linux-kernel - [PATCH v4 4/5] x86: perf: Refactor misc flag assignments

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Message-ID: <20240919190750.4163977-5-coltonlewis@google.com>
Date: Thu, 19 Sep 2024 19:07:49 +0000
From: Colton Lewis <coltonlewis@...gle.com>
To: kvm@...r.kernel.org
Cc: Oliver Upton <oliver.upton@...ux.dev>, Sean Christopherson <seanjc@...gle.com>, 
	Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, 
	Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>, 
	Ian Rogers <irogers@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>, 
	Kan Liang <kan.liang@...ux.intel.com>, Will Deacon <will@...nel.org>, 
	Russell King <linux@...linux.org.uk>, Catalin Marinas <catalin.marinas@....com>, 
	Michael Ellerman <mpe@...erman.id.au>, Nicholas Piggin <npiggin@...il.com>, 
	Christophe Leroy <christophe.leroy@...roup.eu>, Naveen N Rao <naveen@...nel.org>, 
	Heiko Carstens <hca@...ux.ibm.com>, Vasily Gorbik <gor@...ux.ibm.com>, 
	Alexander Gordeev <agordeev@...ux.ibm.com>, Christian Borntraeger <borntraeger@...ux.ibm.com>, 
	Sven Schnelle <svens@...ux.ibm.com>, Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...en8.de>, 
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org, 
	"H . Peter Anvin" <hpa@...or.com>, linux-perf-users@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org, 
	Colton Lewis <coltonlewis@...gle.com>
Subject: [PATCH v4 4/5] x86: perf: 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@...gle.com>
---
 arch/x86/events/core.c            | 31 +++++++++++++++++++++++--------
 arch/x86/include/asm/perf_event.h |  2 ++
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 760ad067527c..d51e5d24802b 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2948,16 +2948,34 @@ unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
 	return regs->ip + code_segment_base(regs);
 }
 
+static unsigned long common_misc_flags(struct pt_regs *regs)
+{
+	if (regs->flags & PERF_EFLAGS_EXACT)
+		return PERF_RECORD_MISC_EXACT_IP;
+
+	return 0;
+}
+
+unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
+{
+	unsigned long guest_state = perf_guest_state();
+	unsigned long flags = common_misc_flags(regs);
+
+	if (guest_state & PERF_GUEST_USER)
+		flags |= PERF_RECORD_MISC_GUEST_USER;
+	else if (guest_state & PERF_GUEST_ACTIVE)
+		flags |= PERF_RECORD_MISC_GUEST_KERNEL;
+
+	return flags;
+}
+
 unsigned long perf_arch_misc_flags(struct pt_regs *regs)
 {
 	unsigned int guest_state = perf_guest_state();
-	int misc = 0;
+	unsigned long misc = common_misc_flags(regs);
 
 	if (guest_state) {
-		if (guest_state & PERF_GUEST_USER)
-			misc |= PERF_RECORD_MISC_GUEST_USER;
-		else
-			misc |= PERF_RECORD_MISC_GUEST_KERNEL;
+		misc |= perf_arch_guest_misc_flags(regs);
 	} else {
 		if (user_mode(regs))
 			misc |= PERF_RECORD_MISC_USER;
@@ -2965,9 +2983,6 @@ unsigned long perf_arch_misc_flags(struct pt_regs *regs)
 			misc |= PERF_RECORD_MISC_KERNEL;
 	}
 
-	if (regs->flags & PERF_EFLAGS_EXACT)
-		misc |= PERF_RECORD_MISC_EXACT_IP;
-
 	return misc;
 }
 
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index feb87bf3d2e9..d95f902acc52 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/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>
 
-- 
2.46.0.792.g87dc391469-goog