From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [RFC V3 PATCH 0/8] Packed ring for vhost Date: Mon, 23 Apr 2018 15:31:20 -0400 Message-ID: <20180423193120.GD30033@char.us.oracle.com> References: <1524461700-5469-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1524461700-5469-1-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Jason Wang Cc: kvm@vger.kernel.org, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, wexu@redhat.com List-Id: virtualization@lists.linuxfoundation.org On Mon, Apr 23, 2018 at 01:34:52PM +0800, Jason Wang wrote: > Hi all: > > This RFC implement packed ring layout. The code were tested with > Tiwei's RFC V2 a thttps://lkml.org/lkml/2018/4/1/48. Some fixups and > tweaks were needed on top of Tiwei's code to make it run. TCP stream > and pktgen does not show obvious difference compared with split ring. I have to ask then - what is the benefit of this? > > Changes from V2: > - do not use & in checking desc_event_flags > - off should be most significant bit > - remove the workaround of mergeable buffer for dpdk prototype > - id should be in the last descriptor in the chain > - keep _F_WRITE for write descriptor when adding used > - device flags updating should use ADDR_USED type > - return error on unexpected unavail descriptor in a chain > - return false in vhost_ve_avail_empty is descriptor is available > - track last seen avail_wrap_counter > - correctly examine available descriptor in get_indirect_packed() > - vhost_idx_diff should return u16 instead of bool > > Changes from V1: > > - Refactor vhost used elem code to avoid open coding on used elem > - Event suppression support (compile test only). > - Indirect descriptor support (compile test only). > - Zerocopy support. > - vIOMMU support. > - SCSI/VSOCK support (compile test only). > - Fix several bugs > > For simplicity, I don't implement batching or other optimizations. > > Please review. > > Jason Wang (8): > vhost: move get_rx_bufs to vhost.c > vhost: hide used ring layout from device > vhost: do not use vring_used_elem > vhost_net: do not explicitly manipulate vhost_used_elem > vhost: vhost_put_user() can accept metadata type > virtio: introduce packed ring defines > vhost: packed ring support > vhost: event suppression for packed ring > > drivers/vhost/net.c | 136 ++---- > drivers/vhost/scsi.c | 62 +-- > drivers/vhost/vhost.c | 824 ++++++++++++++++++++++++++++++++++--- > drivers/vhost/vhost.h | 47 ++- > drivers/vhost/vsock.c | 42 +- > include/uapi/linux/virtio_config.h | 9 + > include/uapi/linux/virtio_ring.h | 32 ++ > 7 files changed, 926 insertions(+), 226 deletions(-) > > -- > 2.7.4 >