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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 EE773C3279B for ; Wed, 4 Jul 2018 08:14:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B173620837 for ; Wed, 4 Jul 2018 08:14:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B173620837 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934048AbeGDION (ORCPT ); Wed, 4 Jul 2018 04:14:13 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:54838 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932290AbeGDIOJ (ORCPT ); Wed, 4 Jul 2018 04:14:09 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EFF0040201C7; Wed, 4 Jul 2018 08:14:08 +0000 (UTC) Received: from wei-ubt (dhcp-14-122.nay.redhat.com [10.66.14.122]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 42FB5111C4A2; Wed, 4 Jul 2018 08:13:57 +0000 (UTC) Date: Wed, 4 Jul 2018 16:13:56 +0800 From: Wei Xu To: Jason Wang Cc: mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tiwei.bie@intel.com, maxime.coquelin@redhat.com, jfreimann@redhat.com Subject: Re: [PATCH net-next 8/8] vhost: event suppression for packed ring Message-ID: <20180704081356.GB9287@wei-ubt> References: <1530596284-4101-1-git-send-email-jasowang@redhat.com> <1530596284-4101-9-git-send-email-jasowang@redhat.com> <20180704041352.GA9287@wei-ubt> <493c3a3e-e088-d6fb-1da4-cda8bfb34400@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <493c3a3e-e088-d6fb-1da4-cda8bfb34400@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 04 Jul 2018 08:14:09 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 04 Jul 2018 08:14:09 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'wexu@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 04, 2018 at 01:23:18PM +0800, Jason Wang wrote: > > > On 2018年07月04日 12:13, Wei Xu wrote: > >On Tue, Jul 03, 2018 at 01:38:04PM +0800, Jason Wang wrote: > >>This patch introduces support for event suppression. This is done by > >>have a two areas: device area and driver area. One side could then try > >>to disable or enable (delayed) notification from other side by using a > >>boolean hint or event index interface in the areas. > >> > >>For more information, please refer Virtio spec. > >> > >>Signed-off-by: Jason Wang > >>--- > >> drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++++++++++++---- > >> drivers/vhost/vhost.h | 10 ++- > >> 2 files changed, 185 insertions(+), 16 deletions(-) > >> > >>diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > >>index 0f3f07c..cccbc82 100644 > >>--- a/drivers/vhost/vhost.c > >>+++ b/drivers/vhost/vhost.c > >>@@ -1115,10 +1115,15 @@ static int vq_access_ok_packed(struct vhost_virtqueue *vq, unsigned int num, > >> struct vring_used __user *used) > >> { > >> struct vring_desc_packed *packed = (struct vring_desc_packed *)desc; > >>+ struct vring_packed_desc_event *driver_event = > >>+ (struct vring_packed_desc_event *)avail; > >>+ struct vring_packed_desc_event *device_event = > >>+ (struct vring_packed_desc_event *)used; > >>- /* TODO: check device area and driver area */ > >> return access_ok(VERIFY_READ, packed, num * sizeof(*packed)) && > >>- access_ok(VERIFY_WRITE, packed, num * sizeof(*packed)); > >>+ access_ok(VERIFY_WRITE, packed, num * sizeof(*packed)) && > >R/W parameter doesn't make sense to most architectures and the comment in x86 > >says WRITE is a superset of READ, is it possible to converge them here? > > > >/** > > * access_ok: - Checks if a user space pointer is valid > > * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that > > * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe > > * to write to a block, it is always safe to read from it. > > * @addr: User space pointer to start of block to check > > * @size: Size of block to check > > * > > * Context: User context only. This function may sleep if pagefaults are > > * enabled. > > * > > * Checks if a pointer to a block of memory in user space is valid. > > * > > * Returns true (nonzero) if the memory block may be valid, false (zero) > > * if it is definitely invalid. > > * > > * Note that, depending on architecture, this function probably just > > * checks that the pointer is in the user space range - after calling > > * this function, memory access functions may still return -EFAULT. > > */ > >#define access_ok(type, addr, size) > >...... > > > >Thanks, > >Wei > > > > Well, this is a question that beyond the scope of this patch. > > My understanding is we should keep it unless type was meaningless on all > archs. No problem, go ahead. Wei > > Thanks >