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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 D2584C3279B for ; Wed, 4 Jul 2018 05:26:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9491A24740 for ; Wed, 4 Jul 2018 05:26:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9491A24740 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 S933026AbeGDF0j (ORCPT ); Wed, 4 Jul 2018 01:26:39 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50412 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752975AbeGDF0h (ORCPT ); Wed, 4 Jul 2018 01:26:37 -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 3BB79401DEA8; Wed, 4 Jul 2018 05:26:37 +0000 (UTC) Received: from [10.72.12.45] (ovpn-12-45.pek2.redhat.com [10.72.12.45]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4336510FD2A1; Wed, 4 Jul 2018 05:26:26 +0000 (UTC) Subject: Re: [PATCH net-next 6/8] virtio: introduce packed ring defines To: Tiwei Bie Cc: mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, wexu@redhat.com, maxime.coquelin@redhat.com, jfreimann@redhat.com References: <1530596284-4101-1-git-send-email-jasowang@redhat.com> <1530596284-4101-7-git-send-email-jasowang@redhat.com> <20180704044823.GA22808@debian> From: Jason Wang Message-ID: <81c82dfe-54f9-671c-695a-68c309fa1b73@redhat.com> Date: Wed, 4 Jul 2018 13:26:24 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180704044823.GA22808@debian> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US 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 05:26:37 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 04 Jul 2018 05:26:37 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jasowang@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018年07月04日 12:48, Tiwei Bie wrote: > On Tue, Jul 03, 2018 at 01:38:02PM +0800, Jason Wang wrote: >> Signed-off-by: Jason Wang >> --- >> include/uapi/linux/virtio_config.h | 2 ++ >> include/uapi/linux/virtio_ring.h | 32 ++++++++++++++++++++++++++++++++ >> 2 files changed, 34 insertions(+) >> >> diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h >> index 449132c..947f6a3 100644 >> --- a/include/uapi/linux/virtio_config.h >> +++ b/include/uapi/linux/virtio_config.h >> @@ -75,6 +75,8 @@ >> */ >> #define VIRTIO_F_IOMMU_PLATFORM 33 >> >> +#define VIRTIO_F_RING_PACKED 34 > It's better to add some comments for this macro. Ok. > >> + >> /* >> * Does the device support Single Root I/O Virtualization? >> */ >> diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h >> index 6d5d5fa..71c7a46 100644 >> --- a/include/uapi/linux/virtio_ring.h >> +++ b/include/uapi/linux/virtio_ring.h >> @@ -43,6 +43,8 @@ >> #define VRING_DESC_F_WRITE 2 >> /* This means the buffer contains a list of buffer descriptors. */ >> #define VRING_DESC_F_INDIRECT 4 >> +#define VRING_DESC_F_AVAIL 7 > It's better to use tab between VRING_DESC_F_AVAIL and 7. Let me fix. > >> +#define VRING_DESC_F_USED 15 > Maybe it's better to define VRING_DESC_F_AVAIL and > VRING_DESC_F_USED as (1 << 7) and (1 << 15) or something > similar to make them consistent with VRING_DESC_F_NEXT > (1 << 0), VRING_DESC_F_WRITE (1 << 1) and > VRING_DESC_F_INDIRECT (1 << 2). Ok. > > I plan to define below macros in virtio_ring.c: > > #define _VRING_DESC_F_AVAIL(b) ((__u16)(b) << 7) > #define _VRING_DESC_F_USED(b) ((__u16)(b) << 15) > >> >> /* The Host uses this in used->flags to advise the Guest: don't kick me when >> * you add a buffer. It's unreliable, so it's simply an optimization. Guest >> @@ -62,6 +64,36 @@ >> * at the end of the used ring. Guest should ignore the used->flags field. */ >> #define VIRTIO_RING_F_EVENT_IDX 29 >> >> +struct vring_desc_packed { > We may have other related types named as: > > struct vring_packed; > struct vring_packed_desc_event; > > So maybe it's better to name this type as: > > struct vring_packed_desc; Yes. > >> + /* Buffer Address. */ >> + __virtio64 addr; >> + /* Buffer Length. */ >> + __virtio32 len; >> + /* Buffer ID. */ >> + __virtio16 id; >> + /* The flags depending on descriptor type. */ >> + __virtio16 flags; >> +}; >> + >> +/* Enable events */ >> +#define RING_EVENT_FLAGS_ENABLE 0x0 >> +/* Disable events */ >> +#define RING_EVENT_FLAGS_DISABLE 0x1 >> +/* >> + * Enable events for a specific descriptor >> + * (as specified by Descriptor Ring Change Event Offset/Wrap Counter). >> + * Only valid if VIRTIO_F_RING_EVENT_IDX has been negotiated. >> + */ >> +#define RING_EVENT_FLAGS_DESC 0x2 > For above three macros, maybe it's better to name > them as: > > VRING_EVENT_FLAGS_ENABLE > VRING_EVENT_FLAGS_DISABLE > VRING_EVENT_FLAGS_DESC > > or > > VRING_EVENT_F_ENABLE > VRING_EVENT_F_DISABLE > VRING_EVENT_F_DESC > > VRING_EVENT_F_* will be more consistent with > VIRTIO_F_*, VRING_DESC_F_*, etc True. Let me fix above in next version. Thanks >> +/* The value 0x3 is reserved */ >> + >> +struct vring_packed_desc_event { >> + /* Descriptor Ring Change Event Offset and Wrap Counter */ >> + __virtio16 off_wrap; >> + /* Descriptor Ring Change Event Flags */ >> + __virtio16 flags; >> +}; >> + >> /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ >> struct vring_desc { >> /* Address (guest-physical). */ >> -- >> 2.7.4 >>