Re: [PATCH 3/25][V3] irq_flags / halt routines

[Glauber de Oliveira Costa <gcosta@redhat.com>]

Jeremy Fitzhardinge escreveu:
> Glauber de Oliveira Costa wrote:
>> Thanks for the explanation, Andi. I understand it much better now, and
>> agree with you.
>>
>> As alternatives what we have now, we can either keep the paravirt_ops
>> as it is now for the native case, just hooking the vsmp functions in
>> place of the normal one, (there are just three ops anyway), refill the
>> paravirt_ops entirely in somewhere like vsmp.c, or similar (or maybe
>> even assigning paravirt_ops.fn = vsmp_fn on the fly, but early enough). 
> 
> One thing to note is that current code assumes the IF flag is always in
> bit 9, so if you paravirtualize this, you need to either a) make the
> vsmp version copy AC into IF to satisfy the interface, or b) add a new
> op meaning "tell me if this eflags has interrupts enabled or not".  I
> went for option a), and it seems to work OK (using bit 9 for "interrupt
> enabled" is pretty arbitrary from a Xen perspective, but not very hard
> to implement, and more localized than making all eflags tests a pvop).
> 
>     J
It is implemented like a) in the latest patch I send, following chris' 
suggestion.