[3/4] KVM: Don't follow an atmoic operation by a non-atomic one

Commit Message

Avi Kivity Feb. 15, 2010, 12:48 p.m. UTC

None

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 38344be..0b1f0a0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3215,7 +3215,8 @@  int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 static int emulator_write_emulated_onepage(unsigned long addr,
 					   const void *val,
 					   unsigned int bytes,
-					   struct kvm_vcpu *vcpu)
+					   struct kvm_vcpu *vcpu,
+					   bool mmu_only)
 {
 	gpa_t                 gpa;
 	u32 error_code;
@@ -3231,6 +3232,10 @@  static int emulator_write_emulated_onepage(unsigned long addr,
 	if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
 		goto mmio;
 
+	if (mmu_only) {
+		kvm_mmu_pte_write(vcpu, gpa, val, bytes, 1);
+		return X86EMUL_CONTINUE;
+	}
 	if (emulator_write_phys(vcpu, gpa, val, bytes))
 		return X86EMUL_CONTINUE;
 
@@ -3251,24 +3256,35 @@  mmio:
 	return X86EMUL_CONTINUE;
 }
 
-int emulator_write_emulated(unsigned long addr,
-				   const void *val,
-				   unsigned int bytes,
-				   struct kvm_vcpu *vcpu)
+static int __emulator_write_emulated(unsigned long addr,
+				     const void *val,
+				     unsigned int bytes,
+				     struct kvm_vcpu *vcpu,
+				     bool mmu_only)
 {
 	/* Crossing a page boundary? */
 	if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
 		int rc, now;
 
 		now = -addr & ~PAGE_MASK;
-		rc = emulator_write_emulated_onepage(addr, val, now, vcpu);
+		rc = emulator_write_emulated_onepage(addr, val, now, vcpu,
+						     mmu_only);
 		if (rc != X86EMUL_CONTINUE)
 			return rc;
 		addr += now;
 		val += now;
 		bytes -= now;
 	}
-	return emulator_write_emulated_onepage(addr, val, bytes, vcpu);
+	return emulator_write_emulated_onepage(addr, val, bytes, vcpu,
+					       mmu_only);
+}
+
+int emulator_write_emulated(unsigned long addr,
+			    const void *val,
+			    unsigned int bytes,
+			    struct kvm_vcpu *vcpu)
+{
+	return __emulator_write_emulated(addr, val, bytes, vcpu, false);
 }
 EXPORT_SYMBOL_GPL(emulator_write_emulated);
 
@@ -3332,6 +3348,8 @@  static int emulator_cmpxchg_emulated(unsigned long addr,
 	if (!exchanged)
 		return X86EMUL_CMPXCHG_FAILED;
 
+	return __emulator_write_emulated(addr, new, bytes, vcpu, true);
+
 emul_write:
 	printk_once(KERN_WARNING "kvm: emulating exchange as write\n");