From patchwork Fri Dec 7 08:48:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiwei Bie X-Patchwork-Id: 1009227 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43B5mW2gv4z9s3q for ; Fri, 7 Dec 2018 19:51:23 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725996AbeLGIvD (ORCPT ); Fri, 7 Dec 2018 03:51:03 -0500 Received: from mga18.intel.com ([134.134.136.126]:1705 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725978AbeLGIvC (ORCPT ); Fri, 7 Dec 2018 03:51:02 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Dec 2018 00:51:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,324,1539673200"; d="scan'208";a="96888331" Received: from btwcube1.sh.intel.com ([10.67.104.173]) by orsmga007.jf.intel.com with ESMTP; 07 Dec 2018 00:50:59 -0800 From: Tiwei Bie To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, virtio-dev@lists.oasis-open.org Cc: wexu@redhat.com, jfreimann@redhat.com, maxime.coquelin@redhat.com, tiwei.bie@intel.com Subject: [RFC 1/3] virtio_ring: define flags as shifts consistently Date: Fri, 7 Dec 2018 16:48:40 +0800 Message-Id: <20181207084842.13133-2-tiwei.bie@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181207084842.13133-1-tiwei.bie@intel.com> References: <20181207084842.13133-1-tiwei.bie@intel.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Introduce _SPLIT_ and/or _PACKED_ variants for VRING_DESC_F_*, VRING_AVAIL_F_NO_INTERRUPT and VRING_USED_F_NO_NOTIFY. These variants are defined as shifts instead of shifted values for consistency with other _F_ flags. Suggested-by: Michael S. Tsirkin Signed-off-by: Tiwei Bie --- include/uapi/linux/virtio_ring.h | 57 ++++++++++++++++++++++---------- 1 file changed, 40 insertions(+), 17 deletions(-) diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h index 2414f8af26b3..9b0c0d92ab62 100644 --- a/include/uapi/linux/virtio_ring.h +++ b/include/uapi/linux/virtio_ring.h @@ -37,29 +37,52 @@ #include #include -/* This marks a buffer as continuing via the next field. */ +/* + * Notice: unlike other _F_ flags, below flags are defined as shifted + * values instead of shifts for compatibility. + */ +/* Same as VRING_SPLIT_DESC_F_NEXT. */ #define VRING_DESC_F_NEXT 1 -/* This marks a buffer as write-only (otherwise read-only). */ +/* Same as VRING_SPLIT_DESC_F_WRITE. */ #define VRING_DESC_F_WRITE 2 -/* This means the buffer contains a list of buffer descriptors. */ +/* Same as VRING_SPLIT_DESC_F_INDIRECT. */ #define VRING_DESC_F_INDIRECT 4 - -/* - * Mark a descriptor as available or used in packed ring. - * Notice: they are defined as shifts instead of shifted values. - */ -#define VRING_PACKED_DESC_F_AVAIL 7 -#define VRING_PACKED_DESC_F_USED 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 - * will still kick if it's out of buffers. */ +/* Same as VRING_SPLIT_USED_F_NO_NOTIFY. */ #define VRING_USED_F_NO_NOTIFY 1 -/* The Guest uses this in avail->flags to advise the Host: don't interrupt me - * when you consume a buffer. It's unreliable, so it's simply an - * optimization. */ +/* Same as VRING_SPLIT_AVAIL_F_NO_INTERRUPT. */ #define VRING_AVAIL_F_NO_INTERRUPT 1 +/* Mark a buffer as continuing via the next field in split ring. */ +#define VRING_SPLIT_DESC_F_NEXT 0 +/* Mark a buffer as write-only (otherwise read-only) in split ring. */ +#define VRING_SPLIT_DESC_F_WRITE 1 +/* Mean the buffer contains a list of buffer descriptors in split ring. */ +#define VRING_SPLIT_DESC_F_INDIRECT 2 + +/* + * The Host uses this in used->flags in split ring to advise the Guest: + * don't kick me when you add a buffer. It's unreliable, so it's simply + * an optimization. Guest will still kick if it's out of buffers. + */ +#define VRING_SPLIT_USED_F_NO_NOTIFY 0 +/* + * The Guest uses this in avail->flags in split ring to advise the Host: + * don't interrupt me when you consume a buffer. It's unreliable, so it's + * simply an optimization. + */ +#define VRING_SPLIT_AVAIL_F_NO_INTERRUPT 0 + +/* Mark a buffer as continuing via the next field in packed ring. */ +#define VRING_PACKED_DESC_F_NEXT 0 +/* Mark a buffer as write-only (otherwise read-only) in packed ring. */ +#define VRING_PACKED_DESC_F_WRITE 1 +/* Mean the buffer contains a list of buffer descriptors in packed ring. */ +#define VRING_PACKED_DESC_F_INDIRECT 2 + +/* Mark a descriptor as available or used in packed ring. */ +#define VRING_PACKED_DESC_F_AVAIL 7 +#define VRING_PACKED_DESC_F_USED 15 + /* Enable events in packed ring. */ #define VRING_PACKED_EVENT_FLAG_ENABLE 0x0 /* Disable events in packed ring. */