From patchwork Tue Jun 11 12:12:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenyu Zhang X-Patchwork-Id: 1946291 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=EvJnwfML; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) 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=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4Vz6z20rh7z20Pb for ; Tue, 11 Jun 2024 22:13:47 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sH0Mz-0004vC-Pr; Tue, 11 Jun 2024 08:12:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sH0My-0004uo-6C for qemu-devel@nongnu.org; Tue, 11 Jun 2024 08:12:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sH0Mw-0005L1-DT for qemu-devel@nongnu.org; Tue, 11 Jun 2024 08:12:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718107972; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=QcLixnG2KI5CWkQZHQ+4b3Ts+sRB/v3/rwwSGocDZfc=; b=EvJnwfML/3rXlrSWp1h18UQsLhaCHDNVQkpnAkWWyS/avrYnwoEoCcEHt6fH9fxn8ToeVX npH8z8JRgEU1fwmYthchZxZprtKQyBJAMv8N+DydYiz9p0PspOFmMth5TteIV4C4vITIx1 ieyskQPs1t1u6urNPCImFecVC0ZnnoY= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-393-5Q81PoYPNcm2CM0ReeZcxg-1; Tue, 11 Jun 2024 08:12:51 -0400 X-MC-Unique: 5Q81PoYPNcm2CM0ReeZcxg-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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 mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2FB491956089; Tue, 11 Jun 2024 12:12:49 +0000 (UTC) Received: from virt-mtsnow-02.lab.eng.rdu2.redhat.com (virt-mtsnow-02.lab.eng.rdu2.redhat.com [10.8.1.195]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 773B7300021B; Tue, 11 Jun 2024 12:12:46 +0000 (UTC) From: Zhenyu Zhang To: qemu-arm@nongnu.org Cc: zhenyzha@redhat.com, qemu-devel@nongnu.org, peter.maydell@linaro.org, robin.murphy@arm.com, Jonathan.Cameron@huawei.com, gshan@redhat.com, eauger@redhat.com, sebott@redhat.com, cohuck@redhat.com, ddutile@redhat.com, shahuang@redhat.com Subject: [PATCH v2] hw/arm/virt: Avoid unexpected warning from Linux guest on host with Fujitsu CPUs Date: Tue, 11 Jun 2024 08:12:22 -0400 Message-ID: <20240611121222.305185-1-zhenyzha@redhat.com> MIME-Version: 1.0\nContent-Type: text/plain; charset=UTF-8\nContent-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=zhenyzha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 46 X-Spam_score: 4.6 X-Spam_bar: ++++ X-Spam_report: (4.6 / 5.0 requ) BAYES_00=-1.9, BOGUS_MIME_VERSION=3.499, DKIMWL_WL_HIGH=-0.141, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Multiple warning messages and corresponding backtraces are observed when Linux guest is booted on the host with Fujitsu CPUs. One of them is shown as below. [ 0.032443] ------------[ cut here ]------------ [ 0.032446] uart-pl011 9000000.pl011: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (128 < 256) [ 0.032454] WARNING: CPU: 0 PID: 1 at arch/arm64/mm/dma-mapping.c:54 arch_setup_dma_ops+0xbc/0xcc [ 0.032470] Modules linked in: [ 0.032475] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-452.el9.aarch64 [ 0.032481] Hardware name: linux,dummy-virt (DT) [ 0.032484] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.032490] pc : arch_setup_dma_ops+0xbc/0xcc [ 0.032496] lr : arch_setup_dma_ops+0xbc/0xcc [ 0.032501] sp : ffff80008003b860 [ 0.032503] x29: ffff80008003b860 x28: 0000000000000000 x27: ffffaae4b949049c [ 0.032510] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 0.032517] x23: 0000000000000100 x22: 0000000000000000 x21: 0000000000000000 [ 0.032523] x20: 0000000100000000 x19: ffff2f06c02ea400 x18: ffffffffffffffff [ 0.032529] x17: 00000000208a5f76 x16: 000000006589dbcb x15: ffffaae4ba071c89 [ 0.032535] x14: 0000000000000000 x13: ffffaae4ba071c84 x12: 455f525443206e61 [ 0.032541] x11: 68742072656c6c61 x10: 0000000000000029 x9 : ffffaae4b7d21da4 [ 0.032547] x8 : 0000000000000029 x7 : 4c414e494d5f414d x6 : 0000000000000029 [ 0.032553] x5 : 000000000000000f x4 : ffffaae4b9617a00 x3 : 0000000000000001 [ 0.032558] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff2f06c029be40 [ 0.032564] Call trace: [ 0.032566] arch_setup_dma_ops+0xbc/0xcc [ 0.032572] of_dma_configure_id+0x138/0x300 [ 0.032591] amba_dma_configure+0x34/0xc0 [ 0.032600] really_probe+0x78/0x3dc [ 0.032614] __driver_probe_device+0x108/0x160 [ 0.032619] driver_probe_device+0x44/0x114 [ 0.032624] __device_attach_driver+0xb8/0x14c [ 0.032629] bus_for_each_drv+0x88/0xe4 [ 0.032634] __device_attach+0xb0/0x1e0 [ 0.032638] device_initial_probe+0x18/0x20 [ 0.032643] bus_probe_device+0xa8/0xb0 [ 0.032648] device_add+0x4b4/0x6c0 [ 0.032652] amba_device_try_add.part.0+0x48/0x360 [ 0.032657] amba_device_add+0x104/0x144 [ 0.032662] of_amba_device_create.isra.0+0x100/0x1c4 [ 0.032666] of_platform_bus_create+0x294/0x35c [ 0.032669] of_platform_populate+0x5c/0x150 [ 0.032672] of_platform_default_populate_init+0xd0/0xec [ 0.032697] do_one_initcall+0x4c/0x2e0 [ 0.032701] do_initcalls+0x100/0x13c [ 0.032707] kernel_init_freeable+0x1c8/0x21c [ 0.032712] kernel_init+0x28/0x140 [ 0.032731] ret_from_fork+0x10/0x20 [ 0.032735] ---[ end trace 0000000000000000 ]--- In Linux, a check is applied to every device which is exposed through device-tree node. The warning message is raised when the device isn't DMA coherent and the cache line size is larger than ARCH_DMA_MINALIGN (128 bytes). The cache line is sorted from CTR_EL0[CWG], which corresponds to 256 bytes on the guest CPUs. The DMA coherent capability is claimed through 'dma-coherent' property in their device-tree nodes or parent nodes. Fix the issue by adding 'dma-coherent' property to the device-tree root node, meaning all devices are capable of DMA coherent by default. Signed-off-by: Zhenyu Zhang --- hw/arm/virt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 3c93c0c0a6..0680b792bc 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -270,6 +270,7 @@ static void create_fdt(VirtMachineState *vms) qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2); qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2); qemu_fdt_setprop_string(fdt, "/", "model", "linux,dummy-virt"); + qemu_fdt_setprop(fdt, "/", "dma-coherent", NULL, 0); /* /chosen must exist for load_dtb to fill in necessary properties later */ qemu_fdt_add_subnode(fdt, "/chosen");