Re: [Qemu-devel] [PATCH 0/6] simplify usb enabling logic and fix a Qemu crash

[Paolo Bonzini <pbonzini@redhat.com>]

On 06/01/2015 22:54, Alexander Graf wrote:
> 
> 
> On 06.01.15 21:41, Paolo Bonzini wrote:
>>
>>
>> On 06/01/2015 20:48, Paolo Bonzini wrote:
>>> I like the way you structured the series!
>>>
>>> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
>>
>> Hmm, actually doesn't this break -machine usb=no?
> 
> I think it does, but I don't think we really need to care. We can just
> assume that the 64bit mac99 always has USB and it's impossible to turn off.
> 
> For sPAPR, we only ever enable USB as convenience option when VGA is
> enabled. I think it's a pretty fair thing to do there and simply ignore
> usb=no. If you really need it, just don't use -vga.
> 
> At the end of the day, I don't think anyone will notice. I'd definitely
> prefer to keep the code simple.

Yeah, I agree.  If it's hard to fix, this patchset is okay.  But if it's
not too hard (and I don't think it is, especially if machine_parse is
centralized as in my reply to "[PATCH] vl.c: fix regression when reading
machine type from config file") the old semantics made more sense.

Paolo

> However, I think looking forward we'll want to spawn an XHCI adapter
> rather than OHCI. It's just a lot cheaper to emulate. But that's out of
> scope of this patch set.