From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754458Ab2LLEMR (ORCPT ); Tue, 11 Dec 2012 23:12:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59098 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754117Ab2LLEMP (ORCPT ); Tue, 11 Dec 2012 23:12:15 -0500 Date: Wed, 12 Dec 2012 00:11:32 -0200 From: Marcelo Tosatti To: Alex Williamson Cc: gleb@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH v2 00/10] kvm: memory slot cleanups, fix, and increase Message-ID: <20121212021132.GD2898@amt.cnet> References: <20121210171417.10461.20079.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121210171417.10461.20079.stgit@bling.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 10, 2012 at 10:32:39AM -0700, Alex Williamson wrote: > v2: Update 02/10 to not check userspace_addr when slot is removed. > Yoshikawa-san withdrew objection to increase slot_bitmap prior > to his series to remove slot_bitmap. > > This series does away with any kind of complicated resizing of the > slot array and simply does a one time increase. I do compact struct > kvm_memory_slot a bit to take better advantage of the space we are > using. This reduces each slot from 64 bytes (x86_64) to 56 bytes. > By enforcing the API around valid operations for an unused slot and > fields that can be modified runtime, I found and was able to fix a > bug in iommu mapping for slots. The renames enabled me to find the > previously posted bug fix for catching slot overlaps. > > As mentioned in the series, the primary motivation for increasing > memory slots is assigned devices. With this, I've been able to > assign 30 devices to a single VM and could have gone further, but > ran out of SRIOV VFs. Typical devices use anywhere from 2-4 slots > and max out at 8 slots. 125 user slots (3 private slots) allows > us to support between 28 and 56 typical devices per VM. > > Tested on x86_64, compiled on ia64, powerpc, and s390. > > Thanks, > Alex Reviewed-by: Marcelo Tosatti