KVM: x86: change msr numbers for kvmclock

Avi pointed out a while ago that those MSRs falls into the pentium
PMU range. So the idea here is to add new ones, and after a while,
deprecate the old ones.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/include/asm/kvm_para.h

@@ -20,6 +20,10 @@
 #define MSR_KVM_WALL_CLOCK  0x11
 #define MSR_KVM_SYSTEM_TIME 0x12
 
+/* Custom MSRs falls in the range 0x4b564d00-0x4b564dff */
+#define MSR_KVM_WALL_CLOCK_NEW  0x4b564d00
+#define MSR_KVM_SYSTEM_TIME_NEW 0x4b564d01
+
 #define KVM_MAX_MMU_OP_BATCH           32
 
 /* Operations for KVM_HC_MMU_OP */

arch/x86/kvm/x86.c

@@ -664,9 +664,10 @@ static inline u32 bit(int bitno)
  * kvm-specific. Those are put in the beginning of the list.
  */
 
-#define KVM_SAVE_MSRS_BEGIN	5
+#define KVM_SAVE_MSRS_BEGIN	7
 static u32 msrs_to_save[] = {
 	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
+	MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
 	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
 	HV_X64_MSR_APIC_ASSIST_PAGE,
 	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
@@ -1193,10 +1194,12 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 	case MSR_IA32_MISC_ENABLE:
 		vcpu->arch.ia32_misc_enable_msr = data;
 		break;
+	case MSR_KVM_WALL_CLOCK_NEW:
 	case MSR_KVM_WALL_CLOCK:
 		vcpu->kvm->arch.wall_clock = data;
 		kvm_write_wall_clock(vcpu->kvm, data);
 		break;
+	case MSR_KVM_SYSTEM_TIME_NEW:
 	case MSR_KVM_SYSTEM_TIME: {
 		if (vcpu->arch.time_page) {
 			kvm_release_page_dirty(vcpu->arch.time_page);
@@ -1468,9 +1471,11 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 		data = vcpu->arch.efer;
 		break;
 	case MSR_KVM_WALL_CLOCK:
+	case MSR_KVM_WALL_CLOCK_NEW:
 		data = vcpu->kvm->arch.wall_clock;
 		break;
 	case MSR_KVM_SYSTEM_TIME:
+	case MSR_KVM_SYSTEM_TIME_NEW:
 		data = vcpu->arch.time;
 		break;
 	case MSR_IA32_P5_MC_ADDR: