[PATCH v4 1/5] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks

From: Andy Lutomirski
Date: Sat Mar 12 2016 - 13:09:59 EST


These hooks match the _safe variants, so name them accordingly.
This will make room for unsafe PV hooks.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/include/asm/paravirt.h | 33 +++++++++++++++++----------------
arch/x86/include/asm/paravirt_types.h | 8 ++++----
arch/x86/kernel/paravirt.c | 4 ++--
arch/x86/xen/enlighten.c | 4 ++--
4 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index f6192502149e..2e49228ed9a3 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -129,34 +129,35 @@ static inline void wbinvd(void)

#define get_kernel_rpl() (pv_info.kernel_rpl)

-static inline u64 paravirt_read_msr(unsigned msr, int *err)
+static inline u64 paravirt_read_msr_safe(unsigned msr, int *err)
{
- return PVOP_CALL2(u64, pv_cpu_ops.read_msr, msr, err);
+ return PVOP_CALL2(u64, pv_cpu_ops.read_msr_safe, msr, err);
}

-static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned high)
+static inline int paravirt_write_msr_safe(unsigned msr,
+ unsigned low, unsigned high)
{
- return PVOP_CALL3(int, pv_cpu_ops.write_msr, msr, low, high);
+ 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(msr, &_err); \
+ u64 _l = paravirt_read_msr_safe(msr, &_err); \
val1 = (u32)_l; \
val2 = _l >> 32; \
} while (0)

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

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

static inline void wrmsrl(unsigned msr, u64 val)
@@ -164,23 +165,23 @@ static inline void wrmsrl(unsigned msr, u64 val)
wrmsr(msr, (u32)val, (u32)(val>>32));
}

-#define wrmsr_safe(msr, a, b) paravirt_write_msr(msr, a, b)
+#define wrmsr_safe(msr, a, b) paravirt_write_msr_safe(msr, a, b)

/* rdmsr with exception handling */
-#define rdmsr_safe(msr, a, b) \
-({ \
- int _err; \
- u64 _l = paravirt_read_msr(msr, &_err); \
- (*a) = (u32)_l; \
- (*b) = _l >> 32; \
- _err; \
+#define rdmsr_safe(msr, a, b) \
+({ \
+ int _err; \
+ u64 _l = paravirt_read_msr_safe(msr, &_err); \
+ (*a) = (u32)_l; \
+ (*b) = _l >> 32; \
+ _err; \
})

static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
{
int err;

- *p = paravirt_read_msr(msr, &err);
+ *p = paravirt_read_msr_safe(msr, &err);
return err;
}

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 77db5616a473..5a06cccd36f0 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -155,10 +155,10 @@ struct pv_cpu_ops {
void (*cpuid)(unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx);

- /* MSR, PMC and TSR operations.
- err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */
- u64 (*read_msr)(unsigned int msr, int *err);
- int (*write_msr)(unsigned int msr, unsigned low, unsigned high);
+ /* MSR operations.
+ err = 0/-EIO. wrmsr returns 0/-EIO. */
+ u64 (*read_msr_safe)(unsigned int msr, int *err);
+ int (*write_msr_safe)(unsigned int msr, unsigned low, unsigned high);

u64 (*read_pmc)(int counter);

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index f08ac28b8136..8aad95478ae5 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -339,8 +339,8 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
.write_cr8 = native_write_cr8,
#endif
.wbinvd = native_wbinvd,
- .read_msr = native_read_msr_safe,
- .write_msr = native_write_msr_safe,
+ .read_msr_safe = native_read_msr_safe,
+ .write_msr_safe = native_write_msr_safe,
.read_pmc = native_read_pmc,
.load_tr_desc = native_load_tr_desc,
.set_ldt = native_set_ldt,
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index d09e4c9d7cc5..ff2df20d0067 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1222,8 +1222,8 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {

.wbinvd = native_wbinvd,

- .read_msr = xen_read_msr_safe,
- .write_msr = xen_write_msr_safe,
+ .read_msr_safe = xen_read_msr_safe,
+ .write_msr_safe = xen_write_msr_safe,

.read_pmc = xen_read_pmc,

--
2.5.0