From patchwork Wed Jun 10 11:36:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 11597559 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 D8896739 for ; Wed, 10 Jun 2020 11:37:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB7112078C for ; Wed, 10 Jun 2020 11:37:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="bVFmEACu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728675AbgFJLg0 (ORCPT ); Wed, 10 Jun 2020 07:36:26 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:23353 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728628AbgFJLgT (ORCPT ); Wed, 10 Jun 2020 07:36:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591788976; 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: in-reply-to:in-reply-to:references:references; bh=eiJhq6XkiotudOh+ZUxsjtY7w6RhDlW9rQ8WDNYh8GQ=; b=bVFmEACuVOQxdotsJMN90zuG3AsNEZ3qb7hhAYac7EB2GWc2447aE9YVxQ5kg6Y/ZF9OON dfrZn26upCXzu2/0O9TGvRyomeJ0+4mBW5SrFPtEtjyrZrN9uCHala0mx6F2k2Ir6Rsx3U nJ8S5jNsIaVhIDv+YAHfg8TYD0cxShc= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-118-IOvz8mdxM3W7Kp_8o-ATyQ-1; Wed, 10 Jun 2020 07:36:15 -0400 X-MC-Unique: IOvz8mdxM3W7Kp_8o-ATyQ-1 Received: by mail-wm1-f71.google.com with SMTP id x6so399736wmj.9 for ; Wed, 10 Jun 2020 04:36:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=eiJhq6XkiotudOh+ZUxsjtY7w6RhDlW9rQ8WDNYh8GQ=; b=ipGG6WAOD/CPghX6SBUOhU2PE9TW+L4uvH4PxG+u6IH4dq5lTOOR3wgUFl+yO9moG3 RZPTCV26tYqk1iRjNxbjcC+6YY+fW1G0xfZS1c4zB0v9Uk6engAtdzqXV1RUfr5K4Jov m9CMWqUaXbhlWc97XtMQ0vVzW4pOUgT2iIkSKxA49VRkFNlJvnDHf8h1csFXJPeN1xG7 sEiTG4qVqGuJGOiOovPeuXRVHofvJfjdY7V3sdU0PZoVt6ohZIxXhxWBqTUhTWGTj8gf RDBOVRpKgC8Epz6Y+808DLTigQY41R0Xo2DbALzl23Ydrlyr93uapP/dqrFD50bqeVxK 096Q== X-Gm-Message-State: AOAM531SC9JBDhRvRR9BGXE4ZbJ4FQNWFGUOVbA3eXdL5yoCpWHayrj7 Ri/pifAAxt4kgkumkv1KuxG2tCNhH8mJF3O/0OLxthwN4SacEs78FD4HE+DiPjsIPPWhKIhGtTi sssrQeByUVjq2 X-Received: by 2002:a05:6000:90:: with SMTP id m16mr3301318wrx.191.1591788973797; Wed, 10 Jun 2020 04:36:13 -0700 (PDT) X-Google-Smtp-Source: ABdhPJw3FpICO0VZ3PPjidPQ1UtjzBsY39xeOmErAI9iBPh+xj1HDRPcA/UbjrzbUg24Tj112L9uRg== X-Received: by 2002:a05:6000:90:: with SMTP id m16mr3301287wrx.191.1591788973510; Wed, 10 Jun 2020 04:36:13 -0700 (PDT) Received: from redhat.com ([212.92.121.57]) by smtp.gmail.com with ESMTPSA id b132sm6626772wmh.3.2020.06.10.04.36.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jun 2020 04:36:13 -0700 (PDT) Date: Wed, 10 Jun 2020 07:36:10 -0400 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, Jason Wang , eperezma@redhat.com Subject: [PATCH RFC v7 06/14] vhost: format-independent API for used buffers Message-ID: <20200610113515.1497099-7-mst@redhat.com> References: <20200610113515.1497099-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200610113515.1497099-1-mst@redhat.com> X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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 --- drivers/vhost/vhost.c | 52 ++++++++++++++++++++++++++++++++++--------- drivers/vhost/vhost.h | 17 +++++++++++++- 2 files changed, 58 insertions(+), 11 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 506208b63126..e5763d81bf0f 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2339,13 +2339,12 @@ 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; @@ -2358,6 +2357,8 @@ 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; @@ -2387,6 +2388,7 @@ 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; @@ -2402,9 +2404,11 @@ 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; @@ -2412,14 +2416,22 @@ 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; } -EXPORT_SYMBOL_GPL(vhost_get_vq_desc); +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); /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) @@ -2511,6 +2523,26 @@ 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 *);