Re: [Qemu-devel] [Xen-devel] [PATCH V11 3/8] Introduce XenHostPCIDevice to access a pci device on the host.

[Anthony PERARD]

On 16/05/12 12:24, Konrad Rzeszutek Wilk wrote:
> On Tue, Apr 03, 2012 at 04:32:38PM +0100, Anthony PERARD wrote:
> > Signed-off-by: Anthony PERARD<address@hidden>
>
> Looks good, thought I've just couple of tiny comments:
>
> > +#define XEN_HOST_PCI_RESSOURCE_BUFFER_SIZE 512
>
> You might want a comment explaining why 512, and not
> a more precise number like 741.

Actually, I only need the first 7 line of the resources file. So this 
is 399 bytes. I just add a little bit more.

> > +{
> .. snip..
> > +    do {
> > +        rc = read(fd,&buf, sizeof (buf) - 1);
> > +        if (rc<  0&&  errno != EINTR) {
> > +            rc = -errno;
> > +            goto out;
> > +        }
> > +    } while (rc<  0);
>
> Ok, you read it in. Maybe my 'wc' magic is gone, but this
> is what I get:
> address@hidden 0000:00:02.0]# cat resource | wc -c
> 741
> .. snip..
> > +#define XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE 42
>
> The answer to the life? Can you provide a comment explaining
> the reason why it is 42, please?

I just define more than needed, and 42 is a good number :-).
But the maximum I need is probably 7 (for example '0x8086\n', for a 
vendor id). Or 20, number of digit in LONG_MAX, base 10.

> > +static int xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
> > +                                  unsigned int *pvalue, int base)
> > +{


--
Anthony PERARD