diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-06-25 00:18:59 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 13:10:24 +0200 |
| commit | af2b1c609ff52b6469d8e67696db98c93c348b0e (patch) | |
| tree | 794e4ebf8a9ed524cfbd01bc9e7f80fd110d3c2c | |
| parent | d338c73c39a6ed0d07fe3bb07c7f12fff0dd237d (diff) | |
x86: add memory barriers to wrmsr
wrmsr is a special instruction which can have arbitrary system-wide
effects. We don't want the compiler to reorder it with respect to
memory operations, so make it a memory barrier.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/asm-x86/msr.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h index 2b5f2c91db25..ca110ee73f07 100644 --- a/include/asm-x86/msr.h +++ b/include/asm-x86/msr.h @@ -66,7 +66,7 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr, static inline void native_write_msr(unsigned int msr, unsigned low, unsigned high) { - asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high)); + asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory"); } static inline int native_write_msr_safe(unsigned int msr, @@ -81,7 +81,8 @@ static inline int native_write_msr_safe(unsigned int msr, _ASM_EXTABLE(2b, 3b) : "=a" (err) : "c" (msr), "0" (low), "d" (high), - "i" (-EFAULT)); + "i" (-EFAULT) + : "memory"); return err; } |