From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC PATCH 0/3] generic hypercall support Date: Thu, 07 May 2009 21:05:37 +0300 Message-ID: <4A0322F1.2000905@redhat.com> References: <20090505132005.19891.78436.stgit@dev.haskins.net> <4A0040C0.1080102@redhat.com> <4A0041BA.6060106@novell.com> <4A004676.4050604@redhat.com> <4A0049CD.3080003@gmail.com> <20090505231718.GT3036@sequoia.sous-sol.org> <4A010927.6020207@novell.com> <20090506072212.GV3036@sequoia.sous-sol.org> <4A018DF2.6010301@novell.com> <20090506160712.GW3036@sequoia.sous-sol.org> <4A031471.7000406@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Chris Wright , Gregory Haskins , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Anthony Liguori To: Gregory Haskins Return-path: Received: from mx2.redhat.com ([66.187.237.31]:50617 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752278AbZEGSGd (ORCPT ); Thu, 7 May 2009 14:06:33 -0400 In-Reply-To: <4A031471.7000406@novell.com> Sender: kvm-owner@vger.kernel.org List-ID: Gregory Haskins wrote: > I completed the resurrection of the test and wrote up a little wiki on > the subject, which you can find here: > > http://developer.novell.com/wiki/index.php/WhyHypercalls > > Hopefully this answers Chris' "show me the numbers" and Anthony's "Why > reinvent the wheel?" questions. > > I will include this information when I publish the updated v2 series > with the s/hypercall/dynhc changes. > > Let me know if you have any questions. > Well, 420 ns is not to be sneezed at. What do you think of my mmio hypercall? That will speed up all mmio to be as fast as a hypercall, and then we can use ordinary mmio/pio writes to trigger things. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.