From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9DDDC31E49 for ; Wed, 19 Jun 2019 08:17:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86C7C206E0 for ; Wed, 19 Jun 2019 08:17:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731135AbfFSIRN (ORCPT ); Wed, 19 Jun 2019 04:17:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33740 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730783AbfFSIRM (ORCPT ); Wed, 19 Jun 2019 04:17:12 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CE8613082263; Wed, 19 Jun 2019 08:17:12 +0000 (UTC) Received: from gondolin (dhcp-192-192.str.redhat.com [10.33.192.192]) by smtp.corp.redhat.com (Postfix) with ESMTP id B8F4F5C220; Wed, 19 Jun 2019 08:17:11 +0000 (UTC) Date: Wed, 19 Jun 2019 10:17:09 +0200 From: Cornelia Huck To: Eric Farman Cc: Farhan Ali , Halil Pasic , linux-s390@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [RFC PATCH v1 2/5] vfio-ccw: Skip second copy of guest cp to host Message-ID: <20190619101709.2985e80e.cohuck@redhat.com> In-Reply-To: <20190618202352.39702-3-farman@linux.ibm.com> References: <20190618202352.39702-1-farman@linux.ibm.com> <20190618202352.39702-3-farman@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 19 Jun 2019 08:17:12 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 18 Jun 2019 22:23:49 +0200 Eric Farman wrote: > We already pinned/copied/unpinned 2K (256 CCWs) of guest memory > to the host space anchored off vfio_ccw_private. There's no need > to do that again once we have the length calculated, when we could > just copy the section we need to the "permanent" space for the I/O. > > Signed-off-by: Eric Farman > --- > drivers/s390/cio/vfio_ccw_cp.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) Reviewed-by: Cornelia Huck