[tip:x86/apic] x86/msr: Add wrmsr_notrace()

From: tip-bot for Wanpeng Li
Date: Wed Nov 09 2016 - 16:10:52 EST


Commit-ID: b2c5ea4f759190ee9f75687a00035c1a66d0d743
Gitweb: http://git.kernel.org/tip/b2c5ea4f759190ee9f75687a00035c1a66d0d743
Author: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
AuthorDate: Mon, 7 Nov 2016 11:13:39 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 9 Nov 2016 22:03:14 +0100

x86/msr: Add wrmsr_notrace()

Required to remove the extra irq_enter()/irq_exit() in
smp_reschedule_interrupt().

Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: Mike Galbraith <efault@xxxxxx>
Link: http://lkml.kernel.org/r/1478488420-5982-2-git-send-email-wanpeng.li@xxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
arch/x86/include/asm/msr.h | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index b5fee97..9b0a232 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -115,17 +115,29 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr,
}

/* Can be uninlined because referenced by paravirt */
-notrace static inline void native_write_msr(unsigned int msr,
+static notrace inline void __native_write_msr_notrace(unsigned int msr,
unsigned low, unsigned high)
{
asm volatile("1: wrmsr\n"
"2:\n"
_ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_wrmsr_unsafe)
: : "c" (msr), "a"(low), "d" (high) : "memory");
+}
+
+/* Can be uninlined because referenced by paravirt */
+static notrace inline void native_write_msr(unsigned int msr,
+ unsigned low, unsigned high)
+{
+ __native_write_msr_notrace(msr, low, high);
if (msr_tracepoint_active(__tracepoint_write_msr))
do_trace_write_msr(msr, ((u64)high << 32 | low), 0);
}

+static inline void wrmsr_notrace(unsigned msr, unsigned low, unsigned high)
+{
+ __native_write_msr_notrace(msr, low, high);
+}
+
/* Can be uninlined because referenced by paravirt */
notrace static inline int native_write_msr_safe(unsigned int msr,
unsigned low, unsigned high)