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-devel

Re: [Xen-devel] RE: [Question] Do we need to support devices that do not

To: "Shan, Haitao" <haitao.shan@xxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] RE: [Question] Do we need to support devices that do not strictly follow the PCI-e specification?
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 09 Oct 2008 10:49:14 +0100
Cc: "Tian, Kevin" <kevin.tian@xxxxxxxxx>, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>, "Huang, Zhiteng" <zhiteng.huang@xxxxxxxxx>, "Li, Xin B" <xin.b.li@xxxxxxxxx>
Delivery-date: Thu, 09 Oct 2008 02:49:39 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <F6473715D25C9E46A5515027E5482F100919B017D3@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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Ackp6Pxc5rudKW6OT2KzDB9oYO0xLAABM7ZtAAAZrHAAANBIQAAAtaQ0
Thread-topic: [Xen-devel] RE: [Question] Do we need to support devices that do not strictly follow the PCI-e specification?
User-agent: Microsoft-Entourage/11.4.0.080122
Will do.

 K.


On 9/10/08 10:31, "Shan, Haitao" <haitao.shan@xxxxxxxxx> wrote:

Hi, Keir,
 
There is already a fix for calculating the size of PCI-e capability properly. The changeset is 77fba269. But this changeset is not in xen-3.3-testing. Can you help to check in that changeset to xen-3.3-testing tree?
Thanks!
 
Shan Haitao
 


From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Shan, Haitao
Sent: 2008
109 17:08
To: Keir Fraser; xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: Huang, Zhiteng; Tian, Kevin; Jiang, Yunhong; Li, Xin B
Subject: [Xen-devel] RE: [Question] Do we need to support devices that do not strictly follow the PCI-e specification?

Oh, I made some mistakes. I have just checked PCI-e 1.1 spec. It seems the definition of this capability structure is different with PCI-e 2.0. I will check more and find a solution.
 


From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx]
Sent: 2008
109 17:03
To: Shan, Haitao; xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: Jiang, Yunhong; Li, Xin B; Tian, Kevin; Huang, Zhiteng
Subject: Re: [Question] Do we need to support devices that do not strictly follow the PCI-e specification?




On 9/10/08 09:28, "Shan, Haitao" <haitao.shan@xxxxxxxxx> wrote:
Hi, Keir,
 
When debugging recently, I found some devices that did not follow the PCI-e specification strictly. Below is an example.

From PCI-e spec, PCI-e capability occupies 0x3c bytes of configuration space. Unimplemented registers are reserved and hardwired to zero. But for device listed below, PCI-e capability should begin at 0x4C and end at 0x88. But this device implements MSI, VPD, MSI-X capabilities in the reserved spaces. Current code can not handle this.

My question is do we need to add hacks to handle such kinds of devices?
I thought PCI capability offsets could be dynamically determined? If so, or there are other means to easily determine actual capability offsets without requiring explicit device-quirk lists, we should employ those means.

 -- Keir


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