[libvirt] Changing device owner
Alex, Regarding vdsm changing a device owner, Last time I asked in #virt for using usb device in vdsm hook in /dev/bus/usb/<addr> I was told that vdsm should change the owner to qemu:kvm. So for the sr-iov device /sys/bus/pci/devices/<addr>/resource*, rom, and reset libvirt should change the owner and not vdsm? Shahar Havivi.
On Sat, 2011-07-30 at 12:12 +0300, Shahar Havivi wrote:
Alex,
Regarding vdsm changing a device owner, Last time I asked in #virt for using usb device in vdsm hook in /dev/bus/usb/<addr> I was told that vdsm should change the owner to qemu:kvm. So for the sr-iov device /sys/bus/pci/devices/<addr>/resource*, rom, and reset libvirt should change the owner and not vdsm?
I'm not in any position to say who should do what between vdsm and libvirt. However, the end result for device assignment to work with an unprivileged guest is that someone needs to change file ownership on those pci sysfs files before qemu is launched or before devices are hot added to a guest. libvirt does this for a purely libvirt managed guest. In the example we saw yesterday, nobody was doing it. Thanks, Alex
On 30.07.11 07:20, Alex Williamson wrote:
On Sat, 2011-07-30 at 12:12 +0300, Shahar Havivi wrote:
Alex,
Regarding vdsm changing a device owner, Last time I asked in #virt for using usb device in vdsm hook in /dev/bus/usb/<addr> I was told that vdsm should change the owner to qemu:kvm. So for the sr-iov device /sys/bus/pci/devices/<addr>/resource*, rom, and reset libvirt should change the owner and not vdsm?
I'm not in any position to say who should do what between vdsm and libvirt. However, the end result for device assignment to work with an unprivileged guest is that someone needs to change file ownership on those pci sysfs files before qemu is launched or before devices are hot added to a guest. libvirt does this for a purely libvirt managed guest. In the example we saw yesterday, nobody was doing it. Thanks,
Alex Ok, as far as I know vdsm need to change its devices. in our sr-iov example you change the reset and the resource* owner, did you change any other file?
On Sat, 2011-07-30 at 17:19 +0300, Shahar Havivi wrote:
On 30.07.11 07:20, Alex Williamson wrote:
On Sat, 2011-07-30 at 12:12 +0300, Shahar Havivi wrote:
Alex,
Regarding vdsm changing a device owner, Last time I asked in #virt for using usb device in vdsm hook in /dev/bus/usb/<addr> I was told that vdsm should change the owner to qemu:kvm. So for the sr-iov device /sys/bus/pci/devices/<addr>/resource*, rom, and reset libvirt should change the owner and not vdsm?
I'm not in any position to say who should do what between vdsm and libvirt. However, the end result for device assignment to work with an unprivileged guest is that someone needs to change file ownership on those pci sysfs files before qemu is launched or before devices are hot added to a guest. libvirt does this for a purely libvirt managed guest. In the example we saw yesterday, nobody was doing it. Thanks,
Alex Ok, as far as I know vdsm need to change its devices. in our sr-iov example you change the reset and the resource* owner, did you change any other file?
No, and I don't think the "resource" file is necessary, the default read access should be sufficient. We need resource[0-5], rom, and reset (any given device will likely only implement a subset of these). We also access config, but that happens via the pre-opened file descriptor. Thanks, Akex
participants (2)
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Alex Williamson -
Shahar Havivi