[PATCH v3 1/5] x86/tdx: Add #VE tracepoint

[Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>]

From: Sean Christopherson <sean.j.christopherson@intel.com>

Add tracepoint for tracing TDX guest #VE exceptions. It will dump
RIP, exit reason, exit qual, GPA, instruction length and instruction
info for each #VE exception occurred.

Also, make trace points RCU idle safe to avoid warnings when RCU
debugging is enabled.

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---

Changes since v2:
 * Modified tdg_virtualization_exception() to dump cx,ax,dx
   register contents.

 arch/x86/include/asm/trace/tdx.h | 59 ++++++++++++++++++++++++++++++++
 arch/x86/kernel/tdx.c            |  7 ++++
 2 files changed, 66 insertions(+)
 create mode 100644 arch/x86/include/asm/trace/tdx.h

diff --git a/arch/x86/include/asm/trace/tdx.h b/arch/x86/include/asm/trace/tdx.h
new file mode 100644
index 000000000000..46bae44e12e5
--- /dev/null
+++ b/arch/x86/include/asm/trace/tdx.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(_TRACE_TDX_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TDX_H
+
+#include <linux/tracepoint.h>
+
+#include <uapi/asm/vmx.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM tdx
+
+#ifdef CONFIG_INTEL_TDX_GUEST
+
+TRACE_EVENT(tdg_virtualization_exception,
+	    TP_PROTO(u64 rip, u32 exit_reason, u64 exit_qual,
+		     u64 gpa, u32 instr_len, u32 instr_info,
+		     u64 cx, u64 ax, u64 dx),
+	    TP_ARGS(rip, exit_reason, exit_qual, gpa, instr_len,
+		    instr_info, cx, ax, dx),
+	    TP_STRUCT__entry(
+			     __field(u64, rip)
+			     __field(u64, exit_qual)
+			     __field(u64, gpa)
+			     __field(u32, exit_reason)
+			     __field(u32, instr_len)
+			     __field(u32, instr_info)
+			     __field(u64, cx)
+			     __field(u64, ax)
+			     __field(u64, dx)
+			     ),
+	    TP_fast_assign(
+			   __entry->rip = rip;
+			   __entry->exit_qual = exit_qual;
+			   __entry->gpa = gpa;
+			   __entry->exit_reason = exit_reason;
+			   __entry->instr_len = instr_len;
+			   __entry->instr_info = instr_info;
+			   __entry->cx = cx;
+			   __entry->ax = ax;
+			   __entry->dx = dx;
+			   ),
+	    TP_printk("reason %s rip 0x%016llx len %u info 0x%08x qual 0x%016llx gpa 0x%016llx cx %llx ax %llx dx %llx",
+		      __print_symbolic(__entry->exit_reason, VMX_EXIT_REASONS),
+		      __entry->rip, __entry->instr_len, __entry->instr_info,
+		      __entry->exit_qual, __entry->gpa,
+		      __entry->cx, __entry->ax, __entry->dx
+		      )
+	    );
+
+#endif // CONFIG_INTEL_TDX_GUEST
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH asm/trace/
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE tdx
+#endif /* _TRACE_TDX_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c
index 1cf2443edb90..4b41baa56958 100644
--- a/arch/x86/kernel/tdx.c
+++ b/arch/x86/kernel/tdx.c
@@ -15,6 +15,9 @@
 #include <linux/sched/signal.h> /* force_sig_fault() */
 #include <linux/swiotlb.h>
 
+#define CREATE_TRACE_POINTS
+#include <asm/trace/tdx.h>
+
 /* TDX Module call Leaf IDs */
 #define TDINFO				1
 #define TDGETVEINFO			3
@@ -407,6 +410,10 @@ int tdg_handle_virtualization_exception(struct pt_regs *regs,
 	unsigned long val;
 	int ret = 0;
 
+	trace_tdg_virtualization_exception_rcuidle(regs->ip, ve->exit_reason,
+		ve->exit_qual, ve->gpa, ve->instr_len, ve->instr_info,
+		regs->cx, regs->ax, regs->dx);
+
 	switch (ve->exit_reason) {
 	case EXIT_REASON_HLT:
 		tdg_halt();
-- 
2.25.1