[PATCH] qemu: do not add model when actual iface type is hostdev

Boris Fiuczynski fiuczy at linux.ibm.com
Wed Jun 17 16:55:20 UTC 2020

On 6/17/20 6:01 AM, Laine Stump wrote:
> On 6/16/20 10:32 AM, Paulo de Rezende Pinatti wrote:
>> No default model should be added to the interface
>> entry at post parse when its actual network type is hostdev
>> as doing so might cause a mismatch between the interface
>> definition and its actual device type.
> Have you encountered a real problem from this? (I have, and have been 
> thinking about the issue for awhile, but only late at night when I'm not 
> near my keyboard to do something about it. I'm just wondering what 
> problem you've had :-))
> The reason it's been on my mind is this: The default model is rtl8139. 
> When libvirt is auto-assigning PCI addresses to devices at parse time, 
> it decides whether to assign a network device to a conventional PCI or 
> PCI Express slot based on the model, and rtl8139 is conventional PCI. So 
> if you have <interface type='network'> where the network is a pool of 
> hostdevs, and if you don't assign a "fake" model like "virtio" or 
> "e1000e", then the hostdev device (which is 100% certainly a PCIe 
> device) will be assigned to a conventional PCI slot. That works, but 
> is.... "sub-optimal" :-)
> I think we will still need to add a bit to 
> qemuDomainDeviceCalculatePCIConnectFlags() in order to get the right 
> type of slot set, but this is a good start.
> Reviewed-by: Laine Stump <laine at redhat.com>
> Thanks, and congratulations on your first libvirt patch!

Hi Laine,
do you plan to push this patch?

Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Gregor Pillen
Geschäftsführung: Dirk Wittkopp
Sitz der Gesellschaft: Böblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294

More information about the libvir-list mailing list