Re: [BUG] virtio-net linux driver fails to probe on MIPS Malta since 'hw/virtio-pci: fix virtio behaviour'

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Mar 20, 2017 at 05:21:22PM +0200, Marcel Apfelbaum wrote:
> On 03/17/2017 11:57 PM, James Hogan wrote:
> > Hi,
> > 
> > I've bisected the following failure of the virtio_net linux v4.10 driver
> > to probe in QEMU v2.9.0-rc1 emulating a MIPS Malta machine:
> > 
> > virtio_net virtio0: virtio: device uses modern interface but does not have VIRTIO_F_VERSION_1
> > virtio_net: probe of virtio0 failed with error -22
> > 
> > To QEMU commit 9a4c0e220d8a ("hw/virtio-pci: fix virtio behaviour").
> > 
> > It appears that adding ",disable-modern=on,disable-legacy=off" to the
> > virtio-net -device makes it work again.
> > 
> > I presume this should really just work out of the box. Any ideas why it
> > isn't?
> > 
> 
> Hi,
> 
> 
> This is strange. This commit changes virtio devices from legacy to virtio "transitional".
> (your command line changes it to legacy)
> Linux 4.10 supports virtio modern/transitional (as far as I know) and on QEMU side
> there is nothing new.
> 
> Michael, do you have any idea?
> 
> Thanks,
> Marcel

My guess would be firmware mishandling 64 bit BARs - we saw such
a case on sparc previously. As a result you are probably reading
all zeroes from features register or something like that.
Marcel, could you send a patch making the bar 32 bit?
If that helps we know what the issue is.

> > Cheers
> > James
> > 
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization



[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux