From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tristan Gingold Subject: Re: Re: Improving hvm IO performance by using self IO emulator (YA io-emu?) Date: Sat, 24 Feb 2007 07:19:36 +0100 Message-ID: <20070224061936.GD2508@saphi> References: <20070222052309.GA2764@saphi> <1172177938.45de041286155@imp.free.fr> <45DE09B7.3030003@us.ibm.com> <200702222141.20969.mark.williamson@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200702222141.20969.mark.williamson@cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Mark Williamson Cc: tgingold@free.fr, Anthony Liguori , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Thu, Feb 22, 2007 at 09:41:20PM +0000, Mark Williamson wrote: > While I'm thinking about it, I wonder how returning to the guest from the > emulator would work... > > We'd want to hypercall to transfer back to it... do we need specific Xen > support for this or could (for instance) Gerd's work on domU kexec be > leveraged here? > > Perhaps it would be worth evaluating some kind of "send these events and then > switch back to guest code" hypercall so that the emulator doesn't have to > bounce in and out of Xen so much. Remains to be seen whether this makes much > diffecence to overall performance but it seems somehow civilised ;-) For sure, there are a lot of possible minor optimization points... Tristan.