From nobody Sat Feb 7 06:55:37 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1492778867599992.744203165606; Fri, 21 Apr 2017 05:47:47 -0700 (PDT) Received: from localhost ([::1]:59115 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1XyT-0002wM-VW for importer@patchew.org; Fri, 21 Apr 2017 08:47:46 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46048) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1XDA-0003ZV-DA for qemu-devel@nongnu.org; Fri, 21 Apr 2017 07:58:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d1XD9-0007v1-Go for qemu-devel@nongnu.org; Fri, 21 Apr 2017 07:58:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50720) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d1XD9-0007ue-7Y for qemu-devel@nongnu.org; Fri, 21 Apr 2017 07:58:51 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1D07E6E795 for ; Fri, 21 Apr 2017 11:58:50 +0000 (UTC) Received: from secure.com (ovpn-116-35.ams2.redhat.com [10.36.116.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id EC5B389F51; Fri, 21 Apr 2017 11:58:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 1D07E6E795 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=quintela@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 1D07E6E795 From: Juan Quintela To: qemu-devel@nongnu.org Date: Fri, 21 Apr 2017 13:56:42 +0200 Message-Id: <20170421115646.15544-62-quintela@redhat.com> In-Reply-To: <20170421115646.15544-1-quintela@redhat.com> References: <20170421115646.15544-1-quintela@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 21 Apr 2017 11:58:50 +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] [PULL 61/65] 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: Laurent Vivier , dgilbert@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Laurent Vivier 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: Amit Shah Reviewed-by: Stefan Hajnoczi Reviewed-by: Juan Quintela Signed-off-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" =20 # 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, dr= opping %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 by= tes requested, %u bytes quota left" +virtio_rng_vm_state_change(void *rng, int running, int state) "rng %p: sta= te change to running %d state %d" =20 # 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; } =20 + /* 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 -=3D size; =20 offset =3D 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 =3D iov_from_buf(elem->in_sg, elem->in_num, 0, buf + offset, size - offset); offset +=3D len; @@ -120,17 +130,21 @@ static uint64_t get_features(VirtIODevice *vdev, uint= 64_t f, Error **errp) return f; } =20 -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 =3D opaque; =20 + 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); =20 - return 0; + if (running && is_guest_ready(vrng)) { + virtio_rng_process(vrng); + } } =20 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 =3D timer_new_ms(QEMU_CLOCK_VIRTUAL, check_rate_limit, vrng); vrng->activate_timer =3D true; + + vrng->vmstate =3D qemu_add_vm_change_state_handler(virtio_rng_vm_state= _change, + vrng); } =20 static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp) @@ -205,6 +222,7 @@ static void virtio_rng_device_unrealize(DeviceState *de= v, Error **errp) VirtIODevice *vdev =3D VIRTIO_DEVICE(dev); VirtIORNG *vrng =3D VIRTIO_RNG(dev); =20 + 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 =3D { VMSTATE_VIRTIO_DEVICE, VMSTATE_END_OF_LIST() }, - .post_load =3D virtio_rng_post_load, }; =20 static Property virtio_rng_properties[] =3D { 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; =20 #endif --=20 2.9.3