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] Status of ioemu code in unstable?

To: John Byrne <john.l.byrne@xxxxxx>
Subject: Re: [Xen-devel] Status of ioemu code in unstable?
From: Arun Sharma <arun.sharma@xxxxxxxxx>
Date: Mon, 18 Jul 2005 15:26:12 -0700
Cc: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Mon, 18 Jul 2005 22:24:52 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <mailman.1121724192.5752@xxxxxxxxxxxxxxxxxxxx>
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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <42DC2705.6020206@xxxxxx> None None <mailman.1121724192.5752@xxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla Thunderbird 1.0.2 (Windows/20050317)
John Byrne wrote:


I've been trying to find out from the xen-devel archives and Google and I cannot seem to find the information I'm looking for.

I assume the goal of the ioemu is to provide necessary support for non-paravirtualized guess running on VT-x hardware. At a minimum I'd guess you'd need BIOS emulation, display card emulation, and timer/ interrupt emulation.

See foil 10 of:


for a summary of what's working.

Since then, we've added support for BIOS emulation (tools/firmware).
The current device models are based on qemu-0.6.1.

I'd like to know what's there; what works; and what else might be needed. A pointer to the information or a summary would be appreciated. Also, there is one item in the todo list in the wiki that suggests that the ioemu code will all be re-written. Is this for performance reasons?

Yes, switching to dom0 for every I/O request is very expensive. But that was the easiest and cleanest initial implementation.

We've also accelerated the PIT by moving it into the hypervisor and have patches for implementing the local APIC support in xen.


Xen-devel mailing list