[v2,1/4] KVM: fix rcu usage in init_rmode_* functions

Commit Message

Xiao Guangrong March 9, 2011, 7:41 a.m. UTC

None

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3febb76..d8475a2 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2397,11 +2397,12 @@  static bool guest_state_valid(struct kvm_vcpu *vcpu)
 
 static int init_rmode_tss(struct kvm *kvm)
 {
-	gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT;
+	gfn_t fn;
 	u16 data = 0;
-	int ret = 0;
-	int r;
+	int r, idx, ret = 0;
 
+	idx = srcu_read_lock(&kvm->srcu);
+	fn = rmode_tss_base(kvm) >> PAGE_SHIFT;
 	r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
 	if (r < 0)
 		goto out;
@@ -2425,12 +2426,13 @@  static int init_rmode_tss(struct kvm *kvm)
 
 	ret = 1;
 out:
+	srcu_read_unlock(&kvm->srcu, idx);
 	return ret;
 }
 
 static int init_rmode_identity_map(struct kvm *kvm)
 {
-	int i, r, ret;
+	int i, idx, r, ret;
 	pfn_t identity_map_pfn;
 	u32 tmp;
 
@@ -2445,6 +2447,7 @@  static int init_rmode_identity_map(struct kvm *kvm)
 		return 1;
 	ret = 0;
 	identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT;
+	idx = srcu_read_lock(&kvm->srcu);
 	r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
 	if (r < 0)
 		goto out;
@@ -2460,6 +2463,7 @@  static int init_rmode_identity_map(struct kvm *kvm)
 	kvm->arch.ept_identity_pagetable_done = true;
 	ret = 1;
 out:
+	srcu_read_unlock(&kvm->srcu, idx);
 	return ret;
 }