Re: [Qemu-devel] qemu -netdev tun/tap support can't handle macvtap type devices

[Peter Maydell <peter.maydell@linaro.org>]

On 7 December 2016 at 12:04, Daniel P. Berrange <berrange@redhat.com> wrote:
> On Wed, Dec 07, 2016 at 12:01:14PM +0000, Peter Maydell wrote:
>> The usual suggested workaround is to use the -netdev fd option, like
>>   fd=3 3<>/dev/tap$(< /sys/class/net/tap0/ifindex)
>> (which gets the shell to open the right /dev/tap device).
>> Unfortunately this isn't compatible with multi-queue support
>> because netdev complains
>> "ifname=, script=, downscript=, vnet_hdr=, helper=, queues=, fds=,
>> and vhostfds= are invalid with fd="
>> so you can't pass options like "queues=4"...
>
> FWIW you should be able to instead do
>
>    fds=3 3<>/dev/tap$(< /sys/class/net/tap0/ifindex)
>
> note 'fds' plural, instead of 'fd'

What's the difference between that and the "usual suggested workaround"
I described above that doesn't work with queues=... ?

thanks
-- PMM