[RFC PATCH v2 12/33] KVM: SVM: Create trace events for VMGEXIT processing

[Tom Lendacky]

From: Tom Lendacky <thomas.lendacky@xxxxxxx>

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@xxxxxxx>
---
 arch/x86/kvm/svm/sev.c |  6 +++++
 arch/x86/kvm/trace.h   | 53 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/x86.c     |  2 ++
 3 files changed, 61 insertions(+)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 06a7b63641af..500c845f4979 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -14,10 +14,12 @@
 #include <linux/psp-sev.h>
 #include <linux/pagemap.h>
 #include <linux/swap.h>
+#include <linux/trace_events.h>
 
 #include "x86.h"
 #include "svm.h"
 #include "cpuid.h"
+#include "trace.h"
 
 static int sev_flush_asids(void);
 static DECLARE_RWSEM(sev_deactivate_lock);
@@ -1372,6 +1374,8 @@ 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);
@@ -1436,6 +1440,8 @@ 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 6b9125f49ddc..bc73ae18b90c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11174,3 +11174,5 @@ 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);
-- 
2.28.0