From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BCB1C17440 for ; Tue, 12 Nov 2019 11:14:59 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 25B692084E for ; Tue, 12 Nov 2019 11:14:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25B692084E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33428 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iUU8Q-00028c-7d for qemu-devel@archiver.kernel.org; Tue, 12 Nov 2019 06:14:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33138) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iUU7h-0001Hi-5G for qemu-devel@nongnu.org; Tue, 12 Nov 2019 06:14:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iUU7e-0002oY-Tv for qemu-devel@nongnu.org; Tue, 12 Nov 2019 06:14:12 -0500 Received: from relay.sw.ru ([185.231.240.75]:37396) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iUU7e-0002o0-KT for qemu-devel@nongnu.org; Tue, 12 Nov 2019 06:14:10 -0500 Received: from dptest2.qa.sw.ru ([10.94.4.71]) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1iUU7W-00008X-0X; Tue, 12 Nov 2019 14:14:02 +0300 From: Denis Plotnikov To: qemu-devel@nongnu.org Subject: [PATCH v3 1/2] virtio: make seg_max virtqueue size dependent Date: Tue, 12 Nov 2019 14:13:53 +0300 Message-Id: <20191112111354.26324-2-dplotnikov@virtuozzo.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20191112111354.26324-1-dplotnikov@virtuozzo.com> References: <20191112111354.26324-1-dplotnikov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 185.231.240.75 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: , Cc: kwolf@redhat.com, fam@euphon.net, ehabkost@redhat.com, mst@redhat.com, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, den@virtuozzo.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Before the patch, seg_max parameter was immutable and hardcoded to 126 (128 - 2) without respect to queue size. This has two negative effects: 1. when queue size is < 128, we have Virtio 1.1 specfication violation: (2.6.5.3.1 Driver Requirements) seq_max must be <= queue_size. This violation affects the old Linux guests (ver < 4.14). These guests crash on these queue_size setups. 2. when queue_size > 128, as was pointed out by Denis Lunev , seg_max restrics guest's block request length which affects guests' performance making them issues more block request than needed. https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg03721.html To mitigate this two effects, the patch adds the property adjusting seg_max to queue size automaticaly. Since seg_max is a guest visible parameter, the property is machine type managable and allows to choose between old (seg_max = 126 always) and new (seg_max = queue_size - 2) behaviors. Not to change the behavior of the older VMs, prevent setting the default seg_max_adjust value for older machine types. Signed-off-by: Denis Plotnikov --- hw/block/virtio-blk.c | 9 ++++++++- hw/core/machine.c | 3 +++ hw/scsi/vhost-scsi.c | 2 ++ hw/scsi/virtio-scsi.c | 10 +++++++++- include/hw/virtio/virtio-blk.h | 1 + include/hw/virtio/virtio-scsi.h | 1 + 6 files changed, 24 insertions(+), 2 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 4c357d2928..f118b29c7c 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -908,7 +908,8 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) blk_get_geometry(s->blk, &capacity); memset(&blkcfg, 0, sizeof(blkcfg)); virtio_stq_p(vdev, &blkcfg.capacity, capacity); - virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2); + virtio_stl_p(vdev, &blkcfg.seg_max, + s->conf.seg_max_adjust ? s->conf.queue_size - 2 : 128 - 2); virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls); virtio_stl_p(vdev, &blkcfg.blk_size, blk_size); virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size); @@ -1131,6 +1132,11 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) error_setg(errp, "num-queues property must be larger than 0"); return; } + if (conf->queue_size <= 2) { + error_setg(errp, "invalid queue-size property (%" PRIu16 "), " + "must be > 2", conf->queue_size); + return; + } if (!is_power_of_2(conf->queue_size) || conf->queue_size > VIRTQUEUE_MAX_SIZE) { error_setg(errp, "invalid queue-size property (%" PRIu16 "), " @@ -1260,6 +1266,7 @@ static Property virtio_blk_properties[] = { true), DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1), DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128), + DEFINE_PROP_BOOL("seg-max-adjust", VirtIOBlock, conf.seg_max_adjust, true), DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, IOThread *), DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, diff --git a/hw/core/machine.c b/hw/core/machine.c index 1689ad3bf8..3e7df94620 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -29,6 +29,9 @@ GlobalProperty hw_compat_4_1[] = { { "virtio-pci", "x-pcie-flr-init", "off" }, + { "virtio-blk-device", "seg-max-adjust", "off"}, + { "virtio-scsi-device", "seg_max_adjust", "off"}, + { "vhost-blk-device", "seg_max_adjust", "off"}, }; const size_t hw_compat_4_1_len = G_N_ELEMENTS(hw_compat_4_1); diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c index c693fc748a..26f710d3ec 100644 --- a/hw/scsi/vhost-scsi.c +++ b/hw/scsi/vhost-scsi.c @@ -275,6 +275,8 @@ static Property vhost_scsi_properties[] = { DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1), DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size, 128), + DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust, + true), DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors, 0xFFFF), DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128), diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index e8b2b64d09..405cb6c953 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -654,7 +654,8 @@ static void virtio_scsi_get_config(VirtIODevice *vdev, VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev); virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues); - virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2); + virtio_stl_p(vdev, &scsiconf->seg_max, + s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2); virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors); virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun); virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent)); @@ -893,6 +894,11 @@ void virtio_scsi_common_realize(DeviceState *dev, virtio_cleanup(vdev); return; } + if (s->conf.virtqueue_size <= 2) { + error_setg(errp, "invalid virtqueue_size property (= %" PRIu16 "), " + "must be > 2", s->conf.virtqueue_size); + return; + } s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues); s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE; s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE; @@ -949,6 +955,8 @@ static Property virtio_scsi_properties[] = { DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1), DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI, parent_obj.conf.virtqueue_size, 128), + DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI, + parent_obj.conf.seg_max_adjust, true), DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors, 0xFFFF), DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun, diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index cddcfbebe9..2934426050 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -38,6 +38,7 @@ struct VirtIOBlkConf uint32_t request_merging; uint16_t num_queues; uint16_t queue_size; + bool seg_max_adjust; uint32_t max_discard_sectors; uint32_t max_write_zeroes_sectors; }; diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index 122f7c4b6f..24e768909d 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -48,6 +48,7 @@ typedef struct virtio_scsi_config VirtIOSCSIConfig; struct VirtIOSCSIConf { uint32_t num_queues; uint32_t virtqueue_size; + bool seg_max_adjust; uint32_t max_sectors; uint32_t cmd_per_lun; #ifdef CONFIG_VHOST_SCSI -- 2.17.0