Re: [Xen-devel] [PATCH] x86/cpuid: Fix booting on AMD Phenom 6-core platform

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

On 03/03/17 11:40, Andrew Cooper wrote:
> On 02/03/17 20:02, Andrew Cooper wrote:
>> c/s 5cecf60f4 "x86/cpuid: Handle leaf 0x1 in guest_cpuid()" causes Linux 4.10
>> to crash during boot.
>>
>> It turns out to be because of the reported apic_id, which was altered to be
>> more consistent across guests.  Revert back to the previous behaviour, by
>> limiting the apic_id adjustment to HVM guests only.  Whomever gets to fixes
>> topology representation is going to have a lot of fun with non-power-of-2 AMD
>> boxes.
>>
>> Reported-by: Sander Eikelenboom <linux@xxxxxxxxxxxxxx>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> 
> Sorry I forgot to CC you this.  (I keep forgetting that git doesn't
> understand Reported-by when collecting its CC list.)
> 
> Would you mind double checking this patch please?

Sure (but it will take till somewhere this evening CET though).

--
Sander

> ~Andrew
> 
>> ---
>> CC: Jan Beulich <JBeulich@xxxxxxxx>
>> ---
>>  xen/arch/x86/cpuid.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
>> index 0dd35dc..d6f6b88 100644
>> --- a/xen/arch/x86/cpuid.c
>> +++ b/xen/arch/x86/cpuid.c
>> @@ -749,7 +749,8 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
>>      case 0x1:
>>          /* TODO: Rework topology logic. */
>>          res->b &= 0x00ffffffu;
>> -        res->b |= (v->vcpu_id * 2) << 24;
>> +        if ( has_hvm_container_domain(d) )
>> +            res->b |= (v->vcpu_id * 2) << 24;
>>  
>>          /* TODO: Rework vPMU control in terms of toolstack choices. */
>>          if ( vpmu_available(v) &&
> 


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