linux-kernel - [PATCH 6/6] x86/msr: reduce number of low level MSR access helpers

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Message-ID: <20250506092015.1849-7-jgross@suse.com>
Date: Tue,  6 May 2025 11:20:15 +0200
From: Juergen Gross <jgross@...e.com>
To: linux-kernel@...r.kernel.org,
	x86@...nel.org
Cc: xin@...or.com,
	Juergen Gross <jgross@...e.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	xen-devel@...ts.xenproject.org
Subject: [PATCH 6/6] x86/msr: reduce number of low level MSR access helpers

Some MSR access helpers are redundant now, so remove the no longer
needed ones.

At the same time make the native_*_msr_safe() helpers always inline.

Signed-off-by: Juergen Gross <jgross@...e.com>
---
 arch/x86/include/asm/msr.h  | 20 ++++----------------
 arch/x86/xen/enlighten_pv.c |  4 ++--
 2 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 3a94cffb6a3e..0e2ed1604015 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -101,12 +101,7 @@ static __always_inline u64 native_rdmsrq(u32 msr)
 #define native_wrmsrq(msr, val)				\
 	__wrmsrq((msr), (val))
 
-static inline u64 native_read_msr(u32 msr)
-{
-	return __rdmsr(msr);
-}
-
-static inline int native_read_msr_safe(u32 msr, u64 *p)
+static __always_inline int native_read_msr_safe(u32 msr, u64 *p)
 {
 	int err;
 	EAX_EDX_DECLARE_ARGS(val, low, high);
@@ -122,14 +117,7 @@ static inline int native_read_msr_safe(u32 msr, u64 *p)
 	return err;
 }
 
-/* Can be uninlined because referenced by paravirt */
-static inline void notrace native_write_msr(u32 msr, u64 val)
-{
-	native_wrmsrq(msr, val);
-}
-
-/* Can be uninlined because referenced by paravirt */
-static inline int notrace native_write_msr_safe(u32 msr, u64 val)
+static __always_inline int notrace native_write_msr_safe(u32 msr, u64 val)
 {
 	int err;
 
@@ -161,7 +149,7 @@ static inline u64 native_read_pmc(int counter)
 #include <linux/errno.h>
 static __always_inline u64 read_msr(u32 msr)
 {
-	return native_read_msr(msr);
+	return native_rdmsrq(msr);
 }
 
 static __always_inline int read_msr_safe(u32 msr, u64 *p)
@@ -171,7 +159,7 @@ static __always_inline int read_msr_safe(u32 msr, u64 *p)
 
 static __always_inline void write_msr(u32 msr, u64 val)
 {
-	native_write_msr(msr, val);
+	native_wrmsrq(msr, val);
 }
 
 static __always_inline int write_msr_safe(u32 msr, u64 val)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index c279b2bef7eb..ea3d7d583254 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1097,7 +1097,7 @@ static u64 xen_do_read_msr(u32 msr, int *err)
 	if (err)
 		*err = native_read_msr_safe(msr, &val);
 	else
-		val = native_read_msr(msr);
+		val = native_rdmsrq(msr);
 
 	switch (msr) {
 	case MSR_IA32_APICBASE:
@@ -1156,7 +1156,7 @@ static void xen_do_write_msr(u32 msr, u64 val, int *err)
 		if (err)
 			*err = native_write_msr_safe(msr, val);
 		else
-			native_write_msr(msr, val);
+			native_wrmsrq(msr, val);
 	}
 }
 
-- 
2.43.0