From patchwork Wed Apr 12 13:53:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 750019 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3w356B0mPMz9sD5 for ; Wed, 12 Apr 2017 23:55:30 +1000 (AEST) Received: from localhost ([::1]:44425 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cyIk3-0008W2-MZ for incoming@patchwork.ozlabs.org; Wed, 12 Apr 2017 09:55:27 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60353) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cyIi5-00079V-4x for qemu-devel@nongnu.org; Wed, 12 Apr 2017 09:53:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cyIi4-0004d0-8q for qemu-devel@nongnu.org; Wed, 12 Apr 2017 09:53:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54652) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cyIi3-0004ca-VQ for qemu-devel@nongnu.org; Wed, 12 Apr 2017 09:53:24 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D00AA7AEA5; Wed, 12 Apr 2017 13:53:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com D00AA7AEA5 Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=lvivier@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com D00AA7AEA5 Received: from thinkpad.redhat.com (ovpn-116-243.ams2.redhat.com [10.36.116.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 54E28173E5; Wed, 12 Apr 2017 13:53:21 +0000 (UTC) From: Laurent Vivier To: "Dr . David Alan Gilbert" Date: Wed, 12 Apr 2017 15:53:12 +0200 Message-Id: <20170412135312.1686-3-lvivier@redhat.com> In-Reply-To: <20170412135312.1686-1-lvivier@redhat.com> References: <20170412135312.1686-1-lvivier@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Wed, 12 Apr 2017 13:53:23 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 2/2] virtio-rng: stop virtqueue while the CPU is stopped 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: Amit Shah , qemu-devel@nongnu.org, Stefan Hajnoczi , "Michael S . Tsirkin" Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" If we modify the virtio-rng virqueue while the vmstate is already migrated we can have some inconsistencies between the virtqueue state and the memory content. To avoid this, stop the virtqueue while the CPU is stopped. Signed-off-by: Laurent Vivier Reviewed-by: Juan Quintela --- hw/virtio/trace-events | 3 +++ hw/virtio/virtio-rng.c | 29 +++++++++++++++++++++++------ include/hw/virtio/virtio-rng.h | 2 ++ 3 files changed, 28 insertions(+), 6 deletions(-) diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events index 6926eed..1f7a7c1 100644 --- a/hw/virtio/trace-events +++ b/hw/virtio/trace-events @@ -11,8 +11,11 @@ virtio_set_status(void *vdev, uint8_t val) "vdev %p val %u" # hw/virtio/virtio-rng.c virtio_rng_guest_not_ready(void *rng) "rng %p: guest not ready" +virtio_rng_cpu_is_stopped(void *rng, int size) "rng %p: cpu is stopped, dropping %d bytes" +virtio_rng_popped(void *rng) "rng %p: elem popped" virtio_rng_pushed(void *rng, size_t len) "rng %p: %zd bytes pushed" virtio_rng_request(void *rng, size_t size, unsigned quota) "rng %p: %zd bytes requested, %u bytes quota left" +virtio_rng_vm_state_change(void *rng, int running, int state) "rng %p: state change to running %d state %d" # hw/virtio/virtio-balloon.c # diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c index 9639f4e..a6ee501 100644 --- a/hw/virtio/virtio-rng.c +++ b/hw/virtio/virtio-rng.c @@ -53,6 +53,15 @@ static void chr_read(void *opaque, const void *buf, size_t size) return; } + /* we can't modify the virtqueue until + * our state is fully synced + */ + + if (!runstate_check(RUN_STATE_RUNNING)) { + trace_virtio_rng_cpu_is_stopped(vrng, size); + return; + } + vrng->quota_remaining -= size; offset = 0; @@ -61,6 +70,7 @@ static void chr_read(void *opaque, const void *buf, size_t size) if (!elem) { break; } + trace_virtio_rng_popped(vrng); len = iov_from_buf(elem->in_sg, elem->in_num, 0, buf + offset, size - offset); offset += len; @@ -120,17 +130,21 @@ static uint64_t get_features(VirtIODevice *vdev, uint64_t f, Error **errp) return f; } -static int virtio_rng_post_load(void *opaque, int version_id) +static void virtio_rng_vm_state_change(void *opaque, int running, + RunState state) { VirtIORNG *vrng = opaque; + trace_virtio_rng_vm_state_change(vrng, running, state); + /* We may have an element ready but couldn't process it due to a quota - * limit. Make sure to try again after live migration when the quota may - * have been reset. + * limit or because CPU was stopped. Make sure to try again when the + * CPU restart. */ - virtio_rng_process(vrng); - return 0; + if (running && is_guest_ready(vrng)) { + virtio_rng_process(vrng); + } } static void check_rate_limit(void *opaque) @@ -198,6 +212,9 @@ static void virtio_rng_device_realize(DeviceState *dev, Error **errp) vrng->rate_limit_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, check_rate_limit, vrng); vrng->activate_timer = true; + + vrng->vmstate = qemu_add_vm_change_state_handler(virtio_rng_vm_state_change, + vrng); } static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp) @@ -205,6 +222,7 @@ static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp) VirtIODevice *vdev = VIRTIO_DEVICE(dev); VirtIORNG *vrng = VIRTIO_RNG(dev); + qemu_del_vm_change_state_handler(vrng->vmstate); timer_del(vrng->rate_limit_timer); timer_free(vrng->rate_limit_timer); virtio_cleanup(vdev); @@ -218,7 +236,6 @@ static const VMStateDescription vmstate_virtio_rng = { VMSTATE_VIRTIO_DEVICE, VMSTATE_END_OF_LIST() }, - .post_load = virtio_rng_post_load, }; static Property virtio_rng_properties[] = { diff --git a/include/hw/virtio/virtio-rng.h b/include/hw/virtio/virtio-rng.h index 2d40abd..922dce7 100644 --- a/include/hw/virtio/virtio-rng.h +++ b/include/hw/virtio/virtio-rng.h @@ -45,6 +45,8 @@ typedef struct VirtIORNG { QEMUTimer *rate_limit_timer; int64_t quota_remaining; bool activate_timer; + + VMChangeStateEntry *vmstate; } VirtIORNG; #endif