Hi all, I could see some patches are submitted to support PV domain pass-through hotplug. So my question is, if we pci-detach all pci devices from domU, then can we able to migrate such a domain? regards, Masroor _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Hi, Masroor Vettuparambil wrote:> I could see some patches are submitted to support PV domain pass-through > hotplug. > So my question is, if we pci-detach all pci devices from domU, then can > we able to migrate such a domain?Yes, we can. And I think it is one of the important features of pci pass-throughn hotplug. Regards, ------------------- Yosuke Iwamatsu NEC Corporation _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Masroor Vettuparambil
2008-Mar-14 11:14 UTC
RE: [Xen-devel] question on PV pass-through patch
I tried your patch with CONFIG_XEN_PCIDEV_BACKEND_VPCI. Detached the pci on the source and attached another slot to migrated domU on destination. Migration is happening smoothly. thanks for your work. a minor thing I noticed is, dmesg on domU shows the following warning during pci-detach, WARNING: g.e. still in use! WARNING: leaking g.e. and page still in use! I wonder if we can achieve a ''live'' migration of direct access, ie, without interrupting the network traffic? Something like creating a vif(network-attach) on domU for carrying the n/w traffic temporarily till the migration is over. After migration, move the n/w traffic back from vif to newly pci-attached NIC on the destination. Any thought? regards, Masroor -----Original Message----- From: Yosuke Iwamatsu [mailto:y-iwamatsu@ab.jp.nec.com] Sent: Monday, March 10, 2008 7:07 AM To: Masroor Vettuparambil Cc: xen-devel@lists.xensource.com Subject: Re: [Xen-devel] question on PV pass-through patch Hi, Masroor Vettuparambil wrote:> I could see some patches are submitted to support PV domain > pass-through hotplug. > So my question is, if we pci-detach all pci devices from domU, then > can we able to migrate such a domain?Yes, we can. And I think it is one of the important features of pci pass-throughn hotplug. Regards, ------------------- Yosuke Iwamatsu NEC Corporation _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Masroor Vettuparambil wrote:> > I tried your patch with CONFIG_XEN_PCIDEV_BACKEND_VPCI. > Detached the pci on the source and attached another slot to migrated > domU on destination. > Migration is happening smoothly. thanks for your work. > > a minor thing I noticed is, dmesg on domU shows the following warning > during pci-detach, > WARNING: g.e. still in use! > WARNING: leaking g.e. and page still in use!I''m not sure what this means, but it looks like something is wrong with the disconnect procedure of pcifront/pciback.> I wonder if we can achieve a ''live'' migration of direct access, ie, > without interrupting the network traffic? > Something like creating a vif(network-attach) on domU for carrying the > n/w traffic temporarily till the migration is over. > After migration, move the n/w traffic back from vif to newly > pci-attached NIC on the destination. > Any thought?Actually I''ve been thinking of "passthrough domain live migration" using a multipath-driver which combines a passthrough device and a virtual device. Below is an idea of live migrating a domU which has passthrough network device attached. - First create bond0 and add the passthrough interface to it. - Usually we use the passthrough interface (fast path). - Before migration, attach a vif to the domU and add the vif interface to bond0. Then remove the passthrough inteface from bond0 and do pci-detach. We can migrate without network disconnection because the vif is now enabled (slow path). - After migration, do pci-attach, add passthrough interface to bond0, and disconnect the vif interface (switch back to fast path). I hope this method works, but I haven''t have an opportunity to try it myself yet. Thanks, ------------------- Yosuke Iwamatsu NEC Corporation _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel