From nobody Tue Feb 10 15:46:25 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (209.51.188.17 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1550745430222969.321189152253; Thu, 21 Feb 2019 02:37:10 -0800 (PST) Received: from localhost ([127.0.0.1]:57884 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwliq-0000xi-Qy for importer@patchew.org; Thu, 21 Feb 2019 05:36:56 -0500 Received: from eggs.gnu.org ([209.51.188.92]:55751) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwlgY-0007xM-DD for qemu-devel@nongnu.org; Thu, 21 Feb 2019 05:34:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gwlgX-0004XB-Co for qemu-devel@nongnu.org; Thu, 21 Feb 2019 05:34:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39976) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gwlgQ-00047W-1J; Thu, 21 Feb 2019 05:34:27 -0500 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 99E0730833B5; Thu, 21 Feb 2019 10:33:55 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-117-132.ams2.redhat.com [10.36.117.132]) by smtp.corp.redhat.com (Postfix) with ESMTP id 76F7860BE6; Thu, 21 Feb 2019 10:33:52 +0000 (UTC) From: Stefano Garzarella To: qemu-devel@nongnu.org Date: Thu, 21 Feb 2019 11:33:09 +0100 Message-Id: <20190221103314.58500-6-sgarzare@redhat.com> In-Reply-To: <20190221103314.58500-1-sgarzare@redhat.com> References: <20190221103314.58500-1-sgarzare@redhat.com> MIME-Version: 1.0 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 [10.5.110.44]); Thu, 21 Feb 2019 10:33:55 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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] [PATCH v6 05/10] virtio-blk: set config size depending on the features enabled 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 , Kevin Wolf , Thomas Huth , Eduardo Habkost , qemu-block@nongnu.org, "Michael S. Tsirkin" , Jason Wang , "Dr . David Alan Gilbert" , Stefan Hajnoczi , Paolo Bonzini , Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Starting from DISABLE and WRITE_ZEROES features, we use an array of VirtIOFeature (as virtio-net) to properly set the config size depending on the features enabled. Reviewed-by: Stefan Hajnoczi Signed-off-by: Stefano Garzarella --- hw/block/virtio-blk.c | 31 +++++++++++++++++++++++++------ include/hw/virtio/virtio-blk.h | 1 + 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index f7cd322811..8798d13bc4 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -28,9 +28,28 @@ #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" =20 -/* We don't support discard yet, hide associated config fields. */ +/* Config size before the discard support (hide associated config fields) = */ #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \ max_discard_sectors) +/* + * Starting from the discard feature, we can use this array to properly + * set the config size depending on the features enabled. + */ +static VirtIOFeature feature_sizes[] =3D { + {.flags =3D 1ULL << VIRTIO_BLK_F_DISCARD, + .end =3D virtio_endof(struct virtio_blk_config, discard_sector_alignm= ent)}, + {.flags =3D 1ULL << VIRTIO_BLK_F_WRITE_ZEROES, + .end =3D virtio_endof(struct virtio_blk_config, write_zeroes_may_unma= p)}, + {} +}; + +static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_featu= res) +{ + s->config_size =3D MAX(VIRTIO_BLK_CFG_SIZE, + virtio_feature_get_config_size(feature_sizes, host_features)); + + assert(s->config_size <=3D sizeof(struct virtio_blk_config)); +} =20 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, VirtIOBlockReq *req) @@ -763,8 +782,7 @@ static void virtio_blk_update_config(VirtIODevice *vdev= , uint8_t *config) blkcfg.alignment_offset =3D 0; blkcfg.wce =3D blk_enable_write_cache(s->blk); virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); - memcpy(config, &blkcfg, VIRTIO_BLK_CFG_SIZE); - QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg)); + memcpy(config, &blkcfg, s->config_size); } =20 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *confi= g) @@ -772,8 +790,7 @@ static void virtio_blk_set_config(VirtIODevice *vdev, c= onst uint8_t *config) VirtIOBlock *s =3D VIRTIO_BLK(vdev); struct virtio_blk_config blkcfg; =20 - memcpy(&blkcfg, config, VIRTIO_BLK_CFG_SIZE); - QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg)); + memcpy(&blkcfg, config, s->config_size); =20 aio_context_acquire(blk_get_aio_context(s->blk)); blk_set_enable_write_cache(s->blk, blkcfg.wce !=3D 0); @@ -956,7 +973,9 @@ static void virtio_blk_device_realize(DeviceState *dev,= Error **errp) return; } =20 - virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE); + virtio_blk_set_config_size(s, s->host_features); + + virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, s->config_size); =20 s->blk =3D conf->conf.blk; s->rq =3D NULL; diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index f7345b0511..7877ae67ae 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -56,6 +56,7 @@ typedef struct VirtIOBlock { bool dataplane_started; struct VirtIOBlockDataPlane *dataplane; uint64_t host_features; + size_t config_size; } VirtIOBlock; =20 typedef struct VirtIOBlockReq { --=20 2.20.1