perf/x86: Refactor misc flag assignments

Break the assignment logic for misc flags into their own respective
functions to reduce the complexity of the nested logic.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20241113190156.2145593-5-coltonlewis@google.com

Author: coltonlewis

arch/x86/events/core.c

@@ -3011,27 +3011,52 @@ unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
 	return regs->ip + code_segment_base(regs);
 }
 
-unsigned long perf_arch_misc_flags(struct pt_regs *regs)
+static unsigned long common_misc_flags(struct pt_regs *regs)
 {
-	unsigned int guest_state = perf_guest_state();
-	int misc = 0;
+	if (regs->flags & PERF_EFLAGS_EXACT)
+		return PERF_RECORD_MISC_EXACT_IP;
 
-	if (guest_state) {
-		if (guest_state & PERF_GUEST_USER)
-			misc |= PERF_RECORD_MISC_GUEST_USER;
-		else
-			misc |= PERF_RECORD_MISC_GUEST_KERNEL;
-	} else {
-		if (user_mode(regs))
-			misc |= PERF_RECORD_MISC_USER;
-		else
-			misc |= PERF_RECORD_MISC_KERNEL;
-	}
+	return 0;
+}
 
-	if (regs->flags & PERF_EFLAGS_EXACT)
-		misc |= PERF_RECORD_MISC_EXACT_IP;
+static unsigned long guest_misc_flags(struct pt_regs *regs)
+{
+	unsigned long guest_state = perf_guest_state();
+
+	if (!(guest_state & PERF_GUEST_ACTIVE))
+		return 0;
+
+	if (guest_state & PERF_GUEST_USER)
+		return PERF_RECORD_MISC_GUEST_USER;
+	else
+		return PERF_RECORD_MISC_GUEST_KERNEL;
+
+}
+
+static unsigned long host_misc_flags(struct pt_regs *regs)
+{
+	if (user_mode(regs))
+		return PERF_RECORD_MISC_USER;
+	else
+		return PERF_RECORD_MISC_KERNEL;
+}
+
+unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
+{
+	unsigned long flags = common_misc_flags(regs);
+
+	flags |= guest_misc_flags(regs);
+
+	return flags;
+}
+
+unsigned long perf_arch_misc_flags(struct pt_regs *regs)
+{
+	unsigned long flags = common_misc_flags(regs);
+
+	flags |= host_misc_flags(regs);
 
-	return misc;
+	return flags;
 }
 
 void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)

arch/x86/include/asm/perf_event.h

@@ -538,7 +538,9 @@ struct x86_perf_regs {
 
 extern unsigned long perf_arch_instruction_pointer(struct pt_regs *regs);
 extern unsigned long perf_arch_misc_flags(struct pt_regs *regs);
+extern unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs);
 #define perf_arch_misc_flags(regs)	perf_arch_misc_flags(regs)
+#define perf_arch_guest_misc_flags(regs)	perf_arch_guest_misc_flags(regs)
 
 #include <asm/stacktrace.h>