From patchwork Tue Feb 12 15:19:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liu, Changpeng" X-Patchwork-Id: 1040638 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43zQz804MPz9sMl for ; Wed, 13 Feb 2019 02:08:52 +1100 (AEDT) Received: from localhost ([127.0.0.1]:40995 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gtZg1-0003xo-Tq for incoming@patchwork.ozlabs.org; Tue, 12 Feb 2019 10:08:49 -0500 Received: from eggs.gnu.org ([209.51.188.92]:41041) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gtZeE-0002zx-St for qemu-devel@nongnu.org; Tue, 12 Feb 2019 10:07:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gtZZL-00077I-KQ for qemu-devel@nongnu.org; Tue, 12 Feb 2019 10:01:56 -0500 Received: from mga17.intel.com ([192.55.52.151]:45376) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gtZZJ-0006jV-Mi for qemu-devel@nongnu.org; Tue, 12 Feb 2019 10:01:55 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Feb 2019 07:01:39 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,362,1544515200"; d="scan'208";a="132987563" Received: from fedora.sh.intel.com ([10.67.114.176]) by FMSMGA003.fm.intel.com with ESMTP; 12 Feb 2019 07:01:37 -0800 From: Changpeng Liu To: qemu-devel@nongnu.org Date: Tue, 12 Feb 2019 23:19:49 +0800 Message-Id: <1549984789-26997-1-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: 192.55.52.151 Subject: [Qemu-devel] [PATCH v3] 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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: Greg Kurz Tested-by: Greg Kurz --- hw/block/virtio-blk.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 9a87b3b..0ff5315 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 +765,9 @@ 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(struct virtio_blk_config)); + } static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) @@ -769,7 +775,8 @@ 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 +959,7 @@ 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;