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

[Xen-devel] question about dom0 accessing physical device

To: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] question about dom0 accessing physical device
From: 刘志建 <aleck_liu@xxxxxxx>
Date: Mon, 10 Nov 2008 11:02:54 +0800 (CST)
Delivery-date: Sun, 09 Nov 2008 19:03:27 -0800
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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Hello all,
It seems to me that when dom0 uses in/out instructions, GP fault will occur, And Xen will check the io accessing permissions, and then performs the operation for dom0. 
My question is : why not use the  io-bitmap which is in TSS, to allow dom0 to access the physical devices' IO ports? 
As to the mmio,  the MMU virtualization can also allow dom0 to map device memory areas to its virtual memory space, so that there will be no VMM intervence either.
why  the above approaches are not adopted by Xen? Would anyone tell me the reason?
Thanks a lot.
 
 --    The Following is added by the ISP.
           Please ignore them!

以下信息由邮件服务器提供商自动添加,与本邮件内容无关!


[广告] 金秋最关注楼盘-房不胜房
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-devel] question about dom0 accessing physical device, 刘志建 <=