Re: [Qemu-devel] [PATCH 4/4] kvm: i386: Add classic PCI device assignment

[Blue Swirl]

On Tue, Aug 28, 2012 at 5:28 PM, Michael S. Tsirkin <address@hidden> wrote:
> On Tue, Aug 28, 2012 at 05:01:55PM +0000, Blue Swirl wrote:
>> On Tue, Aug 28, 2012 at 7:35 AM, Michael Tokarev <address@hidden> wrote:
>> > On 27.08.2012 22:56, Blue Swirl wrote:
>> > []
>> >>> +static uint32_t slow_bar_readb(void *opaque, target_phys_addr_t addr)
>> >>> +{
>> >>> +    AssignedDevRegion *d = opaque;
>> >>> +    uint8_t *in = d->u.r_virtbase + addr;
>> >>
>> >> Don't perform arithmetic with void pointers.
>> >
>> > There are a few places in common qemu code which does this for a very
>> > long time.  So I guess it is safe now.
>>
>> It's a non-standard GCC extension.
>
> So?  We use many other GCC extensions. grep for typeof.

Dependencies should not be introduced trivially. In this case, it's
pretty easy to avoid void pointer arithmetic as Jan's next version shows.

>
> Is there a work in progress to build GCC with visual studio?
> If yes what are the chances KVM device assignment
> will work on windows?

IIRC there was really a project to use KVM on Windows and another
project to build QEMU with MSVC.

>
> Look QEMU codebase is what it is. Unless you rework all existing
> code to confirm to your taste, I do not see why you NACK valid new code
> unless it confirms to same.

Yes, I'd be happy to fix the style with huge patches at once. But our
fearless leader does not agree, so we are stuck with the codebase
being what it is until it is fixed one step at a time.

>
>> >
>> > /mjt