From: Avi Kivity <avi@qumranet.com>
Date: Wed, 27 Aug 2008 13:32:24 +0000 (+0300)
Subject: KVM: MMU: Add locking around kvm_mmu_slot_remove_write_access()
X-Git-Tag: v2.6.28-rc1~269^2~61
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=2245a28fe2e6fdb1bdabc4dcde1ea3a5c37e2a9e;p=linux-2.6-omap-h63xx.git

KVM: MMU: Add locking around kvm_mmu_slot_remove_write_access()

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

Signed-off-by: Avi Kivity <avi@qumranet.com>
---

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a24da8f2ee9..5052acdc0a7 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)