Jiang, Yunhong
2010-Sep-08 14:36 UTC
[Xen-devel] Checkpointing for HVM guest with PV driver
Hi, Brendan, I noticed following code in checkpoint_open() in tools/python/xen/lowlevel/checkpoint/libcheckpoint.c: } else if (s->domtype == dt_pvhvm) { checkpoint_close(s); s->errstr = "PV-on-HVM is unsupported"; return -1; } This check means for HVM guest with PV driver, the checkpoint/remus will not work. Are there any special reason for this checking? Originally I thought PV driver on HVM guest can''t live migrate, but I did a quick experimental to live migration a HVM guest with PV driver installed, (I only tried to migrate to localhost since I have only one system on hand) and seems it works well, so what''s the reason for this restriction? Thanks --jyh _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Brendan Cully
2010-Sep-08 16:38 UTC
Re: [Xen-devel] Checkpointing for HVM guest with PV driver
On Wednesday, 08 September 2010 at 22:36, Jiang, Yunhong wrote:> Hi, Brendan, I noticed following code in checkpoint_open() in tools/python/xen/lowlevel/checkpoint/libcheckpoint.c: > > } else if (s->domtype == dt_pvhvm) { > checkpoint_close(s); > s->errstr = "PV-on-HVM is unsupported"; > > return -1; > } > > This check means for HVM guest with PV driver, the checkpoint/remus will not work. Are there any special reason for this checking? > > Originally I thought PV driver on HVM guest can''t live migrate, but I did a quick experimental to live migration a HVM guest with PV driver installed, (I only tried to migrate to localhost since I have only one system on hand) and seems it works well, so what''s the reason for this restriction?It simply hasn''t been tested. I haven''t looked at how suspend notification/cancellation works in the PVHVM drivers, or whether it affects ioemu at all. If live migration works already, then there probably isn''t much to it. Have you tried removing that check and making checkpoint treat PVHVM the same as HVM, then running remus? _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel