Subject: [PATCH] pvops/x86: remove hooks for {rd,wr}msr_safe_regs

There were paravirt_ops hooks for the full register set variant of
{rd,wr}msr_safe which are actually not used by anyone anymore.
Remove them to make the code cleaner and avoid silent breakages
when the pvops members were uninitialized.
This has been boot-tested natively and under Xen with PVOPS enabled
and disabled on one machine.

Signed-off-by: Andre Przywara <[email protected]>
---
arch/x86/include/asm/msr.h | 67 ++++++++++++++-------------------
arch/x86/include/asm/paravirt.h | 39 -------------------
arch/x86/include/asm/paravirt_types.h | 2 -
arch/x86/kernel/paravirt.c | 2 -
arch/x86/lib/msr-reg-export.c | 4 +-
arch/x86/lib/msr-reg.S | 10 ++--
arch/x86/xen/enlighten.c | 2 -
7 files changed, 35 insertions(+), 91 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 084ef95..81860cc 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -115,8 +115,8 @@ notrace static inline int native_write_msr_safe(unsigned int msr,

extern unsigned long long native_read_tsc(void);

-extern int native_rdmsr_safe_regs(u32 regs[8]);
-extern int native_wrmsr_safe_regs(u32 regs[8]);
+extern int rdmsr_safe_regs(u32 regs[8]);
+extern int wrmsr_safe_regs(u32 regs[8]);

static __always_inline unsigned long long __native_read_tsc(void)
{
@@ -187,43 +187,6 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
return err;
}

-static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
-{
- u32 gprs[8] = { 0 };
- int err;
-
- gprs[1] = msr;
- gprs[7] = 0x9c5a203a;
-
- err = native_rdmsr_safe_regs(gprs);
-
- *p = gprs[0] | ((u64)gprs[2] << 32);
-
- return err;
-}
-
-static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
-{
- u32 gprs[8] = { 0 };
-
- gprs[0] = (u32)val;
- gprs[1] = msr;
- gprs[2] = val >> 32;
- gprs[7] = 0x9c5a203a;
-
- return native_wrmsr_safe_regs(gprs);
-}
-
-static inline int rdmsr_safe_regs(u32 regs[8])
-{
- return native_rdmsr_safe_regs(regs);
-}
-
-static inline int wrmsr_safe_regs(u32 regs[8])
-{
- return native_wrmsr_safe_regs(regs);
-}
-
#define rdtscl(low) \
((low) = (u32)__native_read_tsc())

@@ -248,6 +211,32 @@ do { \

#endif /* !CONFIG_PARAVIRT */

+static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
+{
+ u32 gprs[8] = { 0 };
+ int err;
+
+ gprs[1] = msr;
+ gprs[7] = 0x9c5a203a;
+
+ err = rdmsr_safe_regs(gprs);
+
+ *p = gprs[0] | ((u64)gprs[2] << 32);
+
+ return err;
+}
+
+static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
+{
+ u32 gprs[8] = { 0 };
+
+ gprs[0] = (u32)val;
+ gprs[1] = msr;
+ gprs[2] = val >> 32;
+ gprs[7] = 0x9c5a203a;
+
+ return wrmsr_safe_regs(gprs);
+}

#define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val), \
(u32)((val) >> 32))
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 6cbbabf..ebb0cdb 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -128,21 +128,11 @@ static inline u64 paravirt_read_msr(unsigned msr, int *err)
return PVOP_CALL2(u64, pv_cpu_ops.read_msr, msr, err);
}

-static inline int paravirt_rdmsr_regs(u32 *regs)
-{
- return PVOP_CALL1(int, pv_cpu_ops.rdmsr_regs, regs);
-}
-
static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned high)
{
return PVOP_CALL3(int, pv_cpu_ops.write_msr, msr, low, high);
}

-static inline int paravirt_wrmsr_regs(u32 *regs)
-{
- return PVOP_CALL1(int, pv_cpu_ops.wrmsr_regs, regs);
-}
-
/* These should all do BUG_ON(_err), but our headers are too tangled. */
#define rdmsr(msr, val1, val2) \
do { \
@@ -176,9 +166,6 @@ do { \
_err; \
})

-#define rdmsr_safe_regs(regs) paravirt_rdmsr_regs(regs)
-#define wrmsr_safe_regs(regs) paravirt_wrmsr_regs(regs)
-
static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
{
int err;
@@ -186,32 +173,6 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
*p = paravirt_read_msr(msr, &err);
return err;
}
-static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
-{
- u32 gprs[8] = { 0 };
- int err;
-
- gprs[1] = msr;
- gprs[7] = 0x9c5a203a;
-
- err = paravirt_rdmsr_regs(gprs);
-
- *p = gprs[0] | ((u64)gprs[2] << 32);
-
- return err;
-}
-
-static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
-{
- u32 gprs[8] = { 0 };
-
- gprs[0] = (u32)val;
- gprs[1] = msr;
- gprs[2] = val >> 32;
- gprs[7] = 0x9c5a203a;
-
- return paravirt_wrmsr_regs(gprs);
-}

static inline u64 paravirt_read_tsc(void)
{
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 8e8b9a4..8613cbb 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -153,9 +153,7 @@ struct pv_cpu_ops {
/* MSR, PMC and TSR operations.
err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */
u64 (*read_msr)(unsigned int msr, int *err);
- int (*rdmsr_regs)(u32 *regs);
int (*write_msr)(unsigned int msr, unsigned low, unsigned high);
- int (*wrmsr_regs)(u32 *regs);

u64 (*read_tsc)(void);
u64 (*read_pmc)(int counter);
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 9ce8859..17fff18 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -352,9 +352,7 @@ struct pv_cpu_ops pv_cpu_ops = {
#endif
.wbinvd = native_wbinvd,
.read_msr = native_read_msr_safe,
- .rdmsr_regs = native_rdmsr_safe_regs,
.write_msr = native_write_msr_safe,
- .wrmsr_regs = native_wrmsr_safe_regs,
.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
.read_tscp = native_read_tscp,
diff --git a/arch/x86/lib/msr-reg-export.c b/arch/x86/lib/msr-reg-export.c
index a311cc5..8d6ef78 100644
--- a/arch/x86/lib/msr-reg-export.c
+++ b/arch/x86/lib/msr-reg-export.c
@@ -1,5 +1,5 @@
#include <linux/module.h>
#include <asm/msr.h>

-EXPORT_SYMBOL(native_rdmsr_safe_regs);
-EXPORT_SYMBOL(native_wrmsr_safe_regs);
+EXPORT_SYMBOL(rdmsr_safe_regs);
+EXPORT_SYMBOL(wrmsr_safe_regs);
diff --git a/arch/x86/lib/msr-reg.S b/arch/x86/lib/msr-reg.S
index 69fa106..f6d13ee 100644
--- a/arch/x86/lib/msr-reg.S
+++ b/arch/x86/lib/msr-reg.S
@@ -6,13 +6,13 @@

#ifdef CONFIG_X86_64
/*
- * int native_{rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
+ * int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
*
* reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
*
*/
.macro op_safe_regs op
-ENTRY(native_\op\()_safe_regs)
+ENTRY(\op\()_safe_regs)
CFI_STARTPROC
pushq_cfi %rbx
pushq_cfi %rbp
@@ -45,13 +45,13 @@ ENTRY(native_\op\()_safe_regs)

_ASM_EXTABLE(1b, 3b)
CFI_ENDPROC
-ENDPROC(native_\op\()_safe_regs)
+ENDPROC(\op\()_safe_regs)
.endm

#else /* X86_32 */

.macro op_safe_regs op
-ENTRY(native_\op\()_safe_regs)
+ENTRY(\op\()_safe_regs)
CFI_STARTPROC
pushl_cfi %ebx
pushl_cfi %ebp
@@ -92,7 +92,7 @@ ENTRY(native_\op\()_safe_regs)

_ASM_EXTABLE(1b, 3b)
CFI_ENDPROC
-ENDPROC(native_\op\()_safe_regs)
+ENDPROC(\op\()_safe_regs)
.endm

#endif
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index e74df95..60f1131 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1116,9 +1116,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.wbinvd = native_wbinvd,

.read_msr = native_read_msr_safe,
- .rdmsr_regs = native_rdmsr_safe_regs,
.write_msr = xen_write_msr_safe,
- .wrmsr_regs = native_wrmsr_safe_regs,

.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
--
1.7.4.4


2012-06-01 09:30:40

by Jan Beulich

[permalink] [raw]
Subject: Re: [Xen-devel] [PATCH] pvops/x86: remove hooks for {rd, wr}msr_safe_regs

>>> On 01.06.12 at 11:26, Andre Przywara <[email protected]> wrote:
> There were paravirt_ops hooks for the full register set variant of
> {rd,wr}msr_safe which are actually not used by anyone anymore.
> Remove them to make the code cleaner and avoid silent breakages
> when the pvops members were uninitialized.
> This has been boot-tested natively and under Xen with PVOPS enabled
> and disabled on one machine.
>
> Signed-off-by: Andre Przywara <[email protected]>

Acked-by: Jan Beulich <[email protected]>

> ---
> arch/x86/include/asm/msr.h | 67 ++++++++++++++-------------------
> arch/x86/include/asm/paravirt.h | 39 -------------------
> arch/x86/include/asm/paravirt_types.h | 2 -
> arch/x86/kernel/paravirt.c | 2 -
> arch/x86/lib/msr-reg-export.c | 4 +-
> arch/x86/lib/msr-reg.S | 10 ++--
> arch/x86/xen/enlighten.c | 2 -
> 7 files changed, 35 insertions(+), 91 deletions(-)
>
> diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
> index 084ef95..81860cc 100644
> --- a/arch/x86/include/asm/msr.h
> +++ b/arch/x86/include/asm/msr.h
> @@ -115,8 +115,8 @@ notrace static inline int native_write_msr_safe(unsigned
> int msr,
>
> extern unsigned long long native_read_tsc(void);
>
> -extern int native_rdmsr_safe_regs(u32 regs[8]);
> -extern int native_wrmsr_safe_regs(u32 regs[8]);
> +extern int rdmsr_safe_regs(u32 regs[8]);
> +extern int wrmsr_safe_regs(u32 regs[8]);
>
> static __always_inline unsigned long long __native_read_tsc(void)
> {
> @@ -187,43 +187,6 @@ static inline int rdmsrl_safe(unsigned msr, unsigned
> long long *p)
> return err;
> }
>
> -static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
> -{
> - u32 gprs[8] = { 0 };
> - int err;
> -
> - gprs[1] = msr;
> - gprs[7] = 0x9c5a203a;
> -
> - err = native_rdmsr_safe_regs(gprs);
> -
> - *p = gprs[0] | ((u64)gprs[2] << 32);
> -
> - return err;
> -}
> -
> -static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
> -{
> - u32 gprs[8] = { 0 };
> -
> - gprs[0] = (u32)val;
> - gprs[1] = msr;
> - gprs[2] = val >> 32;
> - gprs[7] = 0x9c5a203a;
> -
> - return native_wrmsr_safe_regs(gprs);
> -}
> -
> -static inline int rdmsr_safe_regs(u32 regs[8])
> -{
> - return native_rdmsr_safe_regs(regs);
> -}
> -
> -static inline int wrmsr_safe_regs(u32 regs[8])
> -{
> - return native_wrmsr_safe_regs(regs);
> -}
> -
> #define rdtscl(low) \
> ((low) = (u32)__native_read_tsc())
>
> @@ -248,6 +211,32 @@ do {
> \
>
> #endif /* !CONFIG_PARAVIRT */
>
> +static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
> +{
> + u32 gprs[8] = { 0 };
> + int err;
> +
> + gprs[1] = msr;
> + gprs[7] = 0x9c5a203a;
> +
> + err = rdmsr_safe_regs(gprs);
> +
> + *p = gprs[0] | ((u64)gprs[2] << 32);
> +
> + return err;
> +}
> +
> +static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
> +{
> + u32 gprs[8] = { 0 };
> +
> + gprs[0] = (u32)val;
> + gprs[1] = msr;
> + gprs[2] = val >> 32;
> + gprs[7] = 0x9c5a203a;
> +
> + return wrmsr_safe_regs(gprs);
> +}
>
> #define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val), \
> (u32)((val) >> 32))
> diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
> index 6cbbabf..ebb0cdb 100644
> --- a/arch/x86/include/asm/paravirt.h
> +++ b/arch/x86/include/asm/paravirt.h
> @@ -128,21 +128,11 @@ static inline u64 paravirt_read_msr(unsigned msr, int
> *err)
> return PVOP_CALL2(u64, pv_cpu_ops.read_msr, msr, err);
> }
>
> -static inline int paravirt_rdmsr_regs(u32 *regs)
> -{
> - return PVOP_CALL1(int, pv_cpu_ops.rdmsr_regs, regs);
> -}
> -
> static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned
> high)
> {
> return PVOP_CALL3(int, pv_cpu_ops.write_msr, msr, low, high);
> }
>
> -static inline int paravirt_wrmsr_regs(u32 *regs)
> -{
> - return PVOP_CALL1(int, pv_cpu_ops.wrmsr_regs, regs);
> -}
> -
> /* These should all do BUG_ON(_err), but our headers are too tangled. */
> #define rdmsr(msr, val1, val2) \
> do { \
> @@ -176,9 +166,6 @@ do { \
> _err; \
> })
>
> -#define rdmsr_safe_regs(regs) paravirt_rdmsr_regs(regs)
> -#define wrmsr_safe_regs(regs) paravirt_wrmsr_regs(regs)
> -
> static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
> {
> int err;
> @@ -186,32 +173,6 @@ static inline int rdmsrl_safe(unsigned msr, unsigned
> long long *p)
> *p = paravirt_read_msr(msr, &err);
> return err;
> }
> -static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
> -{
> - u32 gprs[8] = { 0 };
> - int err;
> -
> - gprs[1] = msr;
> - gprs[7] = 0x9c5a203a;
> -
> - err = paravirt_rdmsr_regs(gprs);
> -
> - *p = gprs[0] | ((u64)gprs[2] << 32);
> -
> - return err;
> -}
> -
> -static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
> -{
> - u32 gprs[8] = { 0 };
> -
> - gprs[0] = (u32)val;
> - gprs[1] = msr;
> - gprs[2] = val >> 32;
> - gprs[7] = 0x9c5a203a;
> -
> - return paravirt_wrmsr_regs(gprs);
> -}
>
> static inline u64 paravirt_read_tsc(void)
> {
> diff --git a/arch/x86/include/asm/paravirt_types.h
> b/arch/x86/include/asm/paravirt_types.h
> index 8e8b9a4..8613cbb 100644
> --- a/arch/x86/include/asm/paravirt_types.h
> +++ b/arch/x86/include/asm/paravirt_types.h
> @@ -153,9 +153,7 @@ struct pv_cpu_ops {
> /* MSR, PMC and TSR operations.
> err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */
> u64 (*read_msr)(unsigned int msr, int *err);
> - int (*rdmsr_regs)(u32 *regs);
> int (*write_msr)(unsigned int msr, unsigned low, unsigned high);
> - int (*wrmsr_regs)(u32 *regs);
>
> u64 (*read_tsc)(void);
> u64 (*read_pmc)(int counter);
> diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
> index 9ce8859..17fff18 100644
> --- a/arch/x86/kernel/paravirt.c
> +++ b/arch/x86/kernel/paravirt.c
> @@ -352,9 +352,7 @@ struct pv_cpu_ops pv_cpu_ops = {
> #endif
> .wbinvd = native_wbinvd,
> .read_msr = native_read_msr_safe,
> - .rdmsr_regs = native_rdmsr_safe_regs,
> .write_msr = native_write_msr_safe,
> - .wrmsr_regs = native_wrmsr_safe_regs,
> .read_tsc = native_read_tsc,
> .read_pmc = native_read_pmc,
> .read_tscp = native_read_tscp,
> diff --git a/arch/x86/lib/msr-reg-export.c b/arch/x86/lib/msr-reg-export.c
> index a311cc5..8d6ef78 100644
> --- a/arch/x86/lib/msr-reg-export.c
> +++ b/arch/x86/lib/msr-reg-export.c
> @@ -1,5 +1,5 @@
> #include <linux/module.h>
> #include <asm/msr.h>
>
> -EXPORT_SYMBOL(native_rdmsr_safe_regs);
> -EXPORT_SYMBOL(native_wrmsr_safe_regs);
> +EXPORT_SYMBOL(rdmsr_safe_regs);
> +EXPORT_SYMBOL(wrmsr_safe_regs);
> diff --git a/arch/x86/lib/msr-reg.S b/arch/x86/lib/msr-reg.S
> index 69fa106..f6d13ee 100644
> --- a/arch/x86/lib/msr-reg.S
> +++ b/arch/x86/lib/msr-reg.S
> @@ -6,13 +6,13 @@
>
> #ifdef CONFIG_X86_64
> /*
> - * int native_{rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
> + * int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
> *
> * reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
> *
> */
> .macro op_safe_regs op
> -ENTRY(native_\op\()_safe_regs)
> +ENTRY(\op\()_safe_regs)
> CFI_STARTPROC
> pushq_cfi %rbx
> pushq_cfi %rbp
> @@ -45,13 +45,13 @@ ENTRY(native_\op\()_safe_regs)
>
> _ASM_EXTABLE(1b, 3b)
> CFI_ENDPROC
> -ENDPROC(native_\op\()_safe_regs)
> +ENDPROC(\op\()_safe_regs)
> .endm
>
> #else /* X86_32 */
>
> .macro op_safe_regs op
> -ENTRY(native_\op\()_safe_regs)
> +ENTRY(\op\()_safe_regs)
> CFI_STARTPROC
> pushl_cfi %ebx
> pushl_cfi %ebp
> @@ -92,7 +92,7 @@ ENTRY(native_\op\()_safe_regs)
>
> _ASM_EXTABLE(1b, 3b)
> CFI_ENDPROC
> -ENDPROC(native_\op\()_safe_regs)
> +ENDPROC(\op\()_safe_regs)
> .endm
>
> #endif
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index e74df95..60f1131 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1116,9 +1116,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst
> = {
> .wbinvd = native_wbinvd,
>
> .read_msr = native_read_msr_safe,
> - .rdmsr_regs = native_rdmsr_safe_regs,
> .write_msr = xen_write_msr_safe,
> - .wrmsr_regs = native_wrmsr_safe_regs,
>
> .read_tsc = native_read_tsc,
> .read_pmc = native_read_pmc,
> --
> 1.7.4.4
>
>
>
> _______________________________________________
> Xen-devel mailing list
> [email protected]
> http://lists.xen.org/xen-devel