From patchwork Mon Oct 28 16:11:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 11216175 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 6E30F112B for ; Mon, 28 Oct 2019 17:28:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F36DE20862 for ; Mon, 28 Oct 2019 17:28:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EaUtPq/g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F36DE20862 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:37364 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iP8on-0003yn-Lt for patchwork-qemu-devel@patchwork.kernel.org; Mon, 28 Oct 2019 13:28:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37397) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iP7c4-0002eE-JS for qemu-devel@nongnu.org; Mon, 28 Oct 2019 12:11:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iP7c2-00006r-1C for qemu-devel@nongnu.org; Mon, 28 Oct 2019 12:11:23 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:25593 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iP7c1-00006g-Na for qemu-devel@nongnu.org; Mon, 28 Oct 2019 12:11:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572279081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Hnj0hIqd9X1h5X9SAoMPg6K5+65BLNbNQsJXZQt1qNU=; b=EaUtPq/gAxldzqdP/KzvwFb2nMfqkvSh9W3a0A01zu+GdtulbWIqMjJ+9QQYGPykDx+6pn BLAeuTlSrALvAhT6qq0wjNixIx6M8iYanRGAElAqbAcFFsFK8pi9DMdzBzWzKVB/3Xs5ve OEicpDNzpghmGE0oy5WxF5IP9kBQMGk= 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-170-iZfK7TG9M4uO7pOAvCApZw-1; Mon, 28 Oct 2019 12:11:19 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 11E7A180496F for ; Mon, 28 Oct 2019 16:11:19 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-216.ams2.redhat.com [10.36.116.216]) by smtp.corp.redhat.com (Postfix) with ESMTP id DD66A600C9; Mon, 28 Oct 2019 16:11:12 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, mst@redhat.com Subject: [PATCH v2] virtio: Use auto rcu_read macros Date: Mon, 28 Oct 2019 16:11:09 +0000 Message-Id: <20191028161109.60205-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: iZfK7TG9M4uO7pOAvCApZw-1 X-Mimecast-Spam-Score: 0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" Use RCU_READ_LOCK_GUARD and WITH_RCU_READ_LOCK_GUARD to replace the manual rcu_read_(un)lock calls. I think the only change is virtio_load which was missing unlocks in error paths; those end up being fatal errors so it's not that important anyway. Signed-off-by: Dr. David Alan Gilbert --- hw/virtio/virtio.c | 65 ++++++++++++++++------------------------------ 1 file changed, 23 insertions(+), 42 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 2e91dec567..7cb67702d0 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -387,7 +387,8 @@ static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) static void virtio_queue_split_set_notification(VirtQueue *vq, int enable) { - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); + if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { vring_set_avail_event(vq, vring_avail_idx(vq)); } else if (enable) { @@ -399,7 +400,6 @@ static void virtio_queue_split_set_notification(VirtQueue *vq, int enable) /* Expose avail event/used flags before caller checks the avail idx. */ smp_mb(); } - rcu_read_unlock(); } static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) @@ -408,7 +408,7 @@ static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) VRingPackedDescEvent e; VRingMemoryRegionCaches *caches; - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); caches = vring_get_region_caches(vq); vring_packed_event_read(vq->vdev, &caches->used, &e); @@ -429,7 +429,6 @@ static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) /* Expose avail event/used flags before caller checks the avail idx. */ smp_mb(); } - rcu_read_unlock(); } void virtio_queue_set_notification(VirtQueue *vq, int enable) @@ -577,9 +576,8 @@ static int virtio_queue_split_empty(VirtQueue *vq) return 0; } - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); empty = vring_avail_idx(vq) == vq->last_avail_idx; - rcu_read_unlock(); return empty; } @@ -601,12 +599,8 @@ static int virtio_queue_packed_empty_rcu(VirtQueue *vq) static int virtio_queue_packed_empty(VirtQueue *vq) { - bool empty; - - rcu_read_lock(); - empty = virtio_queue_packed_empty_rcu(vq); - rcu_read_unlock(); - return empty; + RCU_READ_LOCK_GUARD(); + return virtio_queue_packed_empty_rcu(vq); } int virtio_queue_empty(VirtQueue *vq) @@ -859,10 +853,9 @@ void virtqueue_flush(VirtQueue *vq, unsigned int count) void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, unsigned int len) { - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); virtqueue_fill(vq, elem, len, 0); virtqueue_flush(vq, 1); - rcu_read_unlock(); } /* Called within rcu_read_lock(). */ @@ -943,7 +936,8 @@ static void virtqueue_split_get_avail_bytes(VirtQueue *vq, int64_t len = 0; int rc; - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); + idx = vq->last_avail_idx; total_bufs = in_total = out_total = 0; @@ -1033,7 +1027,6 @@ done: if (out_bytes) { *out_bytes = out_total; } - rcu_read_unlock(); return; err: @@ -1083,7 +1076,7 @@ static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, VRingPackedDesc desc; bool wrap_counter; - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); idx = vq->last_avail_idx; wrap_counter = vq->last_avail_wrap_counter; total_bufs = in_total = out_total = 0; @@ -1176,7 +1169,6 @@ done: if (out_bytes) { *out_bytes = out_total; } - rcu_read_unlock(); return; err: @@ -1360,7 +1352,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) VRingDesc desc; int rc; - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); if (virtio_queue_empty_rcu(vq)) { goto done; } @@ -1469,7 +1461,6 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); done: address_space_cache_destroy(&indirect_desc_cache); - rcu_read_unlock(); return elem; @@ -1494,7 +1485,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) uint16_t id; int rc; - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); if (virtio_queue_packed_empty_rcu(vq)) { goto done; } @@ -1600,7 +1591,6 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); done: address_space_cache_destroy(&indirect_desc_cache); - rcu_read_unlock(); return elem; @@ -2437,13 +2427,10 @@ static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) { - bool should_notify; - rcu_read_lock(); - should_notify = virtio_should_notify(vdev, vq); - rcu_read_unlock(); - - if (!should_notify) { - return; + WITH_RCU_READ_LOCK_GUARD() { + if (!virtio_should_notify(vdev, vq)) { + return; + } } trace_virtio_notify_irqfd(vdev, vq); @@ -2475,13 +2462,10 @@ static void virtio_irq(VirtQueue *vq) void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) { - bool should_notify; - rcu_read_lock(); - should_notify = virtio_should_notify(vdev, vq); - rcu_read_unlock(); - - if (!should_notify) { - return; + WITH_RCU_READ_LOCK_GUARD() { + if (!virtio_should_notify(vdev, vq)) { + return; + } } trace_virtio_notify(vdev, vq); @@ -3032,7 +3016,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) vdev->start_on_kick = true; } - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); for (i = 0; i < num; i++) { if (vdev->vq[i].vring.desc) { uint16_t nheads; @@ -3087,7 +3071,6 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } } } - rcu_read_unlock(); return 0; } @@ -3290,12 +3273,11 @@ static void virtio_queue_packed_restore_last_avail_idx(VirtIODevice *vdev, static void virtio_queue_split_restore_last_avail_idx(VirtIODevice *vdev, int n) { - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); if (vdev->vq[n].vring.desc) { vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; } - rcu_read_unlock(); } void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) @@ -3315,11 +3297,10 @@ static void virtio_queue_packed_update_used_idx(VirtIODevice *vdev, int n) static void virtio_split_packed_update_used_idx(VirtIODevice *vdev, int n) { - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); if (vdev->vq[n].vring.desc) { vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); } - rcu_read_unlock(); } void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)