(In reply to Christian König from comment #4)
> Created attachment 108165 [details] [review] [review]
> Possible fix
> 
> Ups! Forgotten to take the VM lock in radeon_gem_va_update_vm. Fix is
> attached.
> 
> Thanks for testing,
> Christian.

I don't know about Elemental as it's far harder to trigger, but first try with
valley produced -

[  156.617954] radeon 0000:01:00.0: GPU fault detected: 146 0x02e83504
[  156.617960] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_ADDR  
0x00010F17
[  156.617961] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_STATUS
0x08035004
[  156.617963] VM fault (0x04, vmid 4) at page 69399, read from VGT (53)