Re: [Qemu-devel] [PATCH v2] e1000: pre-initialize RAH/RAL registers

[Stefan Hajnoczi]

On Wed, Oct 31, 2012 at 02:15:39PM -0400, Gabriel L. Somlo wrote:
> Some guest operating systems' drivers (Mac OS X in particular) fail to
> properly initialize the Receive Address registers (probably expecting
> them to be pre-initialized by an earlier component, such as a specific
> proprietary BIOS). This patch pre-initializes the RA registers, allowing
> OS X networking to function properly. Other guest operating systems are
> not affected, and free to (re)initialize these registers during boot.
> 
> Signed-off-by: Gabriel Somlo <address@hidden>
> ---
> 
> On Wed, Oct 31, 2012 at 09:03:51AM +0100, Stefan Hajnoczi wrote:
> > Please use 4 space indentation (QEMU coding style).
> 
> My bad, fixed in this version.
> 
> > > +  memmove(&d->mac_reg[RA], &d->conf.macaddr, sizeof(struct MACAddr));
> >
> > When the host is big-endian the filter code will byteswap and the MAC 
> > address
> > will not match:
> > 
> >   for (rp = s->mac_reg + RA; rp < s->mac_reg + RA + 32; rp += 2) {
> >       if (!(rp[1] & E1000_RAH_AV))
> >           continue;
> >       ra[0] = cpu_to_le32(rp[0]);
> >       ra[1] = cpu_to_le32(rp[1]);
> >       if (!memcmp(buf, (uint8_t *)ra, 6)) {
> 
> OK, I guess I could just memmove from d->eeprom_data instead of
> d->conf.macaddr.a, on the assumption that pci_e1000_init() already
> did the endian-proofing for me. But probably the safest/most paranoid
> method is best, see below...
> 
> Thanks,
>   Gabriel
> 
>  hw/e1000.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)

Although real hardware doesn't behave like this we can probably get away
with it.  I will test Linux and Windows guests with e1000 for the QEMU
1.3 release - if we run into problems this patch may be reverted.

Thanks, applied to the net tree:
https://github.com/stefanha/qemu/commits/net

Stefan