Xen devel - Aug 2012 - [PATCH] x86/ucode: don't crash during AP bringup on non-Intel, non-AMD CPUs

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/microcode.c
+++ b/xen/arch/x86/microcode.c
@@ -109,6 +109,9 @@ int microcode_resume_cpu(int cpu)
     struct cpu_signature nsig;
     unsigned int cpu2;
 
+    if ( !microcode_ops )
+        return 0;
+
     spin_lock(&microcode_mutex);
 
     err = microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);





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On 16/08/2012 16:22, "Jan Beulich" <JBeulich@suse.com> wrote:
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Do we support any such processors? Newer VIA processors maybe?

Anyhow,
Acked-by: Keir Fraser <keir@xen.org>
> --- a/xen/arch/x86/microcode.c
> +++ b/xen/arch/x86/microcode.c
> @@ -109,6 +109,9 @@ int microcode_resume_cpu(int cpu)
>      struct cpu_signature nsig;
>      unsigned int cpu2;
>  
> +    if ( !microcode_ops )
> +        return 0;
> +
>      spin_lock(&microcode_mutex);
>  
>      err = microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);
> 
> 
> 
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>>> On 16.08.12 at 17:28, Keir Fraser <keir@xen.org> wrote:
> On 16/08/2012 16:22, "Jan Beulich" <JBeulich@suse.com>
wrote:
> 
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> Do we support any such processors? Newer VIA processors maybe?
Exactly those - they were kind enough to lend me a system. I''m
having a patch queued for post-4.2 to enable VMX and a few
other vendor specific things on them, but of course a prereq for
testing this was that the system would boot at all under Xen.

Jan

On 16/08/2012 16:58, "Jan Beulich" <JBeulich@suse.com> wrote:
>>>> On 16.08.12 at 17:28, Keir Fraser <keir@xen.org> wrote:
>> On 16/08/2012 16:22, "Jan Beulich" <JBeulich@suse.com>
wrote:
>> 
>>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> 
>> Do we support any such processors? Newer VIA processors maybe?
> 
> Exactly those - they were kind enough to lend me a system. I''m
> having a patch queued for post-4.2 to enable VMX and a few
> other vendor specific things on them, but of course a prereq for
> testing this was that the system would boot at all under Xen.
Very cool! :-)

 -- Keir
> Jan
>