[PATCH v3] drm/xe/pf: Don't allow LMEM provisioning if LMTT isn't available on the device

[Michal Wajdeczko]

On 17.04.2025 20:18, Summers, Stuart wrote:
> On Thu, 2025-04-17 at 16:21 +0200, Piórkowski, Piotr wrote:
>> From: Piotr Piórkowski <piotr.piorkowski at intel.com>
>>
>> The LMEM provisioning is applicable only on platforms with LMTT.
>>
>> v2:
>>  - new commit description
>>  - use xe_gt_assert in xe_gt_sriov_pf_config_set_lmem instead return
>>    error,
>>  - disable pf_lmem_info if LMTT is not available
>> v3: fix condition in xe_gt_assert
>>
>> Signed-off-by: Piotr Piórkowski <piotr.piorkowski at intel.com>
>> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> ---
>>  drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c  | 6 ++++--
>>  drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c | 4 ++--
>>  2 files changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
>> b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
>> index 2420a548cacc..3556c41c041b 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
>> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
>> @@ -1520,6 +1520,8 @@ int xe_gt_sriov_pf_config_set_lmem(struct xe_gt
>> *gt, unsigned int vfid, u64 size
>>  {
>>         int err;
>>  
>> +       xe_gt_assert(gt, xe_device_has_lmtt(gt_to_xe(gt)));
>> +
>>         mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
>>         if (vfid)
>>                 err = pf_provision_vf_lmem(gt, vfid, size);
>> @@ -1629,7 +1631,7 @@ int xe_gt_sriov_pf_config_set_fair_lmem(struct
>> xe_gt *gt, unsigned int vfid,
>>         xe_gt_assert(gt, num_vfs);
>>         xe_gt_assert(gt, !xe_gt_is_media_type(gt));
>>  
>> -       if (!IS_DGFX(gt_to_xe(gt)))
>> +       if (!xe_device_has_lmtt(gt_to_xe(gt)))
>>                 return 0;
>>  
>>         mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
>> @@ -2163,7 +2165,7 @@ static int pf_validate_vf_config(struct xe_gt
>> *gt, unsigned int vfid)
>>         valid_all = valid_all && valid_ggtt;
>>         valid_any = valid_any || (valid_ggtt && is_primary);
>>  
>> -       if (IS_DGFX(xe)) {
>> +       if (xe_device_has_lmtt(xe)) {
> 
> I see a few other calls like pf_sanitize_vf_resources() and

from old offline discussion - there is/was a plan to reuse lmem_obj also
when we will not let to configure LMEM manually, not sure if that stands
still, though

> pf_validate_vf_config() 

it's touched in this patch right here ;)

> and pf_restore_vf_config_klv() and
> pf_get_ggtt_alignment() in this same file. Is there a reason not to
> just change all these at once?

if we want to allow the LMEM configuration only with LMTT then agree

then maybe we should drop new explicit assert in:

	xe_gt_sriov_pf_config_set_lmem

and instead replace legacy IS_DGFX in:

	pf_release_vf_config_lmem
	pf_provision_vf_lmem
	pf_release_vf_config

but let Piotr speak here

> 
> Also right now has_lmtt just calls IS_DGFX, and I confirmed this looks
> right from the specs, so at a high level:
> Reviewed-by: Stuart Summers <stuart.summers at intel.com>

I'll wait with my r-b until Piotr reply

> 
> Thanks,
> Stuart
> 
>>                 bool valid_lmem = pf_get_vf_config_lmem(primary_gt,
>> vfid);
>>  
>>                 valid_any = valid_any || (valid_lmem && is_primary);
>> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
>> b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
>> index 0fe47f41b63c..13970d5a2867 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
>> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
>> @@ -308,7 +308,7 @@ static void pf_add_config_attrs(struct xe_gt *gt,
>> struct dentry *parent, unsigne
>>         if (!xe_gt_is_media_type(gt)) {
>>                 debugfs_create_file_unsafe(vfid ? "ggtt_quota" :
>> "ggtt_spare",
>>                                            0644, parent, parent,
>> &ggtt_fops);
>> -               if (IS_DGFX(gt_to_xe(gt)))
>> +               if (xe_device_has_lmtt(gt_to_xe(gt)))
>>                         debugfs_create_file_unsafe(vfid ?
>> "lmem_quota" : "lmem_spare",
>>                                                    0644, parent,
>> parent, &lmem_fops);
>>         }
>> @@ -558,7 +558,7 @@ void xe_gt_sriov_pf_debugfs_register(struct xe_gt
>> *gt, struct dentry *root)
>>                 drm_debugfs_create_files(pf_ggtt_info,
>>                                          ARRAY_SIZE(pf_ggtt_info),
>>                                          pfdentry, minor);
>> -               if (IS_DGFX(gt_to_xe(gt)))
>> +               if (xe_device_has_lmtt(gt_to_xe(gt)))
>>                         drm_debugfs_create_files(pf_lmem_info,
>>                                                 
>> ARRAY_SIZE(pf_lmem_info),
>>                                                  pfdentry, minor);
>