Re: [PATCH 03/15] dma-buf & drm/amdgpu: remove dma_resv workaround

["Christian König" <christian.koenig@amd.com>]

Hi Zack,

Am 20.04.22 um 05:56 schrieb Zack Rusin:
> On Thu, 2022-04-07 at 10:59 +0200, Christian König wrote:
>> Rework the internals of the dma_resv object to allow adding more than
>> one
>> write fence and remember for each fence what purpose it had.
>>
>> This allows removing the workaround from amdgpu which used a container
>> for
>> this instead.
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Cc: amd-gfx@lists.freedesktop.org
>
> afaict this change broke vmwgfx which now kernel oops right after boot.
> I haven't had the time to look into it yet, so I'm not sure what's the
> problem. I'll look at this tomorrow, but just in case you have some
> clues, the backtrace follows:

that's a known issue and should already be fixed with:

commit d72dcbe9fce505228dae43bef9da8f2b707d1b3d
Author: Christian König <christian.koenig@amd.com>
Date:   Mon Apr 11 15:21:59 2022 +0200

     drm/ttm: fix logic inversion in ttm_eu_reserve_buffers

     That should have been max, not min.

     Signed-off-by: Christian König <christian.koenig@amd.com>
     Fixes: c8d4c18bfbc4 ("dma-buf/drivers: make reserving a shared slot 
mandatory v4")
     Reviewed-by: Matthew Auld <matthew.auld@intel.com>
     Link: 
https://patchwork.freedesktop.org/patch/msgid/20220411134537.2854-1-christian.koenig@amd.com


Just a stupid logic inversion. Sorry for the noise.

Regards,
Christian.

>
>   ------------[ cut here ]------------
>   kernel BUG at drivers/dma-buf/dma-resv.c:306!
>   invalid opcode: 0000 [#1] PREEMPT SMP PTI
>   CPU: 1 PID: 1608 Comm: gnome-shell Not tainted 5.18.0-rc1-vmwgfx #18
>   Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop
> Reference Platform, BIOS 6.00 11/12/2020
>   RIP: 0010:dma_resv_add_fence+0x2ed/0x300
>   Code: ff ff be 01 00 00 00 e8 31 7d d9 ff e9 80 fd ff ff be 03 00 00
> 00 e8 22 7d d9 ff e9 ee fe ff ff 0f 1f 44 00 00 e9 bc fe ff ff <0f> 0b
> e8 4c cc 45 00 66 6>
>   RSP: 0018:ffffa1e6846c3ab0 EFLAGS: 00010246
>   RAX: 0000000000000000 RBX: ffff94c5c5507138 RCX: 902bc24e7b7c70ae
>   RDX: 902bc24e7b7c70ae RSI: ffffffffaaf7f437 RDI: ffffffffaaffde66
>   RBP: ffffa1e6846c3b08 R08: 0000000000000000 R09: 0000000000000001
>   R10: 0000000000000004 R11: 0000000000000000 R12: ffff94c5cba90578
>   R13: 0000000000000000 R14: ffff94c5cba8bc00 R15: 0000000000000000
>   FS:  00007f9a17c6e600(0000) GS:ffff94c6f9e40000(0000)
> knlGS:0000000000000000
>   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>   CR2: 00007f9a14113000 CR3: 000000000144c003 CR4: 00000000003706e0
>   Call Trace:
>    <TASK>
>    ttm_eu_fence_buffer_objects+0x54/0x110 [ttm]
>    vmw_execbuf_process+0xcae/0x12a0 [vmwgfx]
>    ? vmw_execbuf_release_pinned_bo+0x60/0x60 [vmwgfx]
>    vmw_execbuf_ioctl+0xfb/0x160 [vmwgfx]
>    ? vmw_execbuf_release_pinned_bo+0x60/0x60 [vmwgfx]
>    drm_ioctl_kernel+0xba/0x150 [drm]
>    ? __might_fault+0x77/0x80
>    drm_ioctl+0x247/0x460 [drm]
>    ? vmw_execbuf_release_pinned_bo+0x60/0x60 [vmwgfx]
>    ? find_held_lock+0x31/0x90
>    ? __fget_files+0xc5/0x190
>    ? __this_cpu_preempt_check+0x13/0x20
>    ? lock_release+0x142/0x2f0
>    ? drm_ioctl_kernel+0x150/0x150 [drm]
>    vmw_generic_ioctl+0xa3/0x110 [vmwgfx]
>    vmw_unlocked_ioctl+0x15/0x20 [vmwgfx]
>    __x64_sys_ioctl+0x91/0xc0
>    do_syscall_64+0x3b/0x90
>    entry_SYSCALL_64_after_hwframe+0x44/0xae
>   RIP: 0033:0x7f9a1af1aaff
>   Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48
> 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89
> c0 3d 00 f0 ff ff 7>
>   RSP: 002b:00007ffd833696c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
>   RAX: ffffffffffffffda RBX: 00007ffd83369780 RCX: 00007f9a1af1aaff
>   RDX: 00007ffd83369780 RSI: 000000004028644c RDI: 000000000000000d
>   RBP: 000000004028644c R08: 0000000000001248 R09: 00007ffd83369808
>   R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffd83369808
>   R13: 000000000000000d R14: 000055719cb629c0 R15: 00007ffd83369808
>    </TASK>
>   Modules linked in: overlay snd_ens1371 intel_rapl_msr snd_ac97_codec
> intel_rapl_common ac97_bus vsock_loopback
> vmw_vsock_virtio_transport_common vmw_vsock_vmci>
>   ---[ end trace 0000000000000000 ]---
>
> z