[PATCH 2/3] perf/x86/intel/pt: Inject PMI for KVM guest

[Luwei Kang]

Inject a PMI for KVM guest when Intel PT working
in Host-Guest mode and Guest ToPA entry memory buffer
was completely filled.

The definition of âkvm_make_requestâ and âKVM_REQ_PMIâ
depend on "linux/kvm_host.h" header.

Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
---
 arch/x86/events/intel/pt.c       | 12 +++++++++++-
 arch/x86/include/asm/intel_pt.h  |  1 +
 arch/x86/include/asm/msr-index.h |  4 ++++
 arch/x86/kvm/x86.h               |  6 ++++++
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 9494ca6..09375bd 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <linux/kvm_host.h>
 
 #include <asm/perf_event.h>
 #include <asm/insn.h>
@@ -33,7 +34,8 @@
 #include "../perf_event.h"
 #include "pt.h"
 
-static DEFINE_PER_CPU(struct pt, pt_ctx);
+DEFINE_PER_CPU(struct pt, pt_ctx);
+EXPORT_PER_CPU_SYMBOL_GPL(pt_ctx);
 
 static struct pt_pmu pt_pmu;
 
@@ -1260,6 +1262,14 @@ void intel_pt_interrupt(void)
 	struct pt_buffer *buf;
 	struct perf_event *event = pt->handle.event;
 
+	if (pt->vcpu) {
+		/* Inject PMI to Guest */
+		kvm_make_request(KVM_REQ_PMI, pt->vcpu);
+		__set_bit(MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT,
+			(unsigned long *)&pt->vcpu->arch.pmu.global_status);
+		return;
+	}
+
 	/*
 	 * There may be a dangling PT bit in the interrupt status register
 	 * after PT has been disabled by pt_event_stop(). Make sure we don't
diff --git a/arch/x86/include/asm/intel_pt.h b/arch/x86/include/asm/intel_pt.h
index ee960fb..32da2e9 100644
--- a/arch/x86/include/asm/intel_pt.h
+++ b/arch/x86/include/asm/intel_pt.h
@@ -62,6 +62,7 @@ struct pt {
 	struct pt_filters       filters;
 	int                     handle_nmi;
 	int                     vmx_on;
+	struct kvm_vcpu         *vcpu;
 };
 
 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 8e40c24..ae01fb0 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -775,6 +775,10 @@
 #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
 
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 224cd0a..a9ee498 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -4,6 +4,7 @@
 
 #include <linux/kvm_host.h>
 #include <asm/pvclock.h>
+#include <asm/intel_pt.h>
 #include "kvm_cache_regs.h"
 
 #define KVM_DEFAULT_PLE_GAP		128
@@ -331,15 +332,20 @@ static inline bool kvm_pause_in_guest(struct kvm *kvm)
 }
 
 DECLARE_PER_CPU(struct kvm_vcpu *, current_vcpu);
+DECLARE_PER_CPU(struct pt, pt_ctx);
 
 static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu)
 {
 	__this_cpu_write(current_vcpu, vcpu);
+	if (kvm_x86_ops->pt_supported())
+		this_cpu_ptr(&pt_ctx)->vcpu = vcpu;
 }
 
 static inline void kvm_after_interrupt(struct kvm_vcpu *vcpu)
 {
 	__this_cpu_write(current_vcpu, NULL);
+	if (kvm_x86_ops->pt_supported())
+		this_cpu_ptr(&pt_ctx)->vcpu = NULL;
 }
 
 #endif
-- 
1.8.3.1