From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jack Morgenstein Subject: Re: [PATCH net-next 06/10] net/mlx4_core: Fix struct mlx4_vhcr_cmd to make implicit padding explicit Date: Tue, 27 Jan 2015 16:43:02 +0200 Message-ID: <20150127164302.2b2cc3e0@jpm-OptiPlex-GX620> References: <1422351179-27284-1-git-send-email-amirv@mellanox.com> <1422351179-27284-7-git-send-email-amirv@mellanox.com> <063D6719AE5E284EB5DD2968C1650D6D1CAD3B01@AcuExch.aculab.com> <20150127150027.184ba5e8@jpm-OptiPlex-GX620> <063D6719AE5E284EB5DD2968C1650D6D1CAD3D71@AcuExch.aculab.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: 'Amir Vadai' , "David S. Miller" , "netdev@vger.kernel.org" , "Or Gerlitz" , Yevgeny Petrilin To: David Laight Return-path: Received: from mail-wi0-f172.google.com ([209.85.212.172]:55525 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752207AbbA0OmC (ORCPT ); Tue, 27 Jan 2015 09:42:02 -0500 Received: by mail-wi0-f172.google.com with SMTP id h11so5267043wiw.5 for ; Tue, 27 Jan 2015 06:42:01 -0800 (PST) In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1CAD3D71@AcuExch.aculab.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 27 Jan 2015 13:38:28 +0000 David Laight wrote: > Haven't you broken communication between an old and new > 32bit Guests and 32bit hosts (assuming they exist)? Yes, but I don't see any interest on the net in running 32-bit Hosts with virtualization and SR IOV. I do see that there is interest in running 32-bit Guests over 64-bit Hosts (which configuration KVM supports). Since this change is *required* for supporting 32-bit Guests on 64-bit Hosts, I don't see that we have much choice here. As you say, an old 32-bit Host will not be compatible with a new 32-bit guest, and vice-versa. However, I would assume that almost all Hosts would have 64-bit architectures, because of the performance and memory-space requirements for running SRIOV and virtualization. Therefore, I don't see this as a stopper. -Jack