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 3C7E7C3279B for ; Wed, 4 Jul 2018 04:48:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E66422469C for ; Wed, 4 Jul 2018 04:48:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E66422469C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.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 S932625AbeGDEs1 (ORCPT ); Wed, 4 Jul 2018 00:48:27 -0400 Received: from mga06.intel.com ([134.134.136.31]:37948 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbeGDEsZ (ORCPT ); Wed, 4 Jul 2018 00:48:25 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jul 2018 21:48:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,306,1526367600"; d="scan'208";a="54969094" Received: from debian.sh.intel.com (HELO debian) ([10.67.104.228]) by orsmga006.jf.intel.com with ESMTP; 03 Jul 2018 21:48:22 -0700 Date: Wed, 4 Jul 2018 12:48:23 +0800 From: Tiwei Bie 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, wexu@redhat.com, maxime.coquelin@redhat.com, jfreimann@redhat.com Subject: Re: [PATCH net-next 6/8] virtio: introduce packed ring defines Message-ID: <20180704044823.GA22808@debian> References: <1530596284-4101-1-git-send-email-jasowang@redhat.com> <1530596284-4101-7-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1530596284-4101-7-git-send-email-jasowang@redhat.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > + > /* > * 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. > +#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). 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; > + /* 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 > +/* 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 >