Hello everyone, just wondered after I read about devices passed through in HVM if the following if still true: (for Xen3.2.1) - a Domain running in HVM cannot get forwarded any other device than a USB device. - the USB device forwarding is not too stable - PCI forwarding is not possible without processor support and Xen support. - The GPLPV tools won''t change anything with that. Because if forwarding PCI devices to Xen HVM DomU would be possible that would be highly cool because it would enable me to use a PCIe-card that is definitly not supported with Linux in a Windows DomU where it is supported quite well. Thanks a lot for your information refresh :D Regards Joti _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, Jun 16, 2008 at 08:31:00PM +0200, Joti Mail wrote:> Hello everyone, > > just wondered after I read about devices passed through in HVM if the > following if still true: (for Xen3.2.1) > > - a Domain running in HVM cannot get forwarded any other device than a > USB device. > - the USB device forwarding is not too stable > - PCI forwarding is not possible without processor support and Xen support.Yes, you need VT-d support in your CPU/chipset.. and in Xen.> - The GPLPV tools won''t change anything with that. >GPLPV drivers won''t help with that.. that''s true. but they might make it more difficult (GPLPV drivers might hide too many devices, ie. not just the QEMU devices, but also VT-d pasthrough devices..)> Because if forwarding PCI devices to Xen HVM DomU would be possible that > would be highly cool because it would enable me to use a PCIe-card that > is definitly not supported with Linux in a Windows DomU where it is > supported quite well. > > Thanks a lot for your information refresh :D >-- Pasi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> just wondered after I read about devices passed through in HVM if the > following if still true: (for Xen3.2.1) > > - a Domain running in HVM cannot get forwarded any other device than a > USB device. > - the USB device forwarding is not too stable > - PCI forwarding is not possible without processor support and Xen > support. > - The GPLPV tools won''t change anything with that.The GPLPV drivers need to hide/disable the qemu network and disk devices. If the network devices are not disabled I found that dom0''s network would break for a few seconds. If the disk devices are not disabled then your DomU filesystem gets corrupted. Corrupted badly enough that the only option is a restore or rebuild. Previous versions of the GPLPV drivers ''hid'' the qemu devices by preventing their enumeration, but for reasons unknown this didn''t work on some platforms. The current version installs itself as a ''filter'' driver for all disk (ide and scsi) and network devices. When GPLPV is not specified, the filter fails the ''start'' irp for devices on the ''xen bus''. When GPLPV is specified the filter fails the ''start'' irp for devices on the pci bus. If your PCI passthrough device reports itself as an ide, scsi, or network device, then the xenhide filter will not allow it to start. I have at least one report of a dvb card reporting itself as a network device (maybe they all do this?) so it will be blocked when gplpv is specified. I''m considering my options on ways to get around this at the moment... James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > Because if forwarding PCI devices to Xen HVM DomU would be possiblethat> would be highly cool because it would enable me to use a PCIe-cardthat> is definitly not supported with Linux in a Windows DomU where it is > supported quite well. >I''m still considering the different ways of achieving this... can you please go into device manager and open the device you have passed through (with or without /gplpv, doesn''t matter). I want to know what it says next to Location. All the qemu PCI devices appear to be on PCI bus 0. If pass-through''d devices are on a different PCI bus then the problem can be solved easily. James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> just wondered after I read about devices passed through in HVM if the > following if still true: (for Xen3.2.1) > > - a Domain running in HVM cannot get forwarded any other device than a > USB device.Correct.> - the USB device forwarding is not too stableI''ve heard variable reports about this; it''s been a while since I''ve heard anything, which is sometimes a good thing :-)> - PCI forwarding is not possible without processor support and Xen support.For a PV guest you can do PCI forwarding without special hardware (but you have to trust that guest because abusing the PCI device could make it as powerful as dom0, with the ability to do anything on the machine). For an HVM guest you need more than just processor support: for VT-d you currently need chipset support. You need a Xen which can make use of the VT-d hardware, too. The guest would not have to be Xen-aware or have any Xen additions installed into it, however.> - The GPLPV tools won''t change anything with that. > > Because if forwarding PCI devices to Xen HVM DomU would be possible that > would be highly cool because it would enable me to use a PCIe-card that > is definitly not supported with Linux in a Windows DomU where it is > supported quite well.I''m afraid that won''t be possible for the moment. Some guys at a company called Neocleus were working on passing through PCI devices (I think they were focused on graphics) to HVM guests without special hardware but I''ve not heard anything about this effort for a while so I don''t know if it''s still going. Cheers, Mark> Thanks a lot for your information refresh :D > > Regards > Joti > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users-- Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > Some guys at a company called Neocleus were working on passing through PCI > devices (I think they were focused on graphics) to HVM guests without > special > hardware but I''ve not heard anything about this effort for a while so I > don''t > know if it''s still going.some news on this company at least: http://www.virtualization.info/2008/06/neocleus-secures-11-million-in-series-b.html Cheers, Todd _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users