Guangrong
2013-01-29 21:53 ` Marcelo Tosatti
2013-01-30 3:22 ` Xiao Guangrong
2013-01-23 10:06 ` [PATCH v2 04/12] KVM: MMU: simplify set_spte Xiao Guangrong
2013-01-23 10:06 ` Xiao Guangrong [this message]
2013-01-24 10:36 ` [PATCH v2 05/12] KVM: MMU: introduce vcpu_adjust_access Gleb Natapov
2013-01-24 11:33 ` Xiao Guangrong
2013-01-23 10:07 ` [PATCH v2 06/12] KVM: MMU: introduce a static table to map guest access to spte access Xiao Guangrong
2013-01-25 0:15 ` Marcelo Tosatti
2013-01-25 2:46 ` Xiao Guangrong
2013-01-29 0:07 ` Marcelo Tosatti
2013-01-29 1:07 ` Marcelo Tosatti
2013-01-29 13:16 ` Gleb Natapov
2013-01-30 3:53 ` Xiao Guangrong
2013-01-23 10:07 ` [PATCH v2 07/12] KVM: MMU: remove pt_access in mmu_set_spte Xiao Guangrong
2013-01-23 10:08 ` [PATCH v2 08/12] KVM: MMU: cleanup __direct_map Xiao Guangrong
2013-01-23 10:09 ` [PATCH v2 09/12] KVM: MMU: introduce mmu_spte_establish Xiao Guangrong
2013-01-23 10:09 ` [PATCH v2 10/12] KVM: MMU: unify the code of walking pte list Xiao Guangrong
2013-01-27 13:28 ` Gleb Natapov
2013-01-29 3:01 ` Xiao Guangrong
2013-01-23 10:10 ` [PATCH v2 11/12] KVM: MMU: fix spte assertion Xiao Guangrong
2013-01-23 10:10 ` [PATCH v2 12/12] KVM: MMU: fast drop all spte on the pte_list Xiao Guangrong
2013-01-27 12:06 ` [PATCH v2 01/12] KVM: MMU: lazily drop large spte Gleb Natapov
2013-01-29 2:57 ` Xiao Guangrong
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