This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] Passthrough of Serial port /dev/ttyS0 to PV and HVM domains

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] Passthrough of Serial port /dev/ttyS0 to PV and HVM domains problems
From: "Linux@xxxxxxxxxxxxxx" <linux@xxxxxxxxxxxxxx>
Date: Tue, 7 Apr 2009 18:16:20 +0200
Delivery-date: Tue, 07 Apr 2009 09:16:58 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Organization: Eikelenboom IT services
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
I'm trying to get the following working:

Serial port (/dev/ttyS0) passthrough to a PV or HVM domain, together with
xenfb and usb passthrough.

passthrough of the serial port works fine in a PV without xenfb (and so
without qemu) by using the following lines in the config:

        irq = [4]
        ioports = ["3f8-3ff"]

by using
        vfb = [ 'vnc=1,vnclisten=,vncunused=1' ]
it will use qemu, so the lines above don't work anymore.

Now it uses qemu which is the same for HVM and PVM

using   serial='/dev/ttyS0' in the config files doesn't work, although it 
should according to
the qemu manpages.
    echo "test" > /dev/ttyS0
on the host,and
    cat /dev/ttyS0
on the guest, to test it, it shows nothing on the guest

when using serial=pty in the config file, and using
    echo "test" > /dev/pts/0
on the host,and
    cat /dev/ttyS0
on the guest, to test it, it shows the test string on the guest

socat /dev/ttyS0 /dev/pts/0 works passing through the hardware serial port
to the guest, but it's not very elegant since the pts/0 could change.

- Shouldn't the serial='/dev/ttyS0' config option work in the first place
for the qemu domains (PV or HVM) ?

- is xenfb and thus x11 support indeed only available on PV's using qemu ?

- is there any other way to get sdl/vnc graphics in a domU together with
serial port passthrough, without using external tools as socat ?

- wouldn't it be nice to have some sort of standardization in all the
available passthrough options, or at least an overview in Dom0 of what is
passthrouged to what in the different guest domains.
There are quite a few variables at the moment:
          -xend-PV or qemu-PV/HVM.
          -PCI or USB or serial or parport passthrough.
          -with or without VT-D/iommu support.
And it is difficult to find out the status (working/partially/not-working)
of all these options it leads to. It also means there is not much
documentation around.

I hope anyone can help ...


Sander Eikelenboom

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>