Re: [PATCH] drm/amdkfd: dqm fence memory corruption

[Qu Huang]

On 2021/1/28 5:50, Felix Kuehling wrote:
> Am 2021-01-27 um 7:33 a.m. schrieb Qu Huang:
> > Amdgpu driver uses 4-byte data type as DQM fence memory,
> > and transmits GPU address of fence memory to microcode
> > through query status PM4 message. However, query status
> > PM4 message definition and microcode processing are all
> > processed according to 8 bytes. Fence memory only allocates
> > 4 bytes of memory, but microcode does write 8 bytes of memory,
> > so there is a memory corruption.
>
> Thank you for pointing out that discrepancy. That's a good catch!
>
> I'd prefer to fix this properly by making dqm->fence_addr a u64 pointer.
> We should probably also fix up the query_status and
> amdkfd_fence_wait_timeout function interfaces to use a 64 bit fence
> values everywhere to be consistent.
>
> Regards,
>    Felix
Hi Felix, Thanks for your advice, please check v2 at 
https://lore.kernel.org/patchwork/patch/1372584/
Thanks,
Qu.
> > Signed-off-by: Qu Huang <jinsdb@xxxxxxx>
> > ---
> >   drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> > index e686ce2..8b38d0c 100644
> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> > @@ -1161,7 +1161,7 @@ static int start_cpsch(struct device_queue_manager *dqm)
> >   	pr_debug("Allocating fence memory\n");
> >   
> >   	/* allocate fence memory on the gart */
> > -	retval = kfd_gtt_sa_allocate(dqm->dev, sizeof(*dqm->fence_addr),
> > +	retval = kfd_gtt_sa_allocate(dqm->dev, sizeof(uint64_t),
> >   					&dqm->fence_mem);
> >   
> >   	if (retval)