[PATCH] drm/amdgpu: avoid clearing freed bo with sdma in gpu reset
Zhou, Tiecheng
Tiecheng.Zhou at amd.com
Wed May 6 10:35:50 UTC 2020
[AMD Official Use Only - Internal Distribution Only]
Thanks, Christian,
Is this the fix that you are mentioning:
commit 1675c3a24d075d484377003789245f48c2114a0b
Author: Christian König <christian.koenig at amd.com>
Date: Fri Feb 21 15:10:31 2020 +0100
drm/amdgpu: stop disable the scheduler during HW fini
When we stop the HW for example for GPU reset we should not stop the
front-end scheduler. Otherwise we run into intermediate failures during
command submission.
The scheduler should only be stopped in very few cases:
1. We can't get the hardware working in ring or IB test after a GPU reset.
2. The KIQ scheduler is not used in the front-end and should be disabled during GPU reset.
3. In amdgpu_ring_fini() when the driver unloads.
Signed-off-by: Christian König <christian.koenig at amd.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Acked-by: Nirmoy Das <nirmoy.das at amd.com>
Test-by: Dennis Li <dennis.li at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Thanks
Tiecheng
-----Original Message-----
From: Christian König <ckoenig.leichtzumerken at gmail.com>
Sent: Wednesday, May 6, 2020 5:44 PM
To: Zhou, Tiecheng <Tiecheng.Zhou at amd.com>; amd-gfx at lists.freedesktop.org
Subject: Re: [PATCH] drm/amdgpu: avoid clearing freed bo with sdma in gpu reset
NAK, the fundamental problem was that we disabled the SDMA paging queue during reset:
> [ 885.694682] [drm] schedpage0 is not ready, skipping [ 885.694682]
> [drm] schedpage1 is not ready, skipping
This is fixed by now, so the problem should not happen any more.
Regards,
Christian.
Am 06.05.20 um 11:36 schrieb Tiecheng Zhou:
> WHY:
> For V320 passthrough and "modprobe amdgpu lockup_timeout=500", there
> will be kernel NULL pointer when using quark ~ BACO reset, for instance:
> hang_vm_compute0_bad_cs_dispatch.lua
> hang_vm_dma0_corrupted_header.lua
> etc.
> -----------------------------
> [ 884.792885] [drm:amdgpu_job_timedout [amdgpu]] *ERROR* ring
> comp_1.0.0 timeout, signaled seq=3, emitted seq=4 [ 884.793772]
> [drm:amdgpu_job_timedout [amdgpu]] *ERROR* Process information:
> process quark pid 16939 thread quark pid 16940 [ 884.859979] amdgpu:
> [powerplay] set virtualization GFX DPM policy success [ 884.861003]
> amdgpu: [powerplay] activate virtualization GFX DPM policy success [ 884.861065] amdgpu: [powerplay] set virtualization VCE DPM policy success [ 885.693554] [drm:amdgpu_cs_ioctl [amdgpu]] *ERROR* Failed to initialize parser -125!
> [ 885.694682] [drm] schedpage0 is not ready, skipping [ 885.694682]
> [drm] schedpage1 is not ready, skipping [ 885.694720]
> [drm:amdgpu_gem_va_ioctl [amdgpu]] *ERROR* Couldn't update BO_VA (-2)
> [ 885.695328] BUG: unable to handle kernel NULL pointer dereference
> at 0000000000000008 [ 885.695909] PGD 0 P4D 0 [ 885.696104] Oops:
> 0000 [#1] SMP PTI
> [ 885.696368] CPU: 2 PID: 16940 Comm: quark Tainted: G OE 4.19.52+ #6
> [ 885.696945] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> BIOS 1.10.2-1 04/01/2014 [ 885.697593] RIP:
> 0010:amdgpu_vm_sdma_commit+0x59/0x130 [amdgpu] ...
> [ 885.705042] Call Trace:
> [ 885.705251] ? amdgpu_vm_bo_update_mapping+0xdf/0xf0 [amdgpu] [
> 885.705696] ? amdgpu_vm_clear_freed+0xcc/0x1b0 [amdgpu] [
> 885.706112] ? amdgpu_gem_va_ioctl+0x4a1/0x510 [amdgpu] [ 885.706493]
> ? __radix_tree_delete+0x7e/0xa0 [ 885.706822] ?
> amdgpu_gem_va_map_flags+0x70/0x70 [amdgpu] [ 885.707220] ?
> drm_ioctl_kernel+0xaa/0xf0 [drm] [ 885.707568] ?
> amdgpu_gem_va_map_flags+0x70/0x70 [amdgpu] [ 885.707962] ?
> drm_ioctl_kernel+0xaa/0xf0 [drm] [ 885.708294] ?
> drm_ioctl+0x3a7/0x3f0 [drm] [ 885.708632] ?
> amdgpu_gem_va_map_flags+0x70/0x70 [amdgpu] [ 885.709032] ?
> unmap_region+0xd9/0x120 [ 885.709328] ? amdgpu_drm_ioctl+0x49/0x80
> [amdgpu] [ 885.709684] ? do_vfs_ioctl+0xa1/0x620 [ 885.709971] ?
> do_munmap+0x32e/0x430 [ 885.710232] ? ksys_ioctl+0x66/0x70 [
> 885.710513] ? __x64_sys_ioctl+0x16/0x20 [ 885.710806] ?
> do_syscall_64+0x55/0x100 [ 885.711092] ?
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
> ...
> [ 885.719408] ---[ end trace 7ee3180f42e9f572 ]--- [ 885.719766]
> RIP: 0010:amdgpu_vm_sdma_commit+0x59/0x130 [amdgpu] ...
> -----------------------------
>
> the NULL pointer (entity->rq == NULL in amdgpu_vm_sdma_commit()) as follows:
> 1. quark sends bad job that triggers job timeout; 2. guest KMD detects
> the job timeout and goes to gpu recovery, and it goes to
> ip_suspend for SDMA, and it sets sdma[].sched.ready to false; 3.
> quark sends UNMAP operation through amdgpu_gem_va_ioctl, and guest KMD goes
> through amdgpu_gem_va_update_vm and finally goes to amdgpu_vm_sdma_commit,
> it goes to amdgpu_job_submit to drm_sched_job_init 4.
> drm_sched_job_init fails at drm_sched_pick_best() since
> sdma[].sched.ready is set to false; in the meanwhile entity->rq
> becomes NULL; 5. quark sends other UNMAP operations through amdgpu_gem_va_ioctl, while this time
> there will be NULL pointer because entity->rq is NULL;
>
> the above sequence occurs only when "modprobe amdgpu lockup_timeout=500".
> it does not occur when lockup_timeout=10000 (default) because step 2.
> KMD detects job timeout will be sometime after quark sends UNMAP
> operations; i.e. quark UNMAP opeartions are finished before sdma ip suspend.
>
> HOW:
> here is to add mutex_lock to wait to avoid using sdma during gpu reset.
>
> Signed-off-by: Tiecheng Zhou <Tiecheng.Zhou at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index e205ecc75a21..018b88f3b6da 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -2047,6 +2047,8 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
> struct dma_fence *f = NULL;
> int r;
>
> + mutex_lock(&adev->lock_reset);
> +
> while (!list_empty(&vm->freed)) {
> mapping = list_first_entry(&vm->freed,
> struct amdgpu_bo_va_mapping, list); @@ -2062,6 +2064,7 @@ int
> amdgpu_vm_clear_freed(struct amdgpu_device *adev,
> amdgpu_vm_free_mapping(adev, vm, mapping, f);
> if (r) {
> dma_fence_put(f);
> + mutex_unlock(&adev->lock_reset);
> return r;
> }
> }
> @@ -2073,6 +2076,7 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
> dma_fence_put(f);
> }
>
> + mutex_unlock(&adev->lock_reset);
> return 0;
>
> }
More information about the amd-gfx
mailing list