From patchwork Tue Nov 29 16:06:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zetao X-Patchwork-Id: 13058717 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B140C433FE for ; Tue, 29 Nov 2022 15:18:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235819AbiK2PSy (ORCPT ); Tue, 29 Nov 2022 10:18:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235463AbiK2PSZ (ORCPT ); Tue, 29 Nov 2022 10:18:25 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53D0C52895; Tue, 29 Nov 2022 07:18:23 -0800 (PST) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NM5Yc6XbdzmWL6; Tue, 29 Nov 2022 23:17:40 +0800 (CST) Received: from huawei.com (10.67.175.21) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 29 Nov 2022 23:18:19 +0800 From: Li Zetao To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v2 2/5] virtio-mem: Fix probe failed when modprobe virtio_mem Date: Wed, 30 Nov 2022 00:06:12 +0800 Message-ID: <20221129160615.3343036-3-lizetao1@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221129160615.3343036-1-lizetao1@huawei.com> References: <20221128021005.232105-1-lizetao1@huawei.com> <20221129160615.3343036-1-lizetao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.175.21] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org When doing the following test steps, an error was found: step 1: modprobe virtio_mem succeeded # modprobe virtio_mem <-- OK step 2: fault injection in virtio_mem_init() # modprobe -r virtio_mem <-- OK # ... CPU: 0 PID: 1837 Comm: modprobe Not tainted 6.1.0-rc6-00285-g6a1e40c4b995-dirty Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: should_fail.cold+0x5/0x1f ... virtio_mem_init_hotplug+0x9ae/0xe57 [virtio_mem] virtio_mem_init.cold+0x327/0x339 [virtio_mem] virtio_mem_probe+0x48e/0x910 [virtio_mem] virtio_dev_probe+0x608/0xae0 ... virtio_mem virtio4: could not reserve device region virtio_mem: probe of virtio4 failed with error -16 step 3: modprobe virtio_mem failed # modprobe virtio_mem <-- failed virtio_mem: probe of virtio4 failed with error -16 The root cause of the problem is that the virtqueues are not stopped on the error handling path when virtio_mem_init() fails in virtio_mem_probe(), resulting in an error "-ENOENT" returned in the next modprobe call in setup_vq(). virtio_pci_modern_device uses virtqueues to send or receive message, and "queue_enable" records whether the queues are available. In vp_modern_find_vqs(), all queues will be selected and activated, but once queues are enabled there is no way to go back except reset. Fix it by reset virtio device on error handling path. After virtio_mem_init_vq() succeeded, all virtqueues should be stopped on error handling path. Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug") Signed-off-by: Li Zetao Reviewed-by: David Hildenbrand --- v1 -> v2: modify the description error of the test case in step 3 and modify the fixes tag information. drivers/virtio/virtio_mem.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 0c2892ec6817..c7f09c2ce982 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -2793,6 +2793,7 @@ static int virtio_mem_probe(struct virtio_device *vdev) return 0; out_del_vq: + virtio_reset_device(vdev); vdev->config->del_vqs(vdev); out_free_vm: kfree(vm);