Re: [PATCH] DOM0: Add Machine check support to dom0

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 01/28/2010 02:13 AM, Jiang, Yunhong wrote:
> Jeremy, this patch is to add MCE support to dom0.
>
> As currently there is no branch for MCA (the original one is really so out of date), so this patch is against xen master.
>
> Another patch will sent out as RFC to cover the smal windows between syscall entry point and stack switch.
>
> Thanks
> Yunhong Jiang
>
>   From 2fe838c3ab2d68d4019d72b2098da4c2ef97fcd8 Mon Sep 17 00:00:00 2001
> From: Jiang, Yunhong<yunhong.jiang@intel.com>
> Date: Wed, 27 Jan 2010 23:48:54 +0800
> Subject: [PATCH] Change the machine check point
>
> Enable MCE support in dom0, so that if a MCE happen and that MCE impact dom0, dom0 can receive a vMCE.
>
> Signed-off-by: Ke, Liping<liping.ke@intel.com>
> Signed-off-by: Jiang, Yunhong<yunhong.jiang@intel.com>
> ---
>   arch/x86/xen/enlighten.c |    2 +-
>   1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 7a62c2b..a8c1d34 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -531,7 +531,7 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val,
>   		return 0;
>   #ifdef CONFIG_X86_MCE
>   	} else if (addr == (unsigned long)machine_check) {
> -		return 0;
> +		addr = (unsigned long)machine_check;
>    

I just had another look at this while going through my backlog.  This is 
just a no-op.  I assume we need the test because val->ist != 0 and so 
would provoke the check, but we needn't have any body in the if(), right?

     J