KVM: SVM: Create trace events for VMGEXIT processing

Add trace events for entry to and exit from VMGEXIT processing. The vCPU
id and the exit reason will be common for the trace events. The exit info
fields will represent the input and output values for the entry and exit
events, respectively.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <25357dca49a38372e8f483753fb0c1c2a70a6898.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

3 files changed, 61 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index db123562e7d5..089951cbe28e 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -15,10 +15,12 @@
 #include <linux/pagemap.h>
 #include <linux/swap.h>
 #include <linux/processor.h>
+#include <linux/trace_events.h>
 
 #include "x86.h"
 #include "svm.h"
 #include "cpuid.h"
+#include "trace.h"
 
 static u8 sev_enc_bit;
 static int sev_flush_asids(void);
@@ -1468,6 +1470,8 @@ static void pre_sev_es_run(struct vcpu_svm *svm)
 	if (!svm->ghcb)
 		return;
 
+	trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->ghcb);
+
 	sev_es_sync_to_ghcb(svm);
 
 	kvm_vcpu_unmap(&svm->vcpu, &svm->ghcb_map, true);
@@ -1617,6 +1621,8 @@ int sev_handle_vmgexit(struct vcpu_svm *svm)
 	svm->ghcb = svm->ghcb_map.hva;
 	ghcb = svm->ghcb_map.hva;
 
+	trace_kvm_vmgexit_enter(svm->vcpu.vcpu_id, ghcb);
+
 	exit_code = ghcb_get_sw_exit_code(ghcb);
 
 	ret = sev_es_validate_vmgexit(svm);
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index aef960f90f26..7da931a511c9 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1578,6 +1578,59 @@ TRACE_EVENT(kvm_hv_syndbg_get_msr,
 		  __entry->vcpu_id, __entry->vp_index, __entry->msr,
 		  __entry->data)
 );
+
+/*
+ * Tracepoint for the start of VMGEXIT processing
+ */
+TRACE_EVENT(kvm_vmgexit_enter,
+	TP_PROTO(unsigned int vcpu_id, struct ghcb *ghcb),
+	TP_ARGS(vcpu_id, ghcb),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, vcpu_id)
+		__field(u64, exit_reason)
+		__field(u64, info1)
+		__field(u64, info2)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_id     = vcpu_id;
+		__entry->exit_reason = ghcb->save.sw_exit_code;
+		__entry->info1       = ghcb->save.sw_exit_info_1;
+		__entry->info2       = ghcb->save.sw_exit_info_2;
+	),
+
+	TP_printk("vcpu %u, exit_reason %llx, exit_info1 %llx, exit_info2 %llx",
+		  __entry->vcpu_id, __entry->exit_reason,
+		  __entry->info1, __entry->info2)
+);
+
+/*
+ * Tracepoint for the end of VMGEXIT processing
+ */
+TRACE_EVENT(kvm_vmgexit_exit,
+	TP_PROTO(unsigned int vcpu_id, struct ghcb *ghcb),
+	TP_ARGS(vcpu_id, ghcb),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, vcpu_id)
+		__field(u64, exit_reason)
+		__field(u64, info1)
+		__field(u64, info2)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_id     = vcpu_id;
+		__entry->exit_reason = ghcb->save.sw_exit_code;
+		__entry->info1       = ghcb->save.sw_exit_info_1;
+		__entry->info2       = ghcb->save.sw_exit_info_2;
+	),
+
+	TP_printk("vcpu %u, exit_reason %llx, exit_info1 %llx, exit_info2 %llx",
+		  __entry->vcpu_id, __entry->exit_reason,
+		  __entry->info1, __entry->info2)
+);
+
 #endif /* _TRACE_KVM_H */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d88e334b19e7..10704bd8c38a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11314,3 +11314,5 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_incomplete_ipi);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_ga_log);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_apicv_update_request);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_enter);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_exit);