Re: [PATCH] drm/xe/debugfs: Don't expose dgfx residencies attributes on VF

[Gustavo Sousa <gustavo.sousa@intel.com>]

Quoting Gustavo Sousa (2025-09-05 15:56:13-03:00)
>Quoting Michal Wajdeczko (2025-09-05 15:40:14-03:00)
>>
>>
>>On 9/5/2025 8:22 PM, Gustavo Sousa wrote:
>>> Quoting Michal Wajdeczko (2025-09-05 14:36:25-03:00)
>>>> In addition of checking if we are running on the BATTLEMAGE,
>>>> we should also check for not being a VF driver, as VFs can't
>>>> access necessary registers, and doing so leads to:
>>>>
>>>> | .. [drm] GT0: VF is trying to read an inaccessible register 0x35b004+0x0
>>>> | RIP: 0010:xe_gt_sriov_vf_read32+0x5e2/0x8a0 [xe]
>>>> | Call Trace:
>>>> |  xe_mmio_read32+0x110/0x280 [xe]
>>>> |  read_residency_counter+0x42/0xd0 [xe]
>>>> |  dgfx_pkg_residencies_show+0x115/0x190 [xe]
>>>> | .. [drm] Package G2 counter failed to read, ret -19
>>>>
>>>> or
>>>>
>>>> | .. [drm] GT0: VF is trying to read an inaccessible register 0x35b004+0x0
>>>> | RIP: 0010:xe_gt_sriov_vf_read32+0x5e2/0x8a0 [xe]
>>>> | Call Trace:
>>>> |  xe_mmio_read32+0x110/0x280 [xe]
>>>> |  read_residency_counter+0x42/0xd0 [xe]
>>>> |  dgfx_pcie_link_residencies_show+0xe7/0x160 [xe]
>>>> | .. [drm] PCIE LINK L0 RESIDENCY counter failed to read, ret -19
>>>>
>>>> Similarly, there is no point to expose inject_csc_hw_error on VFs,
>>>> as HW errors support is already disabled for VFs.
>>>>
>>>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
>>>> Cc: Soham Purkait <soham.purkait@intel.com>
>>>> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
>>>> Cc: Riana Tauro <riana.tauro@intel.com>
>>> 
>>> I posted a very similar patch[1] ~1 month ago.
>>
>>oops
>
>But I think we can go ahead with this one, since it also covers skipping
>inject_csc_hw_error.
>
>>
>>> 
>>> There was a spec-related question from Rodrigo, for which I could not
>>> find the answer.
>>
>>I guess the answer in indirect - there is only small set of registers
>>that VFs can read directly, and above one 0x35b004 is not on this list.
>>
>>Bspec: 53221
>
>Ah, thanks!

With the Bspec reference above,

Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>

>
>--
>Gustavo Sousa
>
>>
>>> 
>>> [1] https://lore.kernel.org/all/20250729-skip-residency-debugfs-for-vfs-v1-1-3c5edec08c8b@intel.com/
>>> 
>>> --
>>> Gustavo Sousa
>>> 
>>>> ---
>>>> drivers/gpu/drm/xe/xe_debugfs.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
>>>> index 4b71570529a6..8be8304cb05c 100644
>>>> --- a/drivers/gpu/drm/xe/xe_debugfs.c
>>>> +++ b/drivers/gpu/drm/xe/xe_debugfs.c
>>>> @@ -346,7 +346,7 @@ void xe_debugfs_register(struct xe_device *xe)
>>>>                                  ARRAY_SIZE(debugfs_list),
>>>>                                  root, minor);
>>>>
>>>> -        if (xe->info.platform == XE_BATTLEMAGE) {
>>>> +        if (xe->info.platform == XE_BATTLEMAGE && !IS_SRIOV_VF(xe)) {
>>>>                 drm_debugfs_create_files(debugfs_residencies,
>>>>                                          ARRAY_SIZE(debugfs_residencies),
>>>>                                          root, minor);
>>>> -- 
>>>> 2.47.1
>>>>
>>