From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 3/3] megasas: LSI Megaraid SAS emulation Date: Mon, 04 Jul 2011 09:26:42 +0200 Message-ID: <4E116B32.702@suse.de> References: <1309534555-22178-1-git-send-email-hare@suse.de> <1309534555-22178-2-git-send-email-hare@suse.de> <1309534555-22178-3-git-send-email-hare@suse.de> <1309534555-22178-4-git-send-email-hare@suse.de> <4E0F2215.4040307@suse.de> <4E107E66.3030001@redhat.com> <4E115A21.8010003@suse.de> <4E115EFD.7020607@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Alexander Graf , qemu-devel@nongnu.org, Stefan Haynoczi , "kvm@vger.kernel.org" To: Paolo Bonzini Return-path: Received: from cantor2.suse.de ([195.135.220.15]:33189 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753058Ab1GDH0q (ORCPT ); Mon, 4 Jul 2011 03:26:46 -0400 In-Reply-To: <4E115EFD.7020607@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 07/04/2011 08:34 AM, Paolo Bonzini wrote: > On 07/04/2011 08:13 AM, Hannes Reinecke wrote: >> On 07/03/2011 04:36 PM, Paolo Bonzini wrote: >>> On 07/02/2011 03:50 PM, Hannes Reinecke wrote: >>>> (And no, I will not getting into another dog-fight with Paul B. >>>> here. >>>> Virtio can do without bounce buffers. AHCI can. So I fail to see >>>> why >>>> SCSI has to rely on bounce buffers.) >>> >>> I agree, but I do see why a SCSI device might prefer to rely on >>> bounce buffers for non-I/O commands. This is why in my last RFC >>> series for vmw_pvscsi I let the device choose whether to force a >>> bounce buffer or get an external iovec from the HBA. >>> >> Yes, sure, for non-I/O commands it's perfectly okay. >> Most of which will be emulated anyway. >> It's bounce buffers for I/O which kills performance. >> >> But I seem to have missed your last RFC (I'm not reading >> qemu-devel on a >> regular basis ...). >> Care to send me a pointer to it? > > Sure, > http://lists.gnu.org/archive/html/qemu-devel/2011-06/msg00668.html > Cool. Exactly what I need. =46WIW, feel free to add my 'Acked-by' to it. Any chance of getting them included? Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg)