Re: [PATCH RFC Linux] x86/xen: allow using x2APIC under Xen without CONFIG_XEN enabled

[Jan Beulich]

>>> On 31.08.15 at 21:19, <boris.ostrovsky@xxxxxxxxxx> wrote:
> On 08/20/2015 08:04 AM, Jan Beulich wrote:
>> While commit 4cca6ea04d31c claims to not have any functional effect on
>> Xen, this isn't the case: Before that change, kernels built without
>> CONFIG_XEN_PVHVM (a dependency which meanwhile became just CONFIG_XEN)
>> were able to run in x2APIC mode just fine. Restore that behavior.
>>
>> This, however, still doesn't fix the case where CONFIG_HYPERVISOR_GUEST
>> is not enabled, but I suppose this may be regarded as intentional.
>>
>> Signed-off-by: Jan Beulich<jbeulich@xxxxxxxx>
>> ---
>> The patch is RFC solely because the way the issue gets fixed doesn't
>> look very neat, but I couldn't figure out a better way.
> 
> (+ x86 maintainers)
> 
> Can we provide something like xen_stub.c (that will have its own 
> x86_hyper ops, probably only x2apic_available and maybe detect) which is 
> built when !CONFIG_XEN?
> 
> Otherwise I see little reason to keep x2apic_available op and we should 
> revert the portion of 4cca6ea04d31c that introduced it.

Actually I've considered that last option too, but it seemed no neater
than the presented patch (yet imo better than introducing a stub file).

Jan

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/