From patchwork Mon Nov 6 17:12:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mikulas Patocka X-Patchwork-Id: 13447200 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B7719C4332F for ; Mon, 6 Nov 2023 17:12:54 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.628232.979455 (Exim 4.92) (envelope-from ) id 1r039U-0002FQ-F5; Mon, 06 Nov 2023 17:12:40 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 628232.979455; Mon, 06 Nov 2023 17:12:40 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1r039U-0002FH-Bn; Mon, 06 Nov 2023 17:12:40 +0000 Received: by outflank-mailman (input) for mailman id 628232; Mon, 06 Nov 2023 17:12:38 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1r039S-0002En-G0 for xen-devel@lists.xenproject.org; Mon, 06 Nov 2023 17:12:38 +0000 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id adebd26b-7cc7-11ee-9b0e-b553b5be7939; Mon, 06 Nov 2023 18:12:36 +0100 (CET) Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-632-_45CrAGuNjOuxKLbB7FT_Q-1; Mon, 06 Nov 2023 12:12:31 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 674ED3821568; Mon, 6 Nov 2023 17:12:30 +0000 (UTC) Received: from file1-rdu.file-001.prod.rdu2.dc.redhat.com (unknown [10.11.5.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 47C5D1121308; Mon, 6 Nov 2023 17:12:30 +0000 (UTC) Received: by file1-rdu.file-001.prod.rdu2.dc.redhat.com (Postfix, from userid 12668) id 3227530C72A7; Mon, 6 Nov 2023 17:12:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by file1-rdu.file-001.prod.rdu2.dc.redhat.com (Postfix) with ESMTP id 2E33F3FD16; Mon, 6 Nov 2023 18:12:30 +0100 (CET) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: adebd26b-7cc7-11ee-9b0e-b553b5be7939 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699290755; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=xtsXGyrCZBmUJfCxzrPKMMdVxxHur1sL8JecsuLgwa0=; b=Y+0xfMr2o5tCEnJaHnfqd7QUVxuT1ZZgxZs+imYKxly0YcZ/DEkMftE2YZBB7d0m3kIAZ/ S8Pfphv0I1F7+uesArUFqzAuOaUh7tDy4ZR8RlcdyjQHab+0zecKpDpdK8Eia1QhtST6Md wWpQ9XED4ohq9YgBOEgLsuISksliftA= X-MC-Unique: _45CrAGuNjOuxKLbB7FT_Q-1 Date: Mon, 6 Nov 2023 18:12:30 +0100 (CET) From: Mikulas Patocka To: Mike Snitzer cc: Keith Busch , Christoph Hellwig , Juergen Gross , Stefano Stabellini , xen-devel@lists.xenproject.org, iommu@lists.linux.dev, Marek Marczykowski-G'orecki , Jens Axboe , Sagi Grimberg , Jan Kara , Vlastimil Babka , Andrew Morton , Matthew Wilcox , Michal Hocko , stable@vger.kernel.org, regressions@lists.linux.dev, Alasdair Kergon , dm-devel@lists.linux.dev, linux-mm@kvack.org Subject: [PATCH v2] swiotlb-xen: provide the "max_mapping_size" method In-Reply-To: Message-ID: <151bef41-e817-aea9-675-a35fdac4ed@redhat.com> References: <3cb4133c-b6db-9187-a678-11ed8c9456e@redhat.com> <11a9886d-316c-edcd-d6da-24ad0b9a2b4@redhat.com> <20231106071008.GB17022@lst.de> <928b5df7-fada-cf2f-6f6a-257a84547c3@redhat.com> MIME-Version: 1.0 Content-ID: <478c056-3a19-eb50-34da-911cf13fc558@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 From: Keith Busch There's a bug that when using the XEN hypervisor with bios with large multi-page bio vectors on NVMe, the kernel deadlocks [1]. The deadlocks are caused by inability to map a large bio vector - dma_map_sgtable always returns an error, this gets propagated to the block layer as BLK_STS_RESOURCE and the block layer retries the request indefinitely. XEN uses the swiotlb framework to map discontiguous pages into contiguous runs that are submitted to the PCIe device. The swiotlb framework has a limitation on the length of a mapping - this needs to be announced with the max_mapping_size method to make sure that the hardware drivers do not create larger mappings. Without max_mapping_size, the NVMe block driver would create large mappings that overrun the maximum mapping size. Reported-by: Marek Marczykowski-Górecki Link: https://lore.kernel.org/stable/ZTNH0qtmint%2FzLJZ@mail-itl/ [1] Tested-by: Marek Marczykowski-Górecki Suggested-by: Christoph Hellwig Cc: stable@vger.kernel.org Signed-off-by: Keith Busch Signed-off-by: Mikulas Patocka Acked-by: Stefano Stabellini Reviewed-by: Christoph Hellwig --- drivers/xen/swiotlb-xen.c | 1 + 1 file changed, 1 insertion(+) Index: linux-stable/drivers/xen/swiotlb-xen.c =================================================================== --- linux-stable.orig/drivers/xen/swiotlb-xen.c 2023-11-03 17:57:18.000000000 +0100 +++ linux-stable/drivers/xen/swiotlb-xen.c 2023-11-06 15:30:59.000000000 +0100 @@ -405,4 +405,5 @@ const struct dma_map_ops xen_swiotlb_dma .get_sgtable = dma_common_get_sgtable, .alloc_pages = dma_common_alloc_pages, .free_pages = dma_common_free_pages, + .max_mapping_size = swiotlb_max_mapping_size, };