[PATCH 33/39] KVM: MMU: Add locking around kvm_mmu_slot_remove_write_access()

From: Avi Kivity
Date: Thu Sep 25 2008 - 08:05:48 EST


From: Avi Kivity <avi@xxxxxxxxxxxx>

It was generally safe due to slots_lock being held for write, but it wasn't
very nice.

Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a24da8f..5052acd 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2097,6 +2097,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
{
struct kvm_mmu_page *sp;

+ spin_lock(&kvm->mmu_lock);
list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
int i;
u64 *pt;
@@ -2110,6 +2111,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
if (pt[i] & PT_WRITABLE_MASK)
pt[i] &= ~PT_WRITABLE_MASK;
}
+ spin_unlock(&kvm->mmu_lock);
}

void kvm_mmu_zap_all(struct kvm *kvm)
--
1.6.0.1

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