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> -----Original Message-----
> From: Kuehling, Felix <Felix.Kuehling@xxxxxxx>
> Sent: Friday, March 17, 2023 5:16 PM
> To: Sider, Graham <Graham.Sider@xxxxxxx>; Russell, Kent
> <Kent.Russell@xxxxxxx>; Mahfooz, Hamza <Hamza.Mahfooz@xxxxxxx>;
> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] drm/amdgpu: add print for iommu translation mode
>
> On 2023-03-17 16:04, Sider, Graham wrote:
> > [AMD Official Use Only - General]
> >
> >
> >
> >> -----Original Message-----
> >> From: Russell, Kent <Kent.Russell@xxxxxxx>
> >> Sent: Friday, March 17, 2023 3:58 PM
> >> To: Mahfooz, Hamza <Hamza.Mahfooz@xxxxxxx>; Sider, Graham
> >> <Graham.Sider@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> >> Cc: Kuehling, Felix <Felix.Kuehling@xxxxxxx>
> >> Subject: RE: [PATCH] drm/amdgpu: add print for iommu translation mode
> >>
> >> [AMD Official Use Only - General]
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of
> >>> Hamza Mahfooz
> >>> Sent: Friday, March 17, 2023 3:58 PM
> >>> To: Sider, Graham <Graham.Sider@xxxxxxx>;
> >>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> >>> Cc: Kuehling, Felix <Felix.Kuehling@xxxxxxx>
> >>> Subject: Re: [PATCH] drm/amdgpu: add print for iommu translation
> >>> mode
> >>>
> >>>
> >>> On 3/17/23 15:47, Graham Sider wrote:
> >>>> Add log to display whether RAM is direct vs DMA mapped.
> >>>>
> >>>> Signed-off-by: Graham Sider <Graham.Sider@xxxxxxx>
> >>> If this information is only useful for debugging purposes, please
> >>> use
> >>> drm_dbg() instead of pr_info().
> > It's useful for more than just debug I would say. Just a quick way to grep
> whether IOMMU is off/pt vs device isolation mode.
>
> I agree. The kernel log otherwise tells you the default IOMMU domain, but it
> may not match the domain actually used for the GPU. Without this message
> there is no easy way to tell from a kernel log. This will help with triaging issues
> from logs provided by external and internal users.
>
>
> >
> > Graham
> >
> >>>> ---
> >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 +++++-
> >>>> 1 file changed, 5 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >>>> index 8bba5e6872a1..8797a9523244 100644
> >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> >>>> @@ -3528,8 +3528,12 @@ static void
> >>> amdgpu_device_check_iommu_direct_map(struct amdgpu_device
> *adev)
> >>>> struct iommu_domain *domain;
> >>>>
> >>>> domain = iommu_get_domain_for_dev(adev->dev);
> >>>> - if (!domain || domain->type == IOMMU_DOMAIN_IDENTITY)
> >>>> + if (!domain || domain->type == IOMMU_DOMAIN_IDENTITY) {
> >>>> + pr_info("RAM is direct mapped to GPU (not traslated by
>
> Use dev_info. That way you can tell which GPU the message applies to in a
> multi-GPU system.
>
Good point - will do that. Thanks!
Graham
> Regards,
> Felix
>
>
> >> traslated -> translated
> >>
> > Thanks, my keyboard keeps skipping the on the 'n' key lately :( time for a
> clean.
> >
> > Graham
> >
> >> Kent
> >>> IOMMU)\n");
> >>>> adev->ram_is_direct_mapped = true;
> >>>> + } else {
> >>>> + pr_info("RAM is DMA mapped to GPU (translated by
> >>> IOMMU)\n");
> >>>> + }
> >>>> }
> >>>>
> >>>> static const struct attribute *amdgpu_dev_attributes[] = {
> >>> --
> >>> Hamza
