From patchwork Tue Jun 5 19:07:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Xu X-Patchwork-Id: 925610 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 410hN91l76z9s15 for ; Wed, 6 Jun 2018 05:15:37 +1000 (AEST) Received: from localhost ([::1]:48689 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQHQc-0008Kd-N4 for incoming@patchwork.ozlabs.org; Tue, 05 Jun 2018 15:15:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42577) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQHJg-00024g-Kk for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQHJf-00034a-ER for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:24 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:46872 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fQHJf-00034D-7B for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:23 -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 B8CB812592A; Tue, 5 Jun 2018 19:08:22 +0000 (UTC) Received: from dell-per430-12.lab.eng.pek2.redhat.com (dell-per430-12.lab.eng.pek2.redhat.com [10.73.196.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7BB4D2026609; Tue, 5 Jun 2018 19:08:20 +0000 (UTC) From: wexu@redhat.com To: qemu-devel@nongnu.org Date: Tue, 5 Jun 2018 15:07:59 -0400 Message-Id: <1528225683-11413-5-git-send-email-wexu@redhat.com> In-Reply-To: <1528225683-11413-1-git-send-email-wexu@redhat.com> References: <1528225683-11413-1-git-send-email-wexu@redhat.com> 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]); Tue, 05 Jun 2018 19:08:22 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 05 Jun 2018 19:08:22 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'wexu@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [RFC v2 4/8] virtio: get avail bytes check for packed ring X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jasowang@redhat.com, jfreimann@redhat.com, wexu@redhat.com, tiwei.bie@intel.com, mst@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Wei Xu mostly as same as 1.0 except traversing all desc to feed headcount, need a refactor. Signed-off-by: Wei Xu --- hw/virtio/virtio.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 145 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index bd669a2..cdbb5af 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -650,9 +650,9 @@ static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, return VIRTQUEUE_READ_DESC_MORE; } -void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, - unsigned int *out_bytes, - unsigned max_in_bytes, unsigned max_out_bytes) +static void virtqueue_split_get_avail_bytes(VirtQueue *vq, + unsigned int *in_bytes, unsigned int *out_bytes, + unsigned max_in_bytes, unsigned max_out_bytes) { VirtIODevice *vdev = vq->vdev; unsigned int max, idx; @@ -775,6 +775,148 @@ err: goto done; } +static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, + unsigned int *in_bytes, unsigned int *out_bytes, + unsigned max_in_bytes, unsigned max_out_bytes) +{ + VirtIODevice *vdev = vq->vdev; + unsigned int max, idx; + unsigned int total_bufs, in_total, out_total; + MemoryRegionCache *desc_cache; + VRingMemoryRegionCaches *caches; + MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; + int64_t len = 0; + VRingDescPacked desc; + + if (unlikely(!vq->vring.desc)) { + if (in_bytes) { + *in_bytes = 0; + } + if (out_bytes) { + *out_bytes = 0; + } + return; + } + + rcu_read_lock(); + idx = vq->last_avail_idx; + total_bufs = in_total = out_total = 0; + + max = vq->vring.num; + caches = vring_get_region_caches(vq); + if (caches->desc.len < max * sizeof(VRingDescPacked)) { + virtio_error(vdev, "Cannot map descriptor ring"); + goto err; + } + + desc_cache = &caches->desc; + vring_packed_desc_read(vdev, &desc, desc_cache, idx); + while (is_desc_avail(&desc)) { + unsigned int num_bufs; + unsigned int i; + + num_bufs = total_bufs; + + if (desc.flags & VRING_DESC_F_INDIRECT) { + if (desc.len % sizeof(VRingDescPacked)) { + virtio_error(vdev, "Invalid size for indirect buffer table"); + goto err; + } + + /* If we've got too many, that implies a descriptor loop. */ + if (num_bufs >= max) { + virtio_error(vdev, "Looped descriptor"); + goto err; + } + + /* loop over the indirect descriptor table */ + len = address_space_cache_init(&indirect_desc_cache, + vdev->dma_as, + desc.addr, desc.len, false); + desc_cache = &indirect_desc_cache; + if (len < desc.len) { + virtio_error(vdev, "Cannot map indirect buffer"); + goto err; + } + + max = desc.len / sizeof(VRingDescPacked); + num_bufs = i = 0; + vring_packed_desc_read(vdev, &desc, desc_cache, i); + } + + do { + /* If we've got too many, that implies a descriptor loop. */ + if (++num_bufs > max) { + virtio_error(vdev, "Looped descriptor"); + goto err; + } + + if (desc.flags & VRING_DESC_F_WRITE) { + in_total += desc.len; + } else { + out_total += desc.len; + } + if (in_total >= max_in_bytes && out_total >= max_out_bytes) { + goto done; + } + + if (desc_cache == &indirect_desc_cache) { + if (++i >= vq->vring.num) { + i -= vq->vring.num; + } + vring_packed_desc_read(vdev, &desc, desc_cache, i); + } else { + if (++idx >= vq->vring.num) { + idx -= vq->vring.num; + } + vring_packed_desc_read(vdev, &desc, desc_cache, idx); + } + /* Make sure we see the flags */ + smp_mb(); + } while (desc.flags & VRING_DESC_F_NEXT); + + if (desc_cache == &indirect_desc_cache) { + address_space_cache_destroy(&indirect_desc_cache); + total_bufs++; + /* We missed one step on for indirect desc */ + idx++; + } else { + total_bufs = num_bufs; + } + + desc_cache = &caches->desc; + vring_packed_desc_read(vdev, &desc, desc_cache, idx % vq->vring.num); + } + +done: + address_space_cache_destroy(&indirect_desc_cache); + if (in_bytes) { + *in_bytes = in_total; + } + if (out_bytes) { + *out_bytes = out_total; + } + rcu_read_unlock(); + return; + +err: + in_total = out_total = 0; + goto done; +} + +void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, + unsigned int *out_bytes, + unsigned max_in_bytes, unsigned max_out_bytes) +{ + if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { + virtqueue_packed_get_avail_bytes(vq, in_bytes, out_bytes, + max_in_bytes, max_out_bytes); + } else { + virtqueue_split_get_avail_bytes(vq, in_bytes, out_bytes, + max_in_bytes, max_out_bytes); + } +} + int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, unsigned int out_bytes) {