KVM: x86: Inject PMI for KVM guest

Inject a PMI for KVM guest when Intel PT working
in Host-Guest mode and Guest ToPA entry memory buffer
was completely filled.
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/events/intel/core.c

@@ -2307,7 +2307,11 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
 	 */
 	if (__test_and_clear_bit(55, (unsigned long *)&status)) {
 		handled++;
-		intel_pt_interrupt();
+		if (unlikely(perf_guest_cbs && perf_guest_cbs->is_in_guest() &&
+			perf_guest_cbs->handle_intel_pt_intr))
+			perf_guest_cbs->handle_intel_pt_intr();
+		else
+			intel_pt_interrupt();
 	}
 
 	/*

arch/x86/include/asm/msr-index.h

@@ -781,6 +781,10 @@
 #define MSR_CORE_PERF_GLOBAL_CTRL	0x0000038f
 #define MSR_CORE_PERF_GLOBAL_OVF_CTRL	0x00000390
 
+/* PERF_GLOBAL_OVF_CTL bits */
+#define MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT	55
+#define MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI		(1ULL << MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT)
+
 /* Geode defined MSRs */
 #define MSR_GEODE_BUSCONT_CONF0		0x00001900
 

arch/x86/kvm/x86.c

@@ -6839,10 +6839,20 @@ static unsigned long kvm_get_guest_ip(void)
 	return ip;
 }
 
+static void kvm_handle_intel_pt_intr(void)
+{
+	struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu);
+
+	kvm_make_request(KVM_REQ_PMI, vcpu);
+	__set_bit(MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT,
+			(unsigned long *)&vcpu->arch.pmu.global_status);
+}
+
 static struct perf_guest_info_callbacks kvm_guest_cbs = {
 	.is_in_guest		= kvm_is_in_guest,
 	.is_user_mode		= kvm_is_user_mode,
 	.get_guest_ip		= kvm_get_guest_ip,
+	.handle_intel_pt_intr	= kvm_handle_intel_pt_intr,
 };
 
 static void kvm_set_mmio_spte_mask(void)

include/linux/perf_event.h

@@ -30,6 +30,7 @@ struct perf_guest_info_callbacks {
 	int				(*is_in_guest)(void);
 	int				(*is_user_mode)(void);
 	unsigned long			(*get_guest_ip)(void);
+	void				(*handle_intel_pt_intr)(void);
 };
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT