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] [PATCH] passthru: Fix pci bar remapping for passthru dev

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>, Wei Wang2 <wei.wang2@xxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH] passthru: Fix pci bar remapping for passthru devices
From: "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>
Date: Mon, 20 Jul 2009 23:49:12 +0800
Accept-language: en-US
Acceptlanguage: en-US
Cc:
Delivery-date: Mon, 20 Jul 2009 08:52:59 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C68A424B.FEE0%keir.fraser@xxxxxxxxxxxxx>
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: <E2263E4A5B2284449EEBD0AAB751098402CD29FF14@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> <C68A424B.FEE0%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcoJQvz2mSgR4w1oSxO9+Uupp4ip1AAAbXbgAAEcOowAAYaAkA==
Thread-topic: [Xen-devel] [PATCH] passthru: Fix pci bar remapping for passthru devices
I'm just wondering if this is really needed. See my response to Wei Wang.

Thanks
--jyh

Keir Fraser wrote:
> Are you questioning whether this patch should be applied?
> 
> -- Keir
> 
> On 20/07/2009 15:26, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx> wrote:
> 
>> I assume guest should disable the MMIO in PCI_COMMAND before writing
>> all "1"s to bar register. Otherwise, what will happen on native if
>> guest try to access 0xFFFFFFF0? And if we do update the P2M, will it
>> cause trouble to Xen HV? 
>> 
>> Thanks
>> Yunhong Jiang
>> 
>> xen-devel-bounces@xxxxxxxxxxxxxxxxxxx wrote:
>>> Hi,
>>> When guest code tries to get the block size of mmio, it will write
>>> all "1"s into pci bar register and then qemu will return all "0"s
>>> to the don't care bits in the emulated bar register to indicate the
>>> block size 
>>> to guest code.
>>> In this case, we should not create p2m mapping in
>>> pt_bar_reg_write() and
>>> pt_exp_rom_bar_reg_write(). Attached patch fixes this issue,
>>> additional comment can be found in the patch.
>>> 
>>> Thanks,
>>> Wei
>>> 
>>> Signed-off-by: Wei Wang <wei.wang2@xxxxxxx>
>>> --
>>> AMD GmbH, Germany
>>> Operating System Research Center
>>> 
>>> Legal Information:
>>> Advanced Micro Devices GmbH
>>> Karl-Hammerschmidt-Str. 34
>>> 85609 Dornach b. München
>>> 
>>> Geschäftsführer: Jochen Polster, Thomas M. McCoy, Giuliano Meroni
>>> Sitz: Dornach, Gemeinde Aschheim, Landkreis München
>>> Registergericht München, HRB Nr. 43632
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel