Re: [Qemu-devel] [RfC PATCH 1/3] net: macaddr tweaks.

[Gerd Hoffmann]

> > +void qemu_macaddr_default_if_unset(macaddr_t macaddr)
> > +{
> > +    macaddr_t zero = { 0,0,0,0,0,0 };
> > +
> > +    if (memcmp(macaddr, zero, sizeof(zero)) != 0)
> > +        return;
> > +    macaddr[0] = 0x52;
> > +    macaddr[1] = 0x54;
> > +    macaddr[2] = 0x00;
> > +    macaddr[3] = 0x12;
> > +    macaddr[4] = 0x34;
> > +    macaddr[5] = 0x56;
> > +}
> > +
>
> This will get us the same default MAC address for all NICs, won't it?
> The old code provides a different default for each NIC.
>
> Simply increment the default whenever it is used?

Would be an option.  Doesn't fully match the old behavior though.

Old behavior is to use 0x56 + nic index (i.e. nd_table index) for the 
last byte, so nic #1 allways has 0x57, no matter whenever for nic #0 a 
default was specified or not.

The problem we have here is that the nics created via -device don't have 
a nd_table entry and thus no nic index.  We have a related issue with 
pxe boot (-boot n,o,p,q == boot first,second,third,fourth nic).

Didn't have a good idea (yet) how to address that.

> > +typedef uint8_t macaddr_t[6];
>
> Reserved identifier (any POSIX header).  Do we care?

We should prrobably qemu-ify it to something like MACAddr anyway.

cheers,
  Gerd