[PATCH] [5/7] Readd rdmsrl_safe

[Andi Kleen <andi@firstfloor.org>]

RDMSR for 64bit values with exception handling.

Makes it easier to deal with 64bit valued MSRs. The old 64bit code
base had that too as checking_rdmsrl(), but it got dropped somehow. 

Needed for followup patch.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 include/asm-x86/msr.h      |    3 +++
 include/asm-x86/paravirt.h |    4 ++++
 2 files changed, 7 insertions(+)

Index: linux/include/asm-x86/msr.h
===================================================================
--- linux.orig/include/asm-x86/msr.h
+++ linux/include/asm-x86/msr.h
@@ -150,6 +150,9 @@ static inline int wrmsr_safe(unsigned ms
 		__err;							\
 	})
 
+#define rdmsrl_safe(msr,p) \
+	({ int __err; *(p) = native_read_msr_safe(msr, &__err); __err; })
+
 #define rdtscl(low)						\
 	((low) = (u32)native_read_tsc())
 
Index: linux/include/asm-x86/paravirt.h
===================================================================
--- linux.orig/include/asm-x86/paravirt.h
+++ linux/include/asm-x86/paravirt.h
@@ -687,6 +687,10 @@ static inline int paravirt_write_msr(uns
 	(*b) = _l >> 32;			\
 	_err; })
 
+#define rdmsrl_safe(msr, p) ({			\
+	int _err;				\
+	*(p) = paravirt_read_msr(msr, &_err);	\
+	_err; })
 
 static inline u64 paravirt_read_tsc(void)
 {