From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: [PATCH v4 02/10] KVM: MMU: abstract spte write-protect
Date: Wed, 25 Apr 2012 12:01:35 +0800 [thread overview]
Message-ID: <4F97771F.5000605@linux.vnet.ibm.com> (raw)
In-Reply-To: <4F9776D2.7020506@linux.vnet.ibm.com>
Introduce a common function to abstract spte write-protect to
cleanup the code
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
arch/x86/kvm/mmu.c | 60 ++++++++++++++++++++++++++++++---------------------
1 files changed, 35 insertions(+), 25 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4a3cc18..e70ff38 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1041,6 +1041,34 @@ static void drop_spte(struct kvm *kvm, u64 *sptep)
rmap_remove(kvm, sptep);
}
+/* Return true if the spte is dropped. */
+static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool large,
+ bool *flush)
+{
+ u64 spte = *sptep;
+
+ if (!is_writable_pte(spte))
+ return false;
+
+ *flush |= true;
+
+ if (large) {
+ pgprintk("rmap_write_protect(large): spte %p %llx\n",
+ spte, *spte);
+ BUG_ON(!is_large_pte(spte));
+
+ drop_spte(kvm, sptep);
+ --kvm->stat.lpages;
+ return true;
+ }
+
+ rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
+ spte = spte & ~PT_WRITABLE_MASK;
+ mmu_spte_update(sptep, spte);
+
+ return false;
+}
+
static bool
__rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, int level)
{
@@ -1050,24 +1078,13 @@ __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, int level)
for (sptep = rmap_get_first(*rmapp, &iter); sptep;) {
BUG_ON(!(*sptep & PT_PRESENT_MASK));
- rmap_printk("rmap_write_protect: spte %p %llx\n", sptep, *sptep);
-
- if (!is_writable_pte(*sptep)) {
- sptep = rmap_get_next(&iter);
- continue;
- }
-
- if (level == PT_PAGE_TABLE_LEVEL) {
- mmu_spte_update(sptep, *sptep & ~PT_WRITABLE_MASK);
- sptep = rmap_get_next(&iter);
- } else {
- BUG_ON(!is_large_pte(*sptep));
- drop_spte(kvm, sptep);
- --kvm->stat.lpages;
+ if (spte_write_protect(kvm, sptep, level > PT_PAGE_TABLE_LEVEL,
+ &write_protected)) {
sptep = rmap_get_first(*rmapp, &iter);
+ continue;
}
- write_protected = true;
+ sptep = rmap_get_next(&iter);
}
return write_protected;
@@ -3902,6 +3919,7 @@ int kvm_mmu_setup(struct kvm_vcpu *vcpu)
void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
{
struct kvm_mmu_page *sp;
+ bool flush = false;
list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
int i;
@@ -3916,16 +3934,8 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
!is_last_spte(pt[i], sp->role.level))
continue;
- if (is_large_pte(pt[i])) {
- drop_spte(kvm, &pt[i]);
- --kvm->stat.lpages;
- continue;
- }
-
- /* avoid RMW */
- if (is_writable_pte(pt[i]))
- mmu_spte_update(&pt[i],
- pt[i] & ~PT_WRITABLE_MASK);
+ spte_write_protect(kvm, &pt[i],
+ is_large_pte(pt[i]), &flush);
}
}
kvm_flush_remote_tlbs(kvm);
--
1.7.7.6
next prev parent reply other threads:[~2012-04-25 4:02 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-25 4:00 [PATCH v4 00/10] KVM: MMU: fast page fault Xiao Guangrong
2012-04-25 4:01 ` [PATCH v4 01/10] KVM: MMU: return bool in __rmap_write_protect Xiao Guangrong
2012-04-25 4:01 ` Xiao Guangrong [this message]
2012-04-25 4:02 ` [PATCH v4 03/10] KVM: VMX: export PFEC.P bit on ept Xiao Guangrong
2012-04-25 4:02 ` [PATCH v4 04/10] KVM: MMU: introduce SPTE_MMU_WRITEABLE bit Xiao Guangrong
2012-04-25 4:03 ` [PATCH v4 05/10] KVM: MMU: introduce SPTE_WRITE_PROTECT bit Xiao Guangrong
2012-04-25 4:03 ` [PATCH v4 06/10] KVM: MMU: fast path of handling guest page fault Xiao Guangrong
2012-04-26 23:45 ` Marcelo Tosatti
2012-04-27 5:53 ` Xiao Guangrong
2012-04-27 14:52 ` Marcelo Tosatti
2012-04-28 6:10 ` Xiao Guangrong
2012-05-01 1:34 ` Marcelo Tosatti
2012-05-02 5:28 ` Xiao Guangrong
2012-05-02 21:07 ` Marcelo Tosatti
2012-05-03 11:26 ` Xiao Guangrong
2012-05-05 14:08 ` Marcelo Tosatti
2012-05-06 9:36 ` Avi Kivity
2012-05-07 6:52 ` Xiao Guangrong
2012-04-29 8:50 ` Takuya Yoshikawa
2012-05-01 2:31 ` Marcelo Tosatti
2012-05-02 5:39 ` Xiao Guangrong
2012-05-02 21:10 ` Marcelo Tosatti
2012-05-03 12:09 ` Xiao Guangrong
2012-05-03 12:13 ` Avi Kivity
2012-05-03 0:15 ` Takuya Yoshikawa
2012-05-03 12:23 ` Xiao Guangrong
2012-05-03 12:40 ` Takuya Yoshikawa
2012-04-25 4:04 ` [PATCH v4 07/10] KVM: MMU: lockless update spte on fast page fault path Xiao Guangrong
2012-04-25 4:04 ` [PATCH v4 08/10] KVM: MMU: trace fast page fault Xiao Guangrong
2012-04-25 4:05 ` [PATCH v4 09/10] KVM: MMU: fix kvm_mmu_pagetable_walk tracepoint Xiao Guangrong
2012-04-25 4:06 ` [PATCH v4 10/10] KVM: MMU: document mmu-lock and fast page fault Xiao Guangrong
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