Re: [libvirt] More then one pci device possible with libvirt and pci passthrough?
Hi,
i tried some pci devices in windows guest, but there are some problems.
If i only use one pci card, i can install the driver in the guest and
the device is working.
If i want to use two or more pci devices in the guest, they are not
usable, it means i can install the
drivers, but the devices are not active in the device manager (yellow*
exclamation mark)*
If i install two ore more pci devices and pass through only one of them,
its also not usable in the
guest (yellow *exclamation mark)*
Exists there some limitations in the usage of "PCI Passthrough"?
(sorry for my bad english)
Greetings
Mirko
Hi Mirko,
On Sun, 2009-06-28 at 17:46 +0200, Mirko Raasch wrote:
> Hi,
>
> i want to use more then one pci card in my debian guest.
>
> But when i start the guest, the log says:
>
> libvirtd: 15:44:55.459: warning : pciTrySecondaryBusReset:483 : Other
> devices on bus with 0000:05:01.0, not doing bus reset
>
> With "/usr/bin/qemu-system-x86_64 -m 512 -name test -hda
> /media/vm/test.img -boot c -vnc :2 -k de -pcidevice host=05:01.0
> -pcidevice host=05:02.0 -pcidevice host=05:03.0" there seems to be no
> problems.
>
I'm afraid this is purely a limitation with the current code in qemu:
/* For now, we just refuse to do a secondary bus reset
* if there are other devices/functions behind the bus.
* In future, we could allow it so long as those devices
* are not in use by the host or other guests.
*/
if (pciBusContainsOtherDevices(conn, dev)) {
VIR_WARN("Other devices on bus with %s, not doing bus reset",
dev->name);
return -1;
}
We also have a bug tracking this issue:
https://bugzilla.redhat.com/499678
Fixes welcome! :-)
Cheers,
Mark.