James Harper
2008-Jul-04 05:13 UTC
[Xen-devel] differences in hvm save/restore in 3.1 vs 3.2
I''m still trying to figure out why save/restore was working with my windows gplpv drivers and suddenly now it''s not, and I''ve just realised that the one thing that has changed is that I''ve switched back to Xen 3.2 again, and when it was working I was using Xen 3.1. Are there any fundamental differences between how the HVM save/restore works between 3.1 and 3.2? It seems I can''t use the windows debugger to help me, as after I restore it will no longer reconnect, while it did when I was using Xen 3.1. That may be unrelated to the above problem though... the debugger connects to the serial port of the hvm domain via an ''xm console xxx'' command in inetd.conf... and I think that that isn''t working properly after the restore. Thanks James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
James Harper
2008-Jul-04 05:16 UTC
RE: [Xen-devel] differences in hvm save/restore in 3.1 vs 3.2
> > It seems I can''t use the windows debugger to help me, as after Irestore> it will no longer reconnect, while it did when I was using Xen 3.1.That> may be unrelated to the above problem though... the debugger connectsto> the serial port of the hvm domain via an ''xm console xxx'' command in > inetd.conf... and I think that that isn''t working properly after the > restore.Further to this, before the ''save'' is issued, ''xm console'' behaves how I would expect - nothing gets echo''s to the screen and ^] closes the console session. After the ''restore'', ''xm console'' echo''s everything to the screen, and ^] doesn''t do anything useful (apart from print ^] on the screen), like the console session hasn''t connected to the serial port at all. Any idea''s on that? Thanks James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Christopher Head
2008-Jul-04 06:56 UTC
Re: [Xen-devel] differences in hvm save/restore in 3.1 vs 3.2
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 There''s a bug in the serial port emulation in qemu related to saving and restoring. There''s a patch floating around somewhere which fixes it, but depending on what source tree you''re using you may not have it yet. One of the critical registers isn''t saved and also isn''t regenerated at restore time, meaning that serial port interrupts stop getting delivered to the guest properly. Chris James Harper wrote: |> It seems I can''t use the windows debugger to help me, as after I | restore |> it will no longer reconnect, while it did when I was using Xen 3.1. | That |> may be unrelated to the above problem though... the debugger connects | to |> the serial port of the hvm domain via an ''xm console xxx'' command in |> inetd.conf... and I think that that isn''t working properly after the |> restore. | | Further to this, before the ''save'' is issued, ''xm console'' behaves how I | would expect - nothing gets echo''s to the screen and ^] closes the | console session. After the ''restore'', ''xm console'' echo''s everything to | the screen, and ^] doesn''t do anything useful (apart from print ^] on | the screen), like the console session hasn''t connected to the serial | port at all. | | Any idea''s on that? | | Thanks | | James | | _______________________________________________ | Xen-devel mailing list | Xen-devel@lists.xensource.com | http://lists.xensource.com/xen-devel -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: GnuPT 2.7.2 Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkhtyYsACgkQiD2svb/jCb47kgCfS+6WHr8BKKeREuWY1hYatDDc ooQAmwbuVQ7pGCLCc1KXgoX93ztijzfW =Pw1D -----END PGP SIGNATURE----- _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
James Harper
2008-Jul-04 07:03 UTC
RE: [Xen-devel] differences in hvm save/restore in 3.1 vs 3.2
> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > There''s a bug in the serial port emulation in qemu related to savingand> restoring. There''s a patch floating around somewhere which fixes it,but> depending on what source tree you''re using you may not have it yet.One> of the critical registers isn''t saved and also isn''t regenerated at > restore time, meaning that serial port interrupts stop gettingdelivered> to the guest properly. >That sounds like the sort of problem I''m seeing. It''s obviously a regression though as it was working in 3.1. I''m using the Debian provided 3.2 packages but can easily apply a patch if I can find it... I''ll go searching tonight. Thanks James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Brendan Cully
2008-Jul-04 07:07 UTC
Re: [Xen-devel] differences in hvm save/restore in 3.1 vs 3.2
On Friday, 04 July 2008 at 17:03, James Harper wrote:> > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > There''s a bug in the serial port emulation in qemu related to saving > and > > restoring. There''s a patch floating around somewhere which fixes it, > but > > depending on what source tree you''re using you may not have it yet. > One > > of the critical registers isn''t saved and also isn''t regenerated at > > restore time, meaning that serial port interrupts stop getting > delivered > > to the guest properly. > > > > That sounds like the sort of problem I''m seeing. It''s obviously a > regression though as it was working in 3.1. > > I''m using the Debian provided 3.2 packages but can easily apply a patch > if I can find it... I''ll go searching tonight.It''s probably this one: http://xenbits.xensource.com/xen-unstable.hg/rev/13e10678e714 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
James Harper
2008-Jul-04 07:31 UTC
RE: [Xen-devel] differences in hvm save/restore in 3.1 vs 3.2
> > > > That sounds like the sort of problem I''m seeing. It''s obviously a > > regression though as it was working in 3.1. > > > > I''m using the Debian provided 3.2 packages but can easily apply apatch> > if I can find it... I''ll go searching tonight. > > It''s probably this one: > > http://xenbits.xensource.com/xen-unstable.hg/rev/13e10678e714 >I think that fixed it. Thanks. James _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel