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


Re: [Xen-devel] HVM with old kernel(rh5.1) assigned device resume failur

To: "Ke, Liping" <liping.ke@xxxxxxxxx>
Subject: Re: [Xen-devel] HVM with old kernel(rh5.1) assigned device resume failure because of restore sequence
From: Yuji Shimada <shimada-yxb@xxxxxxxxxxxxxxx>
Date: Fri, 17 Apr 2009 15:58:49 +0900
Cc: "Xen-Devel \(E-mail\)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 16 Apr 2009 23:59:27 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <E2263E4A5B2284449EEBD0AAB751098401CFD2667E@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
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>
References: <E2263E4A5B2284449EEBD0AAB751098401CFD2667E@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Fri, 17 Apr 2009 10:32:31 +0800
"Ke, Liping" <liping.ke@xxxxxxxxx> wrote:

> Older kernel(before 2.6.18 in rh5.1) cmd register is restored before Bar 
> register,
> it will cause qemu passthrough pt_mapping_bars failure.
> (In qemu, pt_bar_mappings is done in pt_cmd_reg_write. pt_bar_reg_write is 
> not performed
> yet, then pt_bar_mappings can't map the correct address)
> Latest kernel (after 2.6.2X) has no such problem. (When do pt_bar_mapping in 
> pt_cmd_reg_write,
> pt_bar_reg_write is already done).
> I pasted corrected Qemu(2.6.29) log (line 660) and uncorrected Qemu(rh5.1) 
> Log (Line 554)
> and add [ criping XXX] comments for your reference.
> For supporting old kernel, could we consider to change the pt_bar_mappings 
> sequence in Qemu?
> We'd like to have your opinions first.

The following modification is required.

  When pt_bar_reg_write is called, it should call pt_bar_mapping if
  memory space bit or IO space bit in command register is '1'.

As a result IO/memory resource is mapped at the correct address.

Yuji Shimada

Xen-devel mailing list