Am 18.07.19 um 22:46 schrieb Greathouse, Joseph: >> -----Original Message----- >> From: Christian König <ckoenig.leichtzumerken@xxxxxxxxx> >> Sent: Thursday, July 18, 2019 3:14 AM >> To: Kuehling, Felix <Felix.Kuehling@xxxxxxx>; Greathouse, Joseph >> <Joseph.Greathouse@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx >> Subject: Re: [PATCH v2] drm/amdgpu: Default disable GDS for compute >> VMIDs >> >> Am 17.07.19 um 22:09 schrieb Kuehling, Felix: >>> On 2019-07-17 14:23, Greathouse, Joseph wrote: >>>> The GDS and GWS blocks default to allowing all VMIDs to >>>> access all entries. Graphics VMIDs can handle setting >>>> these limits when the driver launches work. However, >>>> compute workloads under HWS control don't go through the >>>> kernel driver. Instead, HWS firmware should set these >>>> limits when a process is put into a VMID slot. >>>> >>>> Disable access to these devices by default by turning off >>>> all mask bits (for OA) and setting BASE=SIZE=0 (for GDS >>>> and GWS) for all compute VMIDs. If a process wants to use >>>> these resources, they can request this from the HWS >>>> firmware (when such capabilities are enabled). HWS will >>>> then handle setting the base and limit for the process when >>>> it is assigned to a VMID. >>>> >>>> This will also prevent user kernels from getting 'stuck' in >>>> GWS by accident if they write GWS-using code but HWS >>>> firmware is not set up to handle GWS reset. Until HWS is >>>> enabled to handle GWS properly, all GWS accesses will >>>> MEM_VIOL fault the kernel. >>>> >>>> v2: Move initialization outside of SRBM mutex >>>> >>>> Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d >>>> Signed-off-by: Joseph Greathouse <Joseph.Greathouse@xxxxxxx> >>> Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx> >> Might be a good idea to do this for all VMIDs during initialization and >> not just for the ones used for compute. >> >> But anyway patch is Reviewed-by: Christian König >> <christian.koenig@xxxxxxx>. > Hmm, good point. It looks like graphics jobs will eventually call through to emit_gds_switch() to set these when launching a job, but it may be worthwhile to set these to zero as a default. I didn't want to step on any toes on the graphics side without checking first. > > Do you have opinions on the most reasonable location to do this? early_init(), late_init()? The various gfx_v*_set_gds_init() might be a good place -- a quick test of setting all 16 VMIDs in gfx_v9_0_set_gds_init() appears to work fine on my Vega 20. With the exception of the GMC all hw initialization should be in hw_init. So set_gds_init might work, but is certainly the wrong place. I wouldn't mind renaming gfx_*_init_compute_vmid() into gfx_*_init_vmid() and setting reasonable defaults for both compute as well as gfx VMIDs. Christian. > > -Joe _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
