From patchwork Wed Feb 13 01:48:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liu, Changpeng" X-Patchwork-Id: 10808995 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EB25A13B5 for ; Wed, 13 Feb 2019 01:31:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D57762BFD9 for ; Wed, 13 Feb 2019 01:31:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CA0882C13F; Wed, 13 Feb 2019 01:31:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 12A932C12B for ; Wed, 13 Feb 2019 01:31:44 +0000 (UTC) Received: from localhost ([127.0.0.1]:49007 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gtjOp-0003iU-VZ for patchwork-qemu-devel@patchwork.kernel.org; Tue, 12 Feb 2019 20:31:43 -0500 Received: from eggs.gnu.org ([209.51.188.92]:33127) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gtjOA-0003Q1-PW for qemu-devel@nongnu.org; Tue, 12 Feb 2019 20:31:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gtjO9-0003SW-Hf for qemu-devel@nongnu.org; Tue, 12 Feb 2019 20:31:02 -0500 Received: from mga03.intel.com ([134.134.136.65]:55974) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gtjO9-00038D-81 for qemu-devel@nongnu.org; Tue, 12 Feb 2019 20:31:01 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Feb 2019 17:30:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,364,1544515200"; d="scan'208";a="274605169" Received: from fedora.sh.intel.com ([10.67.114.176]) by orsmga004.jf.intel.com with ESMTP; 12 Feb 2019 17:30:43 -0800 From: Changpeng Liu To: qemu-devel@nongnu.org Date: Wed, 13 Feb 2019 09:48:57 +0800 Message-Id: <1550022537-27565-1-git-send-email-changpeng.liu@intel.com> X-Mailer: git-send-email 1.9.3 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.65 Subject: [Qemu-devel] [PATCH v4] virtio-blk: set correct config size for the host driver 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: ldoktor@redhat.com, mst@redhat.com, dgilbert@redhat.com, stefanha@redhat.com, changpeng.liu@intel.com, sgarzare@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Commit caa1ee43 "vhost-user-blk: add discard/write zeroes features support" added fields to struct virtio_blk_config. This changes the size of the config space and breaks migration from QEMU 3.1 and older: qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x10 read: 41 device: 1 cmask: ff wmask: 80 w1cmask:0 qemu-system-ppc64: Failed to load PCIDevice:config qemu-system-ppc64: Failed to load virtio-blk:virtio qemu-system-ppc64: error while loading state for instance 0x0 of device 'pci@800000020000000:01.0/virtio-blk' qemu-system-ppc64: load of migration failed: Invalid argument Since virtio-blk doesn't support the "discard" and "write zeroes" features, it shouldn't even expose the associated fields in the config space actually. Just include all fields up to num_queues to match QEMU 3.1 and older. Signed-off-by: Changpeng Liu Reviewed-by: Michael S. Tsirkin Reviewed-by: Greg Kurz Tested-by: Greg Kurz --- hw/block/virtio-blk.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 9a87b3b..6fce9c7 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -28,6 +28,10 @@ #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" +/* We don't support discard yet, hide associated config fields. */ +#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \ + max_discard_sectors) + static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, VirtIOBlockReq *req) { @@ -761,7 +765,8 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) blkcfg.alignment_offset = 0; blkcfg.wce = blk_enable_write_cache(s->blk); virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); - memcpy(config, &blkcfg, sizeof(struct virtio_blk_config)); + memcpy(config, &blkcfg, VIRTIO_BLK_CFG_SIZE); + QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg)); } static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) @@ -769,7 +774,8 @@ static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) VirtIOBlock *s = VIRTIO_BLK(vdev); struct virtio_blk_config blkcfg; - memcpy(&blkcfg, config, sizeof(blkcfg)); + memcpy(&blkcfg, config, VIRTIO_BLK_CFG_SIZE); + QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg)); aio_context_acquire(blk_get_aio_context(s->blk)); blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); @@ -952,8 +958,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) return; } - virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, - sizeof(struct virtio_blk_config)); + virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE); s->blk = conf->conf.blk; s->rq = NULL;