Re: [RFC] libxl hotplug / unplug emulated devices

[Wei Liu <wei.liu2@citrix.com>]

On Mon, May 23, 2016 at 10:32:15AM +0100, George Dunlap wrote:
> On 20/05/16 18:45, Wei Liu wrote:
> > On Fri, May 20, 2016 at 05:38:44PM +0100, Ian Jackson wrote:
> >> Wei Liu writes ("[RFC] libxl hotplug / unplug emulated devices"):
> >>> Recently I got a report on xen-users@ about xl network-attach not
> >>> working for HVM guest.
> >>>
> >>> I try to use
> >>>   xl network-attach jessie-hvm 'bridge=xenbr0'
> >>> and vif-bridge script complains that it can't add vifXX-emu to bridge.
> >>>
> >>> The underlying issue is that the vif spec provided defaults to
> >>> emulated nic, but libxl only populates a pv nic but doesn't call out
> >>> via QMP to QEMU to populate one. Note that this issue not only affects
> >>> nic device but essentially all device types.
> >>
> >> Is it really sensible to offer emulated nic hotplug ?  That'd be
> >> presented to the guest as pci hotplug, I guess ?
> >>
> >>> I also experimented with block device:
> >>>   xl block-attach jessie-hvm 'phy:/dev/DATA/disk,hdb,w'
> >>> and it succeed, only pv disk is populated though.
> >>
> >> That's what I would have expected.
> >>
> >> Maybe the fix should be that xl network-attach should default hotplug
> >> nics to pv only.
> >>
> > 
> > Here is a patch to do this. :-)
> 
> Should we update the man page as well to clarify this?

Yes, I think if we only support plugging PV disk and nic we should make
that clear in man page.

I will prepare a separate patch for that.

Wei.

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel