kvm: svm: Intercept RDPRU

The RDPRU instruction gives the guest read access to the IA32_APERF
MSR and the IA32_MPERF MSR. According to volume 3 of the APM, "When
virtualization is enabled, this instruction can be intercepted by the
Hypervisor. The intercept bit is at VMCB byte offset 10h, bit 14."
Since we don't enumerate the instruction in KVM_SUPPORTED_CPUID,
intercept it and synthesize #UD.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Drew Schmitt <dasch@google.com>
Reviewed-by: Jacob Xu <jacobhxu@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/svm.h

@@ -52,6 +52,7 @@ enum {
 	INTERCEPT_MWAIT,
 	INTERCEPT_MWAIT_COND,
 	INTERCEPT_XSETBV,
+	INTERCEPT_RDPRU,
 };
 
 

arch/x86/include/uapi/asm/svm.h

@@ -75,6 +75,7 @@
 #define SVM_EXIT_MWAIT         0x08b
 #define SVM_EXIT_MWAIT_COND    0x08c
 #define SVM_EXIT_XSETBV        0x08d
+#define SVM_EXIT_RDPRU         0x08e
 #define SVM_EXIT_NPF           0x400
 #define SVM_EXIT_AVIC_INCOMPLETE_IPI		0x401
 #define SVM_EXIT_AVIC_UNACCELERATED_ACCESS	0x402

arch/x86/kvm/svm.c

@@ -1540,6 +1540,7 @@ static void init_vmcb(struct vcpu_svm *svm)
 	set_intercept(svm, INTERCEPT_SKINIT);
 	set_intercept(svm, INTERCEPT_WBINVD);
 	set_intercept(svm, INTERCEPT_XSETBV);
+	set_intercept(svm, INTERCEPT_RDPRU);
 	set_intercept(svm, INTERCEPT_RSM);
 
 	if (!kvm_mwait_in_guest(svm->vcpu.kvm)) {
@@ -3832,6 +3833,12 @@ static int xsetbv_interception(struct vcpu_svm *svm)
 	return 1;
 }
 
+static int rdpru_interception(struct vcpu_svm *svm)
+{
+	kvm_queue_exception(&svm->vcpu, UD_VECTOR);
+	return 1;
+}
+
 static int task_switch_interception(struct vcpu_svm *svm)
 {
 	u16 tss_selector;
@@ -4783,6 +4790,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
 	[SVM_EXIT_MONITOR]			= monitor_interception,
 	[SVM_EXIT_MWAIT]			= mwait_interception,
 	[SVM_EXIT_XSETBV]			= xsetbv_interception,
+	[SVM_EXIT_RDPRU]			= rdpru_interception,
 	[SVM_EXIT_NPF]				= npf_interception,
 	[SVM_EXIT_RSM]                          = rsm_interception,
 	[SVM_EXIT_AVIC_INCOMPLETE_IPI]		= avic_incomplete_ipi_interception,