From patchwork Fri Jun 19 18:22:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 11614911 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 35EA914E3 for ; Fri, 19 Jun 2020 18:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18A542158C for ; Fri, 19 Jun 2020 18:25:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YXnHGWJ8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732815AbgFSSYu (ORCPT ); Fri, 19 Jun 2020 14:24:50 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:28000 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2395314AbgFSSXa (ORCPT ); Fri, 19 Jun 2020 14:23:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592591008; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SebELR9P6UdxOZUUJ2/ujOoDNiefkZULx1JR2jGRgfg=; b=YXnHGWJ8nYNJvskxCO3mlI3Csydtk5CTtXxivtp6cRUlSa/FHx0IkjGrOrRgKJXrls6eMs tx3epHVJcsiVrHOtxkLuY6fO67xH7ibeaIFy3gyTANn3Ok5mmUOc0YXzVCVLXeZm/JaUPo oH15IyYJygyOLP9jqSjYvpR9+Z3sCOs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-447-ubwUhsHdPMyzNjEfa-iYaw-1; Fri, 19 Jun 2020 14:23:25 -0400 X-MC-Unique: ubwUhsHdPMyzNjEfa-iYaw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A88F7107ACCA; Fri, 19 Jun 2020 18:23:24 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-113-14.ams2.redhat.com [10.36.113.14]) by smtp.corp.redhat.com (Postfix) with ESMTP id B6CAA7C1E7; Fri, 19 Jun 2020 18:23:22 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: mst@redhat.com Cc: kvm list , Stefano Garzarella , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Stefan Hajnoczi , Jason Wang Subject: [RFC v9 05/11] vhost: format-independent API for used buffers Date: Fri, 19 Jun 2020 20:22:56 +0200 Message-Id: <20200619182302.850-6-eperezma@redhat.com> In-Reply-To: <20200619182302.850-1-eperezma@redhat.com> References: <20200619182302.850-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "Michael S. Tsirkin" Add a new API that doesn't assume used ring, heads, etc. For now, we keep the old APIs around to make it easier to convert drivers. Signed-off-by: Michael S. Tsirkin Signed-off-by: Eugenio Pérez --- drivers/vhost/vhost.c | 73 +++++++++++++++++++++++++++++++++++++------ drivers/vhost/vhost.h | 17 +++++++++- 2 files changed, 79 insertions(+), 11 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index ba8da8785ede..e227e0667790 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2334,13 +2334,12 @@ static void unfetch_descs(struct vhost_virtqueue *vq) * number of output then some number of input descriptors, it's actually two * iovecs, but we pack them into one and note how many of each there were. * - * This function returns the descriptor number found, or vq->num (which is - * never a valid descriptor number) if none was found. A negative code is - * returned on error. */ -int vhost_get_vq_desc(struct vhost_virtqueue *vq, - struct iovec iov[], unsigned int iov_size, - unsigned int *out_num, unsigned int *in_num, - struct vhost_log *log, unsigned int *log_num) + * This function returns a value > 0 if a descriptor was found, or 0 if none were found. + * A negative code is returned on error. */ +int vhost_get_avail_buf(struct vhost_virtqueue *vq, struct vhost_buf *buf, + struct iovec iov[], unsigned int iov_size, + unsigned int *out_num, unsigned int *in_num, + struct vhost_log *log, unsigned int *log_num) { int ret = fetch_descs(vq); int i; @@ -2353,6 +2352,8 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, *out_num = *in_num = 0; if (unlikely(log)) *log_num = 0; + buf->in_len = buf->out_len = 0; + buf->descs = 0; for (i = vq->first_desc; i < vq->ndescs; ++i) { unsigned iov_count = *in_num + *out_num; @@ -2382,6 +2383,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, /* If this is an input descriptor, * increment that count. */ *in_num += ret; + buf->in_len += desc->len; if (unlikely(log && ret)) { log[*log_num].addr = desc->addr; log[*log_num].len = desc->len; @@ -2397,9 +2399,11 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, goto err; } *out_num += ret; + buf->out_len += desc->len; } - ret = desc->id; + buf->id = desc->id; + ++buf->descs; if (!(desc->flags & VRING_DESC_F_NEXT)) break; @@ -2407,12 +2411,41 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, vq->first_desc = i + 1; - return ret; + return 1; err: unfetch_descs(vq); - return ret ? ret : vq->num; + return ret; +} +EXPORT_SYMBOL_GPL(vhost_get_avail_buf); + +/* Reverse the effect of vhost_get_avail_buf. Useful for error handling. */ +void vhost_discard_avail_bufs(struct vhost_virtqueue *vq, + struct vhost_buf *buf, unsigned count) +{ + vhost_discard_vq_desc(vq, count); +} +EXPORT_SYMBOL_GPL(vhost_discard_avail_bufs); + +/* This function returns the descriptor number found, or vq->num (which is + * never a valid descriptor number) if none was found. A negative code is + * returned on error. */ +int vhost_get_vq_desc(struct vhost_virtqueue *vq, + struct iovec iov[], unsigned int iov_size, + unsigned int *out_num, unsigned int *in_num, + struct vhost_log *log, unsigned int *log_num) +{ + struct vhost_buf buf; + int ret = vhost_get_avail_buf(vq, &buf, + iov, iov_size, out_num, in_num, + log, log_num); + + if (likely(ret > 0)) + return buf.id; + if (likely(!ret)) + return vq->num; + return ret; } EXPORT_SYMBOL_GPL(vhost_get_vq_desc); @@ -2506,6 +2539,26 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) } EXPORT_SYMBOL_GPL(vhost_add_used); +int vhost_put_used_buf(struct vhost_virtqueue *vq, struct vhost_buf *buf) +{ + return vhost_add_used(vq, buf->id, buf->in_len); +} +EXPORT_SYMBOL_GPL(vhost_put_used_buf); + +int vhost_put_used_n_bufs(struct vhost_virtqueue *vq, + struct vhost_buf *bufs, unsigned count) +{ + unsigned i; + + for (i = 0; i < count; ++i) { + vq->heads[i].id = cpu_to_vhost32(vq, bufs[i].id); + vq->heads[i].len = cpu_to_vhost32(vq, bufs[i].in_len); + } + + return vhost_add_used_n(vq, vq->heads, count); +} +EXPORT_SYMBOL_GPL(vhost_put_used_n_bufs); + static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) { __u16 old, new; diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index fed36af5c444..28eea0155efb 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -67,6 +67,13 @@ struct vhost_desc { u16 id; }; +struct vhost_buf { + u32 out_len; + u32 in_len; + u16 descs; + u16 id; +}; + /* The virtqueue structure describes a queue attached to a device. */ struct vhost_virtqueue { struct vhost_dev *dev; @@ -195,7 +202,12 @@ int vhost_get_vq_desc(struct vhost_virtqueue *, unsigned int *out_num, unsigned int *in_num, struct vhost_log *log, unsigned int *log_num); void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); - +int vhost_get_avail_buf(struct vhost_virtqueue *, struct vhost_buf *buf, + struct iovec iov[], unsigned int iov_count, + unsigned int *out_num, unsigned int *in_num, + struct vhost_log *log, unsigned int *log_num); +void vhost_discard_avail_bufs(struct vhost_virtqueue *, + struct vhost_buf *, unsigned count); int vhost_vq_init_access(struct vhost_virtqueue *); int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, @@ -204,6 +216,9 @@ void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, unsigned int id, int len); void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, struct vring_used_elem *heads, unsigned count); +int vhost_put_used_buf(struct vhost_virtqueue *, struct vhost_buf *buf); +int vhost_put_used_n_bufs(struct vhost_virtqueue *, + struct vhost_buf *bufs, unsigned count); void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);