From patchwork Thu Jun 6 10:47:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenyu Zhang X-Patchwork-Id: 13688288 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.gnu.org (lists.gnu.org [209.51.188.17]) (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 0E410C27C52 for ; Thu, 6 Jun 2024 10:49:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sFAge-00028X-Ad; Thu, 06 Jun 2024 06:49:40 -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 1sFAgd-00028A-K1 for qemu-devel@nongnu.org; Thu, 06 Jun 2024 06:49:39 -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 1sFAga-00050W-Sb for qemu-devel@nongnu.org; Thu, 06 Jun 2024 06:49:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717670976; 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=CMws9XKKNqLHNAZjVr6cRVE4P3G9ltVNEHGDPxoP3g8=; b=Vn/UfnMErG6lWaDgk8lSiGUOyycH3/F9QtLBoY8P2qhiIKDYZ+0511vbvDMFc6pZsYFHTn fPKVvdqKiFJGXveWb00YJaHJETgt6Iiqr7tXxv+Jb+LFPO+fh47Nr+auwnJAMDtbITBtPA JqwbKXkogZWHWLAYMOQ+vdqtzG6nHRY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-649-4AvQoy8VMzGc7_gmBNiX9w-1; Thu, 06 Jun 2024 06:48:13 -0400 X-MC-Unique: 4AvQoy8VMzGc7_gmBNiX9w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (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 417BE85A588; Thu, 6 Jun 2024 10:48:13 +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 smtp.corp.redhat.com (Postfix) with ESMTPS id E32652166B00; Thu, 6 Jun 2024 10:48:12 +0000 (UTC) From: Zhenyu Zhang To: qemu-arm@nongnu.org Cc: zhenyzha@redhat.com, qemu-devel@nongnu.org, gshan@redhat.com, eauger@redhat.com, sebott@redhat.com, peter.maydell@linaro.org, cohuck@redhat.com, ddutile@redhat.com, shahuang@redhat.com Subject: [PATCH RFC] hw/arm/virt: Avoid unexpected warning from Linux guest on host with Fujitsu CPUs Date: Thu, 6 Jun 2024 06:47:45 -0400 Message-ID: <20240606104745.291330-1-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 10.11.54.6 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: 14 X-Spam_score: 1.4 X-Spam_bar: + X-Spam_report: (1.4 / 5.0 requ) BAYES_00=-1.9, BOGUS_MIME_VERSION=3.496, DKIMWL_WL_HIGH=-0.001, 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, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.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 #1 [ 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' in their device-tree nodes. I don't see those devices need to be DMA incoherent necessarily and those devices will do DMA operations in practice. So lets add 'dma-coherent' property to their device-tree nodes to avoid the unexpected warnings in the Linux guest. Signed-off-by: Zhenyu Zhang --- hw/arm/boot.c | 1 + hw/arm/virt.c | 4 ++++ hw/core/sysbus-fdt.c | 1 + 3 files changed, 6 insertions(+) diff --git a/hw/arm/boot.c b/hw/arm/boot.c index d480a7da02..cdf99966e6 100644 --- a/hw/arm/boot.c +++ b/hw/arm/boot.c @@ -509,6 +509,7 @@ static void fdt_add_psci_node(void *fdt) qemu_fdt_setprop_cell(fdt, "/psci", "cpu_off", cpu_off_fn); qemu_fdt_setprop_cell(fdt, "/psci", "cpu_on", cpu_on_fn); qemu_fdt_setprop_cell(fdt, "/psci", "migrate", migrate_fn); + qemu_fdt_setprop(fdt, "/psci", "dma-coherent", NULL, 0); } int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo, diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 3c93c0c0a6..d3e5f512e2 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -652,6 +652,7 @@ static void fdt_add_pmu_nodes(const VirtMachineState *vms) qemu_fdt_setprop_cells(ms->fdt, "/pmu", "interrupts", GIC_FDT_IRQ_TYPE_PPI, INTID_TO_PPI(VIRTUAL_PMU_IRQ), irqflags); + qemu_fdt_setprop(ms->fdt, "/pmu", "dma-coherent", NULL, 0); } } @@ -936,6 +937,7 @@ static void create_uart(const VirtMachineState *vms, int uart, vms->clock_phandle, vms->clock_phandle); qemu_fdt_setprop(ms->fdt, nodename, "clock-names", clocknames, sizeof(clocknames)); + qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0); if (uart == VIRT_UART) { qemu_fdt_setprop_string(ms->fdt, "/chosen", "stdout-path", nodename); @@ -972,6 +974,7 @@ static void create_rtc(const VirtMachineState *vms) GIC_FDT_IRQ_FLAGS_LEVEL_HI); qemu_fdt_setprop_cell(ms->fdt, nodename, "clocks", vms->clock_phandle); qemu_fdt_setprop_string(ms->fdt, nodename, "clock-names", "apb_pclk"); + qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0); g_free(nodename); } @@ -1077,6 +1080,7 @@ static void create_gpio_devices(const VirtMachineState *vms, int gpio, qemu_fdt_setprop_cell(ms->fdt, nodename, "clocks", vms->clock_phandle); qemu_fdt_setprop_string(ms->fdt, nodename, "clock-names", "apb_pclk"); qemu_fdt_setprop_cell(ms->fdt, nodename, "phandle", phandle); + qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0); if (gpio != VIRT_GPIO) { /* Mark as not usable by the normal world */ diff --git a/hw/core/sysbus-fdt.c b/hw/core/sysbus-fdt.c index eebcd28f9a..da47071a95 100644 --- a/hw/core/sysbus-fdt.c +++ b/hw/core/sysbus-fdt.c @@ -554,6 +554,7 @@ void platform_bus_add_all_fdt_nodes(void *fdt, const char *intc, hwaddr addr, qemu_fdt_setprop_cells(fdt, node, "ranges", 0, addr >> 32, addr, bus_size); qemu_fdt_setprop_phandle(fdt, node, "interrupt-parent", intc); + qemu_fdt_setprop(fdt, node, "dma-coherent", NULL, 0); dev = qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE); pbus = PLATFORM_BUS_DEVICE(dev);