Re: [Xen-users] Serial Passthrough broken in Debian Wheezy?

[Jonas Meurer <jonas@xxxxxxxxxxxxxxx>]

Hello,

did anybody else discover issue with serial passthrough on Linux 3.2.0 
from Debbian Wheezy?
Kind redgards,
 jonas


Am 2013-05-14 14:56, schrieb Jonas Meurer:
> Hey again,
>
> Am 13.05.2013 17:58, schrieb Jonas Meurer:
> > I just discovered a strange bug with serial passthrough in xen 4.1 on
> > Debian Wheezy. The Dom0 has a GSM modem connected to serial port. The
> > serial port is passed through to a DomU with options 'irq = [ 4 ]' and
> > 'ioports = [ '3f8-3ff ]'.
> While searching the list archives I found out, that latest Xen 4.1 has
> several issues with passthrough. But so far it seems to me like nobody
> else described my exact issue before. Apparently, the other passthrough
> issues have been introduced by a hypervisor update. My problem appeared
> after a kernel upgrade. And for me, DomU creation still works. As
> described, the passed through serial even exists in DomU. Only it
> doesn't behave as expected.
>
> Just wanted to share those additional observations.
>
> Kind regards,
>  jonas
>
> > This worked as expected on Debian Squeeze with Xen 4.0 and Linux 
> > kernel
> > 2.6.32 (both for Dom0 and DomU). On Debian Wheezy with Xen 4.1 and
> > Linux kernel 3.2.0 the passthrough seems to work as well (/dev/ttyS0
> > appears in dmesg of DomU), but something is wrong. The GSM modem
> > doesn't behave as expected. The smstools daemon errors out with 
> > 'Cannot
> > open serial port /dev/ttyS0, error: Function not implemented'.
> >
> > It took me hours to find the difference, but it seems like the guest
> > (domU) kernel is the problem. The setup keeps working when Dom0 is
> > upgraded to Debian Wheezy with Xen 4.1 and linux kernel 3.2.0. It even
> > keeps working if the DomU userland is upgraded to Debian Wheezy. Only
> > if I upgrade the DomU linux kernel to 3.2.0 from Wheezy as well,
> > smstools stops working.
> >
> > I don't expect this to be a smstools bug. More likely, something
> > regarding serial pass through functions of xen is broken in 3.2.0
> > kernel from Debian Wheezy.
> >
> > Did anybody else discover similar issues yet?
> >
> > Kind regards,
> >  jonas
> >
> > PS: I'm not subscribed to pkg-xen-devel@xxxxxxxxxxxxxxxxxxxxxxx, 
> > please
> > cc me on that list.
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@xxxxxxxxxxxxx
> > http://lists.xen.org/xen-users
>
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