Re: [Xen-devel] Xen, IRQ-sharing and PCI passthrough

[Florian Wagner <f_wagner@xxxxxxxxxx>]

> Assuming your kernel has a call to irq_ignore_unhandled() out of
> note_interrupt(), [...]

Judging from my backtrace this seems to be the case, right?


> [...] there's nothing but using hardware's help (i.e. VT-d
> interrupt remapping) to get this addressed: The pv passthrough
> mechanism assumes that guests you assign physical devices to are well
> behaved, and your guest isn't (it fails to disable the interrupt at
> the device).

Do I understand this correctly: For safe operation of a virtual machine
using PCI passthrough and shared interrupts a well behaved operating
system in the vm is necessary. That is an OS that shuts down the mapped
devices correctly before turning off (unload kernel module).

So what am I to to in the case that someone issues a "xm destroy" on
such a vm? There is no way to cleanly shutdown in such a situation, is
there?

That's quite a risk for system stability of the host. One thoughtless
"xm destroy" and the whole host is crashed, requiring at a minimum a
cold reset or even a reinstall.


Regards
Florian

--------------

Florian Wagner
Abteilung EDV
Telefon: 0821 / 4201 - 453
Fax: 0821 / 4201 - 411
E-Mail: f_wagner@xxxxxxxxxx

Syscomp Biochemische Dienstleistungen GmbH
August-Wessels-StraÃe 5, 86154 Augsburg
Postfach 102506, 86015 Augsburg
Telefon: 0821 / 4201 - 0
Fax: 0821 / 417992
Web: http://www.syscomp.de
E-Mail: syscomp@xxxxxxxxxx

GeschÃftsfÃhrer:
  Dr. med. Bernd Schottdorf
  Gabriele Schottdorf

Registergericht Augsburg HRB 8670

Attachment: signature.asc
Description: PGP signature

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel