[RFC,13/35] KVM: SVM: Create trace events for VMGEXIT processing

Commit Message

Tom Lendacky Sept. 14, 2020, 8:15 p.m. UTC

From: Tom Lendacky <[e-mail]>

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 and valid bitmap fields will represent the input and output values
for the entry and exit events, respectively.

Signed-off-by: Tom Lendacky <[e-mail]>
---
 arch/x86/kvm/svm/sev.c |  6 +++++
 arch/x86/kvm/trace.h   | 55 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/x86.c     |  2 ++
 3 files changed, 63 insertions(+)

Patch

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index e085d8b83a32..f0fd89788de7 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -14,9 +14,11 @@ 
 #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 "trace.h"
 
 static int sev_flush_asids(void);
 static DECLARE_RWSEM(sev_deactivate_lock);
@@ -1185,6 +1187,8 @@  static void pre_sev_es_run(struct vcpu_svm *svm)
 	if (!svm->ghcb)
 		return;
 
+	trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->ghcb);
+
 	kvm_vcpu_unmap(&svm->vcpu, &svm->ghcb_map, true);
 	svm->ghcb = NULL;
 }
@@ -1246,6 +1250,8 @@  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);
+
 	control->exit_code = lower_32_bits(ghcb_get_sw_exit_code(ghcb));
 	control->exit_code_hi = upper_32_bits(ghcb_get_sw_exit_code(ghcb));
 	control->exit_info_1 = ghcb_get_sw_exit_info_1(ghcb);
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index b66432b015d2..06e5c15d0508 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1592,6 +1592,61 @@  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)
+		__field(u8 *, bitmap)
+	),
+
+	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;
+		__entry->bitmap      = ghcb->save.valid_bitmap;
+	),
+
+	TP_printk("vcpu %u, exit_reason %llx, exit_info1 %llx, exit_info2 %llx, valid_bitmap",
+		  __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 9970c0b7854f..ef85340e05ea 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10790,3 +10790,5 @@  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);