[Xen-devel] [PATCH 1/3] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks

[Andy Lutomirski <luto@xxxxxxxxxx>]

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 10d0596433f8..9cf6e5232b0d 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -123,34 +123,35 @@ 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)
@@ -158,23 +159,23 @@ 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 ce029e4fa7c6..810e8ccaa42a 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -151,10 +151,10 @@ 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 f68e48f5f6c2..fe8cd519a796 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -349,8 +349,8 @@ __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 30d12afe52ed..8523d42d163e 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1216,8 +1216,8 @@ 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,
 
-- 
2.4.3


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