Date: Tue, 23 Feb 2016 23:07:49 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-amd64@FreeBSD.org Subject: [Bug 207446] Hang bringing up vtnet(4) on >8 cpu GCE VMs Message-ID: <bug-207446-6-GoYWF4A1tH@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-207446-6@https.bugs.freebsd.org/bugzilla/> References: <bug-207446-6@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D207446 Jon Olson <jonolson@google.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jonolson@google.com --- Comment #4 from Jon Olson <jonolson@google.com> --- As far as I know we're compliance with the VIRTIO spec here. We do advertise max queues =3D=3D to number of vCPUs, but there is not requirement that a g= uest configure/use all of them to take advantage of multiqueue support. From the (draft) spec change introducing multi-queue (edited for readability from https://github.com/rustyrussell/virtio-spec/commit/67023431c8796bc430ec0a79= b15bab57e2e0f1f6):=20 """ Only receiveq0, transmitq0 and controlq are used by default. To use more qu= eues driver must negotiate the VIRTIO_NET_F_MQ feature; initialize up to `max_virtqueue_pairs` of each of transmit and receive queues; execute VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command specifying the number of the transm= it and receive queues that is going to be used and wait until the device consu= mes the controlq buffer and acks this command. """ This is what we do -- by default we service only rx0, tx0, and cq. Upon receiving VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET we will begin servicing the numbe= r of queues requested up to the value from the `max_virtqueue_pairs`. Larger val= ues (and zero) should be NAK'd by the virtual device (and no change in the numb= er of queue serviced will occur). If a guest kernel does not wish to use more than, e.g., 8 tx/rx virtqueue p= airs it need not configure more than the first eight and the control queue (alwa= ys at index 2*max_queue_pairs + 1, per the spec). As I said, I think we're in compliance with the spec here, but certainly if= not I'll treat it as a bug. --=20 You are receiving this mail because: You are on the CC list for the bug.=
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