Hello, Can HVM using SR-IOV live-migrate to the other Host and still in SR-IOV? If SR-IOV can, does Xen support it now? And if so, where is the code for it. Thanks. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Wed, 2011-11-02 at 06:07 -0400, software NJU wrote:> Hello, > Can HVM using SR-IOV live-migrate to the other Host and still in > SR-IOV? > If SR-IOV can, does Xen support it now? And if so, where is the code > for it.It is not possible to live migrate a guest which has a PCI device passed through to it. However you can use PCI hotplug to unplug a device right before migration and reintroduce another (possibly even different) device at the other end. This requires hotplug to be correctly configured in your guest to load the right drivers etc in response to hotplug events. Ian. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Thanks for your quick reply and great solution. However, I''m still not sure one thing: Do you mean that live migration is impossible because of hardware limitation? I''m reading the SR-IOV specification now. And it mentioned that a VF can migrate to another system through some kind of methods. But the migration may need the support of MR-IOV. What do you think of the saying in the specification? I''m not sure what the migration is in the specification. regards, 2011/11/2 Ian Campbell <Ian.Campbell@citrix.com>> On Wed, 2011-11-02 at 06:07 -0400, software NJU wrote: > > Hello, > > Can HVM using SR-IOV live-migrate to the other Host and still in > > SR-IOV? > > If SR-IOV can, does Xen support it now? And if so, where is the code > > for it. > > It is not possible to live migrate a guest which has a PCI device passed > through to it. > > However you can use PCI hotplug to unplug a device right before > migration and reintroduce another (possibly even different) device at > the other end. This requires hotplug to be correctly configured in your > guest to load the right drivers etc in response to hotplug events. > > Ian. > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Please don''t top post, see http://wiki.xen.org/xenwiki/AskingXenDevelQuestions On Wed, 2011-11-02 at 09:27 -0400, software NJU wrote:> Thanks for your quick reply and great solution. > However, I''m still not sure one thing: Do you mean that live migration > is impossible because of hardware limitation? I''m reading the SR-IOV > specification now. And it mentioned that a VF can migrate to another > system through some kind of methods. But the migration may need the > support of MR-IOV. > What do you think of the saying in the specification? I''m not sure > what the migration is in the specification.I''m afraid I don''t know precisely what the spec says here but (guessing) I suppose MR-IOV might allow you to ensure that you see the actual same device from two different host machines which would alleviate some of the problems associated with managing the hardware constraints when migrating. However I think in order to migrate with a piece of hardware attached somebody (either guest or tooling) would still need to know how to save the state of that specific device and restore it on the other end. Nothing in a Xen system today performs that function. I''m not sure that MR-IOV helps with that problem AFAIK. Ian. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel