From patchwork Tue Jun 28 13:23:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 9203239 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4B59B60752 for ; Tue, 28 Jun 2016 13:26:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3AD782859C for ; Tue, 28 Jun 2016 13:26:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2D67B285C3; Tue, 28 Jun 2016 13:26:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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 mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C044F2859C for ; Tue, 28 Jun 2016 13:26:08 +0000 (UTC) Received: from localhost ([::1]:36729 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHt1j-0002Pz-Qx for patchwork-qemu-devel@patchwork.kernel.org; Tue, 28 Jun 2016 09:26:07 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39318) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHt1B-0002Nz-4T for qemu-devel@nongnu.org; Tue, 28 Jun 2016 09:25:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bHt19-0007uy-Sg for qemu-devel@nongnu.org; Tue, 28 Jun 2016 09:25:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33053) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHt19-0007ui-KB for qemu-devel@nongnu.org; Tue, 28 Jun 2016 09:25:31 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2D76E7F6B4; Tue, 28 Jun 2016 13:25:31 +0000 (UTC) Received: from localhost (ovpn-112-80.ams2.redhat.com [10.36.112.80]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5SDPTXP018263; Tue, 28 Jun 2016 09:25:30 -0400 From: Stefan Hajnoczi To: Date: Tue, 28 Jun 2016 14:23:26 +0100 Message-Id: <1467120211-26495-5-git-send-email-stefanha@redhat.com> In-Reply-To: <1467120211-26495-1-git-send-email-stefanha@redhat.com> References: <1467120211-26495-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 28 Jun 2016 13:25:31 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 4/9] virtio-blk: multiqueue batch notify 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: Peter Maydell , Stefan Hajnoczi Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The batch notification BH needs to know which virtqueues to notify when multiqueue is enabled. Use a bitmap to track the virtqueues with pending notifications. At this point there is only one virtqueue so hard-code virtqueue index 0. A later patch will switch to real virtqueue indices. Signed-off-by: Stefan Hajnoczi Reviewed-by: Fam Zheng Message-id: 1466511196-12612-3-git-send-email-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- hw/block/dataplane/virtio-blk.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 2041b04..c20a195 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -34,8 +34,8 @@ struct VirtIOBlockDataPlane { VirtIODevice *vdev; VirtQueue *vq; /* virtqueue vring */ - EventNotifier *guest_notifier; /* irq */ QEMUBH *bh; /* bh for guest notification */ + unsigned long *batch_notify_vqs; /* Note that these EventNotifiers are assigned by value. This is * fine as long as you do not call event_notifier_cleanup on them @@ -49,18 +49,34 @@ struct VirtIOBlockDataPlane { /* Raise an interrupt to signal guest, if necessary */ void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s) { + set_bit(0, s->batch_notify_vqs); qemu_bh_schedule(s->bh); } static void notify_guest_bh(void *opaque) { VirtIOBlockDataPlane *s = opaque; + unsigned nvqs = s->conf->num_queues; + unsigned long bitmap[BITS_TO_LONGS(nvqs)]; + unsigned j; - if (!virtio_should_notify(s->vdev, s->vq)) { - return; + memcpy(bitmap, s->batch_notify_vqs, sizeof(bitmap)); + memset(s->batch_notify_vqs, 0, sizeof(bitmap)); + + for (j = 0; j < nvqs; j += BITS_PER_LONG) { + unsigned long bits = bitmap[j]; + + while (bits != 0) { + unsigned i = j + ctzl(bits); + VirtQueue *vq = virtio_get_queue(s->vdev, i); + + if (virtio_should_notify(s->vdev, vq)) { + event_notifier_set(virtio_queue_get_guest_notifier(vq)); + } + + bits &= bits - 1; /* clear right-most bit */ + } } - - event_notifier_set(s->guest_notifier); } /* Context: QEMU global mutex held */ @@ -104,6 +120,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf, } s->ctx = iothread_get_aio_context(s->iothread); s->bh = aio_bh_new(s->ctx, notify_guest_bh, s); + s->batch_notify_vqs = bitmap_new(conf->num_queues); *dataplane = s; } @@ -116,6 +133,7 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s) } virtio_blk_data_plane_stop(s); + g_free(s->batch_notify_vqs); qemu_bh_delete(s->bh); object_unref(OBJECT(s->iothread)); g_free(s); @@ -154,7 +172,6 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s) "ensure -enable-kvm is set\n", r); goto fail_guest_notifiers; } - s->guest_notifier = virtio_queue_get_guest_notifier(s->vq); /* Set up virtqueue notify */ r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 0, true);