From mboxrd@z Thu Jan 1 00:00:00 1970 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 4C82BC6FA8E for ; Sat, 25 Feb 2023 14:55:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229539AbjBYOz1 (ORCPT ); Sat, 25 Feb 2023 09:55:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbjBYOzZ (ORCPT ); Sat, 25 Feb 2023 09:55:25 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0AC112043 for ; Sat, 25 Feb 2023 06:55:22 -0800 (PST) Received: from [192.168.2.94] (unknown [109.252.117.89]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 417C96602FB5; Sat, 25 Feb 2023 14:55:20 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1677336921; bh=GPaYuR5Gy6chLlPOIU2JZ+7K9lpjG/p10DVFCLmE4vI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=MU5VbcbfC0QusKjWBXD79gAq7WtPDI4jCbUCX37OTtNCxYhAzQRsMdIYvIcZQnliX kIXwP//+YsQHnEJ/oLmaSftzRZ5vlhn0Sl6QZGQnajq7AWz9XL5xsNgzfzNW9E9hEc jHjE6VR8vCGBK70YCdNZB05GYvJhsWDy5DEoqGR+AfJnYZbfnw7Uo//Y2gbPd4Ty4+ r9RcLrILyKrWv0bNT/hMD3YY3ggV6IoYPPEULvRmjAqyhO/vuV3x36tTCTapKf+zuS sEc4uW51ZoPz/NIiC8l7jCYmwaAKotiLFVU+N8roRIoJIfYJ0kIQBG39ssTUoizeoK rzYbb8McmO57g== Message-ID: <4cb50dcb-b877-9602-3802-d651eea57b89@collabora.com> Date: Sat, 25 Feb 2023 17:55:16 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH] drm/virtio: Pass correct device to dma_sync_sgtable_for_device() Content-Language: en-US To: Oleksandr Tyshchenko , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Cc: Oleksandr Tyshchenko , David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Daniel Vetter , Juergen Gross , Stefano Stabellini References: <20230224153450.526222-1-olekstysh@gmail.com> From: Dmitry Osipenko In-Reply-To: <20230224153450.526222-1-olekstysh@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/24/23 18:34, Oleksandr Tyshchenko wrote: > From: Oleksandr Tyshchenko > > The "vdev->dev.parent" should be used instead of "vdev->dev" as a device > for which to perform the DMA operation in both > virtio_gpu_cmd_transfer_to_host_2d(3d). > > Because the virtio-gpu device "vdev->dev" doesn't really have DMA OPS > assigned to it, but parent (virtio-pci or virtio-mmio) device > "vdev->dev.parent" has. The more, the sgtable in question the code is > trying to sync here was mapped for the parent device (by using its DMA OPS) > previously at: > virtio_gpu_object_shmem_init()->drm_gem_shmem_get_pages_sgt()-> > dma_map_sgtable(), so should be synced here for the same parent device. > > Fixes: b5c9ed70d1a9 ("drm/virtio: Improve DMA API usage for shmem BOs") > Signed-off-by: Oleksandr Tyshchenko > --- > This patch fixes the following issue when running on top of Xen with > CONFIG_XEN_VIRTIO=y (patch was only tested in Xen environment (ARM64 guest) > w/ and w/o using Xen grants for virtio): > > [ 0.830235] [drm] pci: virtio-gpu-pci detected at 0000:00:03.0 > [ 0.832078] [drm] features: +virgl +edid -resource_blob -host_visible > [ 0.832084] [drm] features: -context_init > [ 0.837320] [drm] number of scanouts: 1 > [ 0.837460] [drm] number of cap sets: 2 > [ 0.904372] [drm] cap set 0: id 1, max-version 1, max-size 308 > [ 0.905399] [drm] cap set 1: id 2, max-version 2, max-size 696 > [ 0.907202] [drm] Initialized virtio_gpu 0.1.0 0 for 0000:00:03.0 on minor 0 > [ 0.927241] virtio-pci 0000:00:03.0: [drm] drm_plane_enable_fb_damage_clips() not called > [ 0.927279] Unable to handle kernel paging request at virtual address ffffffffc0053000 > [ 0.927284] Mem abort info: > [ 0.927286] ESR = 0x0000000096000144 > [ 0.927289] EC = 0x25: DABT (current EL), IL = 32 bits > [ 0.927293] SET = 0, FnV = 0 > [ 0.927295] EA = 0, S1PTW = 0 > [ 0.927298] FSC = 0x04: level 0 translation fault > [ 0.927301] Data abort info: > [ 0.927303] ISV = 0, ISS = 0x00000144 > [ 0.927305] CM = 1, WnR = 1 > [ 0.927308] swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000004127f000 > [ 0.927312] [ffffffffc0053000] pgd=0000000000000000, p4d=0000000000000000 > [ 0.927323] Internal error: Oops: 0000000096000144 [#1] PREEMPT SMP > [ 0.927329] Modules linked in: > [ 0.927336] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.2.0-rc4-yocto-standard #1 > [ 0.927343] Hardware name: XENVM-4.18 (DT) > [ 0.927346] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 0.927352] pc : dcache_clean_poc+0x20/0x38 > [ 0.927370] lr : arch_sync_dma_for_device+0x24/0x30 > [ 0.927379] sp : ffff80000972b3e0 > [ 0.927381] x29: ffff80000972b3e0 x28: ffff000001aa8a00 x27: 0000000000000000 > [ 0.927389] x26: 0000000000000000 x25: ffff000002815010 x24: 0000000000000000 > [ 0.927396] x23: ffff8000090f9078 x22: 0000000000000001 x21: 0000000000000002 > [ 0.927403] x20: ffff000002b6b580 x19: 8000000000053000 x18: ffffffffffffffff > [ 0.927410] x17: 0000000000000000 x16: 0000000000000000 x15: ffff80000963b94e > [ 0.927416] x14: 0000000000000001 x13: ffff80000963b93b x12: 64615f616d645f67 > [ 0.927423] x11: ffff800009513110 x10: 000000000000000a x9 : ffff80000972b360 > [ 0.927430] x8 : ffff8000095130c8 x7 : ffff80000972b150 x6 : 000000000000000c > [ 0.927436] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 000000000000003f > [ 0.927443] x2 : 0000000000000040 x1 : ffffffffc0067000 x0 : ffffffffc0053000 > [ 0.927450] Call trace: > [ 0.927452] dcache_clean_poc+0x20/0x38 > [ 0.927459] dma_direct_sync_sg_for_device+0x124/0x130 > [ 0.927466] dma_sync_sg_for_device+0x64/0xd0 > [ 0.927475] virtio_gpu_cmd_transfer_to_host_2d+0x10c/0x110 > [ 0.927483] virtio_gpu_primary_plane_update+0x340/0x3d0 > [ 0.927490] drm_atomic_helper_commit_planes+0xe8/0x20c > [ 0.927497] drm_atomic_helper_commit_tail+0x54/0xa0 > [ 0.927503] commit_tail+0x160/0x190 > [ 0.927507] drm_atomic_helper_commit+0x16c/0x180 > [ 0.927513] drm_atomic_commit+0xa8/0xe0 > [ 0.927521] drm_client_modeset_commit_atomic+0x200/0x260 > [ 0.927529] drm_client_modeset_commit_locked+0x5c/0x1a0 > [ 0.927536] drm_client_modeset_commit+0x30/0x60 > [ 0.927540] drm_fb_helper_set_par+0xc8/0x120 > [ 0.927548] fbcon_init+0x3b8/0x510 > [ 0.927557] visual_init+0xb4/0x104 > [ 0.927565] do_bind_con_driver.isra.0+0x1c4/0x394 > [ 0.927572] do_take_over_console+0x144/0x1fc > [ 0.927577] do_fbcon_takeover+0x6c/0xe4 > [ 0.927583] fbcon_fb_registered+0x1e4/0x1f0 > [ 0.927588] register_framebuffer+0x214/0x310 > [ 0.927592] __drm_fb_helper_initial_config_and_unlock+0x33c/0x540 > [ 0.927599] drm_fb_helper_initial_config+0x4c/0x60 > [ 0.927604] drm_fbdev_client_hotplug+0xc4/0x150 > [ 0.927609] drm_fbdev_generic_setup+0x90/0x154 > [ 0.927614] virtio_gpu_probe+0xc8/0x16c > [ 0.927621] virtio_dev_probe+0x19c/0x240 > [ 0.927629] really_probe+0xbc/0x2dc > [ 0.927637] __driver_probe_device+0x78/0xe0 > [ 0.927641] driver_probe_device+0xd8/0x160 > [ 0.927645] __driver_attach+0x94/0x19c > [ 0.927649] bus_for_each_dev+0x70/0xd0 > [ 0.927656] driver_attach+0x24/0x30 > [ 0.927660] bus_add_driver+0x154/0x20c > [ 0.927664] driver_register+0x78/0x130 > [ 0.927670] register_virtio_driver+0x24/0x3c > [ 0.927675] virtio_gpu_driver_init+0x18/0x24 > [ 0.927684] do_one_initcall+0x50/0x1d0 > [ 0.927691] kernel_init_freeable+0x210/0x27c > [ 0.927699] kernel_init+0x24/0x12c > [ 0.927707] ret_from_fork+0x10/0x20 > [ 0.927716] Code: d2800082 9ac32042 d1000443 8a230000 (d50b7a20) > [ 0.927721] ---[ end trace 0000000000000000 ]--- > [ 0.927728] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > [ 0.927732] SMP: stopping secondary CPUs > [ 0.927791] Kernel Offset: disabled > [ 0.927794] CPU features: 0x80000,41058100,0000421b > [ 0.927799] Memory Limit: none > [ 1.015063] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]--- > --- > --- > drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c > index a04a9b20896d..1778a2081fd6 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_vq.c > +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c > @@ -604,7 +604,7 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev, > bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev); > > if (virtio_gpu_is_shmem(bo) && use_dma_api) > - dma_sync_sgtable_for_device(&vgdev->vdev->dev, > + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, > bo->base.sgt, DMA_TO_DEVICE); > > cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); > @@ -1026,7 +1026,7 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev, > bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev); > > if (virtio_gpu_is_shmem(bo) && use_dma_api) > - dma_sync_sgtable_for_device(&vgdev->vdev->dev, > + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, > bo->base.sgt, DMA_TO_DEVICE); > > cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); Indeed, it's only the vgpu drm device that was moved to use the pci parent device. On x86 the vdev always has dma-ops, also virtio_has_dma_quirk=true for modern Qemu. So I didn't test this code path and apparently it's only testable on Xen, which is good to know. Reviewed-by: Dmitry Osipenko -- Best regards, Dmitry