WARNING - OLD ARCHIVES

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/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-ia64-devel

RE: [Xen-ia64-devel] xencons interrupt problem

To: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Subject: RE: [Xen-ia64-devel] xencons interrupt problem
From: Alex Williamson <alex.williamson@xxxxxx>
Date: Sun, 25 Jun 2006 21:42:30 -0600
Cc: xen-ia64-devel <xen-ia64-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Sun, 25 Jun 2006 20:42:44 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <386718549BA50E498DA75F3C0518CEEC0F1EE1@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-ia64-devel-request@lists.xensource.com?subject=help>
List-id: Discussion of the ia64 port of Xen <xen-ia64-devel.lists.xensource.com>
List-post: <mailto:xen-ia64-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=unsubscribe>
Organization: OSLO R&D
References: <386718549BA50E498DA75F3C0518CEEC0F1EE1@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Mon, 2006-06-26 at 11:27 +0800, Tian, Kevin wrote:
> I seem to understand your proposal now. Do you mean that some early 
> table will report the irq line information for the console device out of the 
> ACPI table?

Hi Kevin,

   Yes, the PCDP firmware table tells us all the details of the console
UART, base address, GSI, interrupt polarity/trigger, etc...  So we don't
need any additional ACPI/PCI knowledge to get the UART running in
interrupt mode.

>  If that's the case, I think changes required to achieve this 
> purpose is:
>       1. Modify assign_irq_vector hypercall to allow passing into GSI for 
> check sharing with PCI serial
>               If it's sharing, return existing vector instead of a new 
> allocation
>       2. Add a new flag to indicate such sharing between xen and dom0, 
> and remove checks against this style in all places.
>               When assertion on this irq line happens, pass to xen first and 
> then to dom0

   Great, this is what I was thinking too.  I'll try to look into adding
this.

>       3. Do we need to hide such console from dom0, since the latter 
> only uses para-virtualized xenconsole?

   This is a little tricky.  I think for now we'll likely use the same
CONFIG_XEN_DISABLE_SERIAL option that x86 uses to hide all the UARTs
from dom0.  Ideally we could hide them dynamically to allow a
transparent VP kernel to still use a serial console.  Thanks,

        Alex

-- 
Alex Williamson                             HP Open Source & Linux Org.


_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel