[PATCH] kdb: add rdmsr and wrmsr commands for i386

[Mitch Bradley]

Bernardo Innocenti wrote:
> Mitch Bradley wrote:
>   
>> Bernardo Innocenti wrote:
>>     
>>> The syntax is:
>>>    rdmsr <addr>
>>>    wrmsr <addr> <l> <h>
>>>       
>> In the hardware documentation that I have seen, MSR values are 
>> conventionally shown as 64-bit numbers.  The <l> <h> ordering will make 
>> it necessary to do a mental flip.  The 32-bit pieces of MSR do not have 
>> individual addresses, so considerations of endianness are not directly 
>> relevant.
>>     
>
> I reveresed the order as you asked, but, honestly, I don't like it
> very much either way :-)
>   

Thanks.  We appreciate this patch.  It will help us a lot, because the 
Geode has so many MSRs that we have to look at again and again.

> Here's the patch again:
>
> From d03f36a5cbe079de855ef83625dbb26f11f3a2bf Mon Sep 17 00:00:00 2001
> From: Bernardo Innocenti <bernie at codewiz.org>
> Date: Tue, 15 May 2007 15:29:48 -0400
> Subject: [PATCH] kdb: add rdmsr and wrmsr commands for i386
>
> The syntax is:
>   rdmsr <addr>
>   wrmsr <addr> <h> <l>
>
> Signed-off-by: Bernardo Innocenti <bernie at codewiz.org>
> ---
>  arch/i386/kdb/kdbasupport.c |   48 +++++++++++++++++++++++++++++++++++++++---
>  kdb/kdbmain.c               |    3 +-
>  2 files changed, 45 insertions(+), 6 deletions(-)
>
> diff --git a/arch/i386/kdb/kdbasupport.c b/arch/i386/kdb/kdbasupport.c
> index 482b319..5109db9 100644
> --- a/arch/i386/kdb/kdbasupport.c
> +++ b/arch/i386/kdb/kdbasupport.c
> @@ -223,6 +223,47 @@ kdba_removedbreg(kdb_bp_t *bp)
>  	kdba_putdr7(dr7);
>  }
>  
> +static int
> +kdba_rdmsr(int argc, const char **argv)
> +{
> +	unsigned long addr;
> +	uint64_t val;
> +	int diag;
> +
> +	if (argc != 1) {
> +		return KDB_ARGCOUNT;
> +	}
> +
> +	if ((diag = kdbgetularg(argv[1], &addr)))
> +		return diag;
> +
> +	kdb_printf("msr(0x%lx) = ", addr);
> +	rdmsrl(addr, val);
> +	kdb_printf("0x%llx\n", val);
> +
> +	return 0;
> +}
> +
> +static int
> +kdba_wrmsr(int argc, const char **argv)
> +{
> +	unsigned long addr;
> +	unsigned long l, h;
> +	int diag;
> +
> +	if (argc != 3)
> +		return KDB_ARGCOUNT;
> +
> +	if ((diag = kdbgetularg(argv[1], &addr))
> +			|| (diag = kdbgetularg(argv[2], &h))
> +			|| (diag = kdbgetularg(argv[3], &l)))
> +		return diag;
> +
> +	wrmsr(addr, l, h);
> +
> +	return 0;
> +}
> +
>  
>  /*
>   * kdba_getregcontents
> @@ -474,12 +515,11 @@ kdba_setregcontents(const char *regname,
>   *	argument is NULL (struct pt_regs).   The alternate register
>   *	set types supported by this function:
>   *
> - *	d 		Debug registers
> + *	d		Debug registers
>   *	c		Control registers
>   *	u		User registers at most recent entry to kernel
>   *			for the process currently selected with "pid" command.
>   * Following not yet implemented:
> - *	m		Model Specific Registers (extra defines register #)
>   *	r		Memory Type Range Registers (extra defines register)
>   */
>  
> @@ -546,8 +586,6 @@ kdba_dumpregs(struct pt_regs *regs,
>  			   cr[0], cr[1], cr[2], cr[3], cr[4]);
>  		return 0;
>  	}
> -	case 'm':
> -		break;
>  	case 'r':
>  		break;
>  	default:
> @@ -899,6 +937,8 @@ kdba_init(void)
>  {
>  	kdb_register("pt_regs", kdba_pt_regs, "address", "Format struct pt_regs", 0);
>  	kdb_register("stackdepth", kdba_stackdepth, "[percentage]", "Print processes using >= stack percentage", 0);
> +	kdb_register("rdmsr", kdba_rdmsr, "<maddr>", "Display Model Specific Register", 0);
> +	kdb_register("wrmsr", kdba_wrmsr, "<maddr> <h> <l>", "Modify Model Specific Register", 0);
>  
>  	return;
>  }
> diff --git a/kdb/kdbmain.c b/kdb/kdbmain.c
> index 0b2cb91..88bf14f 100644
> --- a/kdb/kdbmain.c
> +++ b/kdb/kdbmain.c
> @@ -2596,8 +2596,7 @@ kdb_rd(int argc, const char **argv)
>   *	none.
>   * Remarks:
>   *	Currently doesn't allow modification of control or
> - *	debug registers, nor does it allow modification
> - *	of model-specific registers (MSR).
> + *	debug registers.
>   */
>  
>  static int
>