[PATCH v5 8/9] x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y

From: Andy Lutomirski
Date: Sat Apr 02 2016 - 10:03:09 EST


Enabling CONFIG_PARAVIRT had an unintended side effect: rdmsr turned
into rdmsr_safe and wrmsr turned into wrmsr_safe, even on bare
metal. Undo that by using the new unsafe paravirt MSR hooks.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/include/asm/paravirt.h | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 68297d87e85c..0c99f10874e4 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -151,24 +151,21 @@ static inline int paravirt_write_msr_safe(unsigned msr,
return PVOP_CALL3(int, pv_cpu_ops.write_msr_safe, msr, low, high);
}

-/* These should all do BUG_ON(_err), but our headers are too tangled. */
#define rdmsr(msr, val1, val2) \
do { \
- int _err; \
- u64 _l = paravirt_read_msr_safe(msr, &_err); \
+ u64 _l = paravirt_read_msr(msr); \
val1 = (u32)_l; \
val2 = _l >> 32; \
} while (0)

#define wrmsr(msr, val1, val2) \
do { \
- paravirt_write_msr_safe(msr, val1, val2); \
+ paravirt_write_msr(msr, val1, val2); \
} while (0)

#define rdmsrl(msr, val) \
do { \
- int _err; \
- val = paravirt_read_msr_safe(msr, &_err); \
+ val = paravirt_read_msr(msr); \
} while (0)

static inline void wrmsrl(unsigned msr, u64 val)
--
2.5.5