From nobody Thu May 2 13:47:33 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1572283750; cv=none; d=zoho.com; s=zohoarc; b=fxvOaIw4ZNUKuqYbZtkEJd2jjDAiM5z5TCwJh4QvVvZv5fyJZlxIILsOy/YNLnqSAaRjrjKMqaf2sR4ZTUtDhJeaG4MJ+j2wKFLelFuR6DbM/aFX65Nzd/6MCjaPqK+xZRMeX7OJCbJlpgUUZaKyVzAsNL7aAvTwkOG7dQG9+aI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1572283750; h=Content-Type:Content-Transfer-Encoding:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To; bh=Hnj0hIqd9X1h5X9SAoMPg6K5+65BLNbNQsJXZQt1qNU=; b=MCpYbXTki4LQ3h5+G3Sxbhl7CCd/XrqNHIHxXEXoKDtKwiwgdu6WrSOYiUA+HHB5uTRRq/61Xnr3wYaW+rAk7i3e6UKxVDX/8dmiQ65QtLT4KfG4O8wzh1edPceeRCbY3h5hMLR/hh4fCO8VyXk8um7rO85Xdfg+/ZkJB25BbaA= ARC-Authentication-Results: i=1; mx.zoho.com; dkim=pass; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1572283750469339.76577417938813; Mon, 28 Oct 2019 10:29:10 -0700 (PDT) Received: from localhost ([::1]:37364 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iP8pI-0003yn-B5 for importer@patchew.org; Mon, 28 Oct 2019 13:29:08 -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 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) 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= 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 Content-Transfer-Encoding: quoted-printable 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" 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) =20 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(VirtQue= ue *vq, int enable) /* Expose avail event/used flags before caller checks the avail id= x. */ smp_mb(); } - rcu_read_unlock(); } =20 static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) @@ -408,7 +408,7 @@ static void virtio_queue_packed_set_notification(VirtQu= eue *vq, int enable) VRingPackedDescEvent e; VRingMemoryRegionCaches *caches; =20 - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); caches =3D vring_get_region_caches(vq); vring_packed_event_read(vq->vdev, &caches->used, &e); =20 @@ -429,7 +429,6 @@ static void virtio_queue_packed_set_notification(VirtQu= eue *vq, int enable) /* Expose avail event/used flags before caller checks the avail id= x. */ smp_mb(); } - rcu_read_unlock(); } =20 void virtio_queue_set_notification(VirtQueue *vq, int enable) @@ -577,9 +576,8 @@ static int virtio_queue_split_empty(VirtQueue *vq) return 0; } =20 - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); empty =3D vring_avail_idx(vq) =3D=3D vq->last_avail_idx; - rcu_read_unlock(); return empty; } =20 @@ -601,12 +599,8 @@ static int virtio_queue_packed_empty_rcu(VirtQueue *vq) =20 static int virtio_queue_packed_empty(VirtQueue *vq) { - bool empty; - - rcu_read_lock(); - empty =3D virtio_queue_packed_empty_rcu(vq); - rcu_read_unlock(); - return empty; + RCU_READ_LOCK_GUARD(); + return virtio_queue_packed_empty_rcu(vq); } =20 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(); } =20 /* Called within rcu_read_lock(). */ @@ -943,7 +936,8 @@ static void virtqueue_split_get_avail_bytes(VirtQueue *= vq, int64_t len =3D 0; int rc; =20 - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); + idx =3D vq->last_avail_idx; total_bufs =3D in_total =3D out_total =3D 0; =20 @@ -1033,7 +1027,6 @@ done: if (out_bytes) { *out_bytes =3D out_total; } - rcu_read_unlock(); return; =20 err: @@ -1083,7 +1076,7 @@ static void virtqueue_packed_get_avail_bytes(VirtQueu= e *vq, VRingPackedDesc desc; bool wrap_counter; =20 - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); idx =3D vq->last_avail_idx; wrap_counter =3D vq->last_avail_wrap_counter; total_bufs =3D in_total =3D out_total =3D 0; @@ -1176,7 +1169,6 @@ done: if (out_bytes) { *out_bytes =3D out_total; } - rcu_read_unlock(); return; =20 err: @@ -1360,7 +1352,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_= t sz) VRingDesc desc; int rc; =20 - 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(); =20 return elem; =20 @@ -1494,7 +1485,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size= _t sz) uint16_t id; int rc; =20 - 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(); =20 return elem; =20 @@ -2437,13 +2427,10 @@ static bool virtio_should_notify(VirtIODevice *vdev= , VirtQueue *vq) =20 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) { - bool should_notify; - rcu_read_lock(); - should_notify =3D virtio_should_notify(vdev, vq); - rcu_read_unlock(); - - if (!should_notify) { - return; + WITH_RCU_READ_LOCK_GUARD() { + if (!virtio_should_notify(vdev, vq)) { + return; + } } =20 trace_virtio_notify_irqfd(vdev, vq); @@ -2475,13 +2462,10 @@ static void virtio_irq(VirtQueue *vq) =20 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) { - bool should_notify; - rcu_read_lock(); - should_notify =3D virtio_should_notify(vdev, vq); - rcu_read_unlock(); - - if (!should_notify) { - return; + WITH_RCU_READ_LOCK_GUARD() { + if (!virtio_should_notify(vdev, vq)) { + return; + } } =20 trace_virtio_notify(vdev, vq); @@ -3032,7 +3016,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int = version_id) vdev->start_on_kick =3D true; } =20 - rcu_read_lock(); + RCU_READ_LOCK_GUARD(); for (i =3D 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(); =20 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 =3D vring_used_idx(&vdev->vq[n]); vdev->vq[n].shadow_avail_idx =3D vdev->vq[n].last_avail_idx; } - rcu_read_unlock(); } =20 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) @@ -3315,11 +3297,10 @@ static void virtio_queue_packed_update_used_idx(Vir= tIODevice *vdev, int n) =20 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 =3D vring_used_idx(&vdev->vq[n]); } - rcu_read_unlock(); } =20 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) --=20 2.23.0