From nobody Fri May 3 14:25:21 2024 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 1486629720296259.39828097470706; Thu, 9 Feb 2017 00:42:00 -0800 (PST) Received: from localhost ([::1]:36404 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbkIf-0003Lc-Nh for importer@patchew.org; Thu, 09 Feb 2017 03:41:57 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52739) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbkHh-00034P-QQ for qemu-devel@nongnu.org; Thu, 09 Feb 2017 03:40:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cbkHc-0005LX-MC for qemu-devel@nongnu.org; Thu, 09 Feb 2017 03:40:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40530) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cbkHc-0005LK-Da for qemu-devel@nongnu.org; Thu, 09 Feb 2017 03:40:52 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (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 5216080F94; Thu, 9 Feb 2017 08:40:52 +0000 (UTC) Received: from lemon.redhat.com (ovpn-8-16.pek2.redhat.com [10.72.8.16]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v198enat023679; Thu, 9 Feb 2017 03:40:50 -0500 From: Fam Zheng To: qemu-devel@nongnu.org Date: Thu, 9 Feb 2017 16:40:47 +0800 Message-Id: <20170209084047.7897-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 09 Feb 2017 08:40:52 +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] virtio: Report real progress in VQ aio poll handler 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: Paolo Bonzini , Ed Swierk , Stefan Hajnoczi , "Michael S. Tsirkin" 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" In virtio_queue_host_notifier_aio_poll, not all "!virtio_queue_empty()" cases are making true progress. Currently the offending one is virtio-scsi event queue, whose handler does nothing if no event is pending. As a result aio_poll() will spin on the "non-empty" VQ and take 100% host CPU. Fix this by reporting actual progress from virtio queue aio handlers. Reported-by: Ed Swierk Signed-off-by: Fam Zheng Reviewed-by: Stefan Hajnoczi Tested-by: Ed Swierk --- hw/block/dataplane/virtio-blk.c | 4 ++-- hw/block/virtio-blk.c | 12 ++++++++++-- hw/scsi/virtio-scsi-dataplane.c | 14 +++++++------- hw/scsi/virtio-scsi.c | 14 +++++++++++--- hw/virtio/virtio.c | 15 +++++++++------ include/hw/virtio/virtio-blk.h | 2 +- include/hw/virtio/virtio-scsi.h | 6 +++--- include/hw/virtio/virtio.h | 4 ++-- 8 files changed, 45 insertions(+), 26 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-bl= k.c index d1f9f63..5556f0e 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -147,7 +147,7 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane= *s) g_free(s); } =20 -static void virtio_blk_data_plane_handle_output(VirtIODevice *vdev, +static bool virtio_blk_data_plane_handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOBlock *s =3D (VirtIOBlock *)vdev; @@ -155,7 +155,7 @@ static void virtio_blk_data_plane_handle_output(VirtIOD= evice *vdev, assert(s->dataplane); assert(s->dataplane_started); =20 - virtio_blk_handle_vq(s, vq); + return virtio_blk_handle_vq(s, vq); } =20 /* Context: QEMU global mutex held */ diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 702eda8..baaa195 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -581,10 +581,11 @@ static int virtio_blk_handle_request(VirtIOBlockReq *= req, MultiReqBuffer *mrb) return 0; } =20 -void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) +bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) { VirtIOBlockReq *req; MultiReqBuffer mrb =3D {}; + bool progress =3D false; =20 blk_io_plug(s->blk); =20 @@ -592,6 +593,7 @@ void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) virtio_queue_set_notification(vq, 0); =20 while ((req =3D virtio_blk_get_request(s, vq))) { + progress =3D true; if (virtio_blk_handle_request(req, &mrb)) { virtqueue_detach_element(req->vq, &req->elem, 0); virtio_blk_free_request(req); @@ -607,6 +609,12 @@ void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *v= q) } =20 blk_io_unplug(s->blk); + return progress; +} + +static void virtio_blk_handle_output_do(VirtIOBlock *s, VirtQueue *vq) +{ + virtio_blk_handle_vq(s, vq); } =20 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) @@ -622,7 +630,7 @@ static void virtio_blk_handle_output(VirtIODevice *vdev= , VirtQueue *vq) return; } } - virtio_blk_handle_vq(s, vq); + virtio_blk_handle_output_do(s, vq); } =20 static void virtio_blk_dma_restart_bh(void *opaque) diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplan= e.c index 6b8d0f0..74c95e0 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -49,35 +49,35 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error *= *errp) } } =20 -static void virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev, +static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSCSI *s =3D (VirtIOSCSI *)vdev; =20 assert(s->ctx && s->dataplane_started); - virtio_scsi_handle_cmd_vq(s, vq); + return virtio_scsi_handle_cmd_vq(s, vq); } =20 -static void virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev, +static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSCSI *s =3D VIRTIO_SCSI(vdev); =20 assert(s->ctx && s->dataplane_started); - virtio_scsi_handle_ctrl_vq(s, vq); + return virtio_scsi_handle_ctrl_vq(s, vq); } =20 -static void virtio_scsi_data_plane_handle_event(VirtIODevice *vdev, +static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSCSI *s =3D VIRTIO_SCSI(vdev); =20 assert(s->ctx && s->dataplane_started); - virtio_scsi_handle_event_vq(s, vq); + return virtio_scsi_handle_event_vq(s, vq); } =20 static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n, - void (*fn)(VirtIODevice *vdev, VirtQueue= *vq)) + VirtIOHandleAIOOutput fn) { BusState *qbus =3D BUS(qdev_get_parent_bus(DEVICE(s))); int rc; diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index ce19eff..b01030b 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -436,13 +436,16 @@ static inline void virtio_scsi_release(VirtIOSCSI *s) } } =20 -void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq) +bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq) { VirtIOSCSIReq *req; + bool progress =3D false; =20 while ((req =3D virtio_scsi_pop_req(s, vq))) { + progress =3D true; virtio_scsi_handle_ctrl_req(s, req); } + return progress; } =20 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) @@ -591,10 +594,11 @@ static void virtio_scsi_handle_cmd_req_submit(VirtIOS= CSI *s, VirtIOSCSIReq *req) scsi_req_unref(sreq); } =20 -void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq) +bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq) { VirtIOSCSIReq *req, *next; int ret =3D 0; + bool progress =3D false; =20 QTAILQ_HEAD(, VirtIOSCSIReq) reqs =3D QTAILQ_HEAD_INITIALIZER(reqs); =20 @@ -602,6 +606,7 @@ void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue= *vq) virtio_queue_set_notification(vq, 0); =20 while ((req =3D virtio_scsi_pop_req(s, vq))) { + progress =3D true; ret =3D virtio_scsi_handle_cmd_req_prepare(s, req); if (!ret) { QTAILQ_INSERT_TAIL(&reqs, req, next); @@ -624,6 +629,7 @@ void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue= *vq) QTAILQ_FOREACH_SAFE(req, &reqs, next, next) { virtio_scsi_handle_cmd_req_submit(s, req); } + return progress; } =20 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) @@ -752,11 +758,13 @@ out: virtio_scsi_release(s); } =20 -void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq) +bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq) { if (s->events_dropped) { virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0); + return true; } + return false; } =20 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 6365706..2461c06 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -97,7 +97,7 @@ struct VirtQueue =20 uint16_t vector; VirtIOHandleOutput handle_output; - VirtIOHandleOutput handle_aio_output; + VirtIOHandleAIOOutput handle_aio_output; VirtIODevice *vdev; EventNotifier guest_notifier; EventNotifier host_notifier; @@ -1287,14 +1287,16 @@ void virtio_queue_set_align(VirtIODevice *vdev, int= n, int align) virtio_queue_update_rings(vdev, n); } =20 -static void virtio_queue_notify_aio_vq(VirtQueue *vq) +static bool virtio_queue_notify_aio_vq(VirtQueue *vq) { if (vq->vring.desc && vq->handle_aio_output) { VirtIODevice *vdev =3D vq->vdev; =20 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); - vq->handle_aio_output(vdev, vq); + return vq->handle_aio_output(vdev, vq); } + + return false; } =20 static void virtio_queue_notify_vq(VirtQueue *vq) @@ -2125,16 +2127,17 @@ static bool virtio_queue_host_notifier_aio_poll(voi= d *opaque) { EventNotifier *n =3D opaque; VirtQueue *vq =3D container_of(n, VirtQueue, host_notifier); + bool progress; =20 if (virtio_queue_empty(vq)) { return false; } =20 - virtio_queue_notify_aio_vq(vq); + progress =3D virtio_queue_notify_aio_vq(vq); =20 /* In case the handler function re-enabled notifications */ virtio_queue_set_notification(vq, 0); - return true; + return progress; } =20 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) @@ -2146,7 +2149,7 @@ static void virtio_queue_host_notifier_aio_poll_end(E= ventNotifier *n) } =20 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext = *ctx, - VirtIOHandleOutput handle_= output) + VirtIOHandleAIOOutput hand= le_output) { if (handle_output) { vq->handle_aio_output =3D handle_output; diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index 9734b4c..d3c8a6f 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -80,6 +80,6 @@ typedef struct MultiReqBuffer { bool is_write; } MultiReqBuffer; =20 -void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq); +bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq); =20 #endif diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scs= i.h index 7375196..f536f77 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -126,9 +126,9 @@ void virtio_scsi_common_realize(DeviceState *dev, Error= **errp, VirtIOHandleOutput cmd); =20 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp); -void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq); -void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq); -void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq); +bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq); +bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq); +bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq); void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req= ); void virtio_scsi_free_req(VirtIOSCSIReq *req); void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev, diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 525da24..0863a25 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -154,6 +154,7 @@ void virtio_error(VirtIODevice *vdev, const char *fmt, = ...) GCC_FMT_ATTR(2, 3); void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name); =20 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *); +typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *); =20 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, VirtIOHandleOutput handle_output); @@ -284,8 +285,7 @@ bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev= ); EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); void virtio_queue_host_notifier_read(EventNotifier *n); void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext = *ctx, - void (*fn)(VirtIODevice *, - VirtQueue *)); + VirtIOHandleAIOOutput hand= le_output); VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector); VirtQueue *virtio_vector_next_queue(VirtQueue *vq); =20 --=20 2.9.3