On Tue, May 21, 2019 at 09:21:57AM +0200, Jens Freimann wrote: > On Mon, May 20, 2019 at 04:56:57PM -0600, Alex Williamson wrote: > > On Fri, 17 May 2019 14:58:16 +0200 > > Jens Freimann <jfreim...@redhat.com> wrote: > > > Command line example: > > > > > > qemu-system-x86_64 -enable-kvm -m 3072 -smp 3 \ > > > -machine q35,kernel-irqchip=split -cpu host \ > > > -k fr \ > > > -serial stdio \ > > > -net none \ > > > -qmp unix:/tmp/qmp.socket,server,nowait \ > > > -monitor telnet:127.0.0.1:5555,server,nowait \ > > > -device > > > pcie-root-port,id=root0,multifunction=on,chassis=0,addr=0xa \ > > > -device pcie-root-port,id=root1,bus=pcie.0,chassis=1 \ > > > -device pcie-root-port,id=root2,bus=pcie.0,chassis=2 \ > > > -netdev > > > tap,script=/root/bin/bridge.sh,downscript=no,id=hostnet1,vhost=on \ > > > -device > > > virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:6f:55:cc,bus=root2,failover=on > > > \ > > > /root/rhel-guest-image-8.0-1781.x86_64.qcow2 > > > > > > Then the primary device can be hotplugged via > > > (qemu) device_add > > > vfio-pci,host=5e:00.2,id=hostdev0,bus=root1,standby=net1 > > > > Is this standby= option only valid for Network/Ethernet class code > > devices? If so, perhaps vfio-pci code should reject the option on any > > non-ethernet devices. The option is also non-intuitive for users, only > > through examples like above can we see it relates to the id of the > > secondary device. Could we instead name it something like > > "standby_net_failover_pair_id="? > > It is only for ethernet (VFs), I will add code to reject non-ethernet VF > devices. > I agree the name is not descriptive and the one you suggest seems good to > me. > > > > Also, this feature requires matching MAC addresses per the description, > > where is that done? Is it the user's responsibility to set the MAC on > > the host device prior to the device_add? If so, is this actually not > > only specific to ethernet devices, but ethernet VFs? > > Yes, it's the users responsibility and the MACs are then matched by > the net_failover driver in the guest. It makes sense for ethernet VFs only, > I'll add a check for that.
Actually is there a list of devices for which this has been tested besides mlx5? I think someone said some old intel cards don't support this well, we might need to blacklist these ... > > > > Finally, please copy me on code touching vfio. Thanks, > > I'm sorry about that, will do. > > Thanks for the review Alex! > > regards, > Jens
