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,URIBL_BLOCKED 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 33342C46469 for ; Wed, 12 Sep 2018 12:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAA7920880 for ; Wed, 12 Sep 2018 12:53:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CAA7920880 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 S1727010AbeILR5r (ORCPT ); Wed, 12 Sep 2018 13:57:47 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45304 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726359AbeILR5r (ORCPT ); Wed, 12 Sep 2018 13:57:47 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6894B87A7D; Wed, 12 Sep 2018 12:53:23 +0000 (UTC) Received: from redhat.com (ovpn-121-244.rdu2.redhat.com [10.10.121.244]) by smtp.corp.redhat.com (Postfix) with SMTP id 96DB62027EA4; Wed, 12 Sep 2018 12:53:20 +0000 (UTC) Date: Wed, 12 Sep 2018 08:53:20 -0400 From: "Michael S. Tsirkin" To: Tiwei Bie Cc: jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, virtio-dev@lists.oasis-open.org, wexu@redhat.com, jfreimann@redhat.com Subject: Re: [PATCH net-next v2 1/5] virtio: add packed ring definitions Message-ID: <20180912084549-mutt-send-email-mst@kernel.org> References: <20180711022711.7090-1-tiwei.bie@intel.com> <20180711022711.7090-2-tiwei.bie@intel.com> <20180907094922-mutt-send-email-mst@kernel.org> <20180910021322.GA10912@debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180910021322.GA10912@debian> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 12 Sep 2018 12:53:23 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 12 Sep 2018 12:53:23 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 10, 2018 at 10:13:22AM +0800, Tiwei Bie wrote: > On Fri, Sep 07, 2018 at 09:51:23AM -0400, Michael S. Tsirkin wrote: > > On Wed, Jul 11, 2018 at 10:27:07AM +0800, Tiwei Bie wrote: > > > Signed-off-by: Tiwei Bie > > > --- > > > include/uapi/linux/virtio_config.h | 3 +++ > > > include/uapi/linux/virtio_ring.h | 43 ++++++++++++++++++++++++++++++ > > > 2 files changed, 46 insertions(+) > > > > > > diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h > > > index 449132c76b1c..1196e1c1d4f6 100644 > > > --- a/include/uapi/linux/virtio_config.h > > > +++ b/include/uapi/linux/virtio_config.h > > > @@ -75,6 +75,9 @@ > > > */ > > > #define VIRTIO_F_IOMMU_PLATFORM 33 > > > > > > +/* This feature indicates support for the packed virtqueue layout. */ > > > +#define VIRTIO_F_RING_PACKED 34 > > > + > > > /* > > > * 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 6d5d5faa989b..0254a2ba29cf 100644 > > > --- a/include/uapi/linux/virtio_ring.h > > > +++ b/include/uapi/linux/virtio_ring.h > > > @@ -44,6 +44,10 @@ > > > /* This means the buffer contains a list of buffer descriptors. */ > > > #define VRING_DESC_F_INDIRECT 4 > > > > > > +/* Mark a descriptor as available or used. */ > > > +#define VRING_DESC_F_AVAIL (1ul << 7) > > > +#define VRING_DESC_F_USED (1ul << 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. */ > > > @@ -53,6 +57,17 @@ > > > * optimization. */ > > > #define VRING_AVAIL_F_NO_INTERRUPT 1 > > > > > > +/* Enable events. */ > > > +#define VRING_EVENT_F_ENABLE 0x0 > > > +/* Disable events. */ > > > +#define VRING_EVENT_F_DISABLE 0x1 > > > +/* > > > + * Enable events for a specific descriptor > > > + * (as specified by Descriptor Ring Change Event Offset/Wrap Counter). > > > + * Only valid if VIRTIO_RING_F_EVENT_IDX has been negotiated. > > > + */ > > > +#define VRING_EVENT_F_DESC 0x2 > > > + > > > /* We support indirect buffer descriptors */ > > > #define VIRTIO_RING_F_INDIRECT_DESC 28 > > > > > > > These are for the packed ring, right? Pls prefix accordingly. > > How about something like this: > > #define VRING_PACKED_DESC_F_AVAIL (1u << 7) > #define VRING_PACKED_DESC_F_USED (1u << 15) _F_ should be a bit number, not a shifted value. Yes I know current virtio_ring.h is inconsistent in that respect. changes welcome though we need to maintain the old names for the sake of old apps. > > #define VRING_PACKED_EVENT_F_ENABLE 0x0 > #define VRING_PACKED_EVENT_F_DISABLE 0x1 > #define VRING_PACKED_EVENT_F_DESC 0x2 These are values, I think they should not have _F_. Yes I know current virtio_ring.h is inconsistent in that respect. > > > Also, you likely need macros for the wrap counters. > > How about something like this: > > #define VRING_PACKED_EVENT_WRAP_COUNTER_SHIFT 15 Given it's a single bit, maybe even VRING_PACKED_EVENT_F_WRAP_CTR > #define VRING_PACKED_EVENT_WRAP_COUNTER_MASK \ > (1u << VRING_PACKED_WRAP_COUNTER_SHIFT) > #define VRING_PACKED_EVENT_OFFSET_MASK \ > ((1u << VRING_PACKED_WRAP_COUNTER_SHIFT) - 1) I'm not sure the mask is justified. > > > > > @@ -171,4 +186,32 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old) > > > return (__u16)(new_idx - event_idx - 1) < (__u16)(new_idx - old); > > > } > > > > > > +struct vring_packed_desc_event { > > > + /* Descriptor Ring Change Event Offset/Wrap Counter. */ > > > + __virtio16 off_wrap; > > > + /* Descriptor Ring Change Event Flags. */ > > > + __virtio16 flags; > > > +}; > > > + > > > +struct vring_packed_desc { > > > + /* Buffer Address. */ > > > + __virtio64 addr; > > > + /* Buffer Length. */ > > > + __virtio32 len; > > > + /* Buffer ID. */ > > > + __virtio16 id; > > > + /* The flags depending on descriptor type. */ > > > + __virtio16 flags; > > > +}; > > > > Don't use __virtioXX types, just __leXX ones. > > Got it, will do that. > > > > > > + > > > +struct vring_packed { > > > + unsigned int num; > > > + > > > + struct vring_packed_desc *desc; > > > + > > > + struct vring_packed_desc_event *driver; > > > + > > > + struct vring_packed_desc_event *device; > > > +}; > > > + > > > #endif /* _UAPI_LINUX_VIRTIO_RING_H */ > > > -- > > > 2.18.0