[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v2 4/4] x86/apic: allow enabling x2APIC mode regardless of interrupt remapping



On 04.12.2019 14:51, Roger Pau Monné wrote:
> On Tue, Dec 03, 2019 at 04:33:09PM +0100, Jan Beulich wrote:
>> On 29.11.2019 12:28, Roger Pau Monne wrote:
>>> --- a/xen/arch/x86/apic.c
>>> +++ b/xen/arch/x86/apic.c
>>> @@ -492,7 +492,8 @@ static void __enable_x2apic(void)
>>>  
>>>  static void resume_x2apic(void)
>>>  {
>>> -    iommu_enable_x2apic();
>>> +    if ( iommu_supports_x2apic() )
>>> +        iommu_enable_x2apic();
>>
>> The hooks called by this function are __init, and at least the AMD
>> one also isn't (I think) prepared to be called more than once.
> 
> It's already called twice, there's one call to iommu_supports_x2apic
> in x2apic_bsp_setup and another one in iommu_enable_x2apic, so I think
> calling iommu_supports_x2apic multiple times is fine (or we would
> already have issues).

Ah, right - amd_iommu_prepare() bails (relatively) early when
noticing it had been called before.

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.