Re: [PATCH] drm/amdkfd: disable SVM for GC 10.1.3/4

[Felix Kuehling <felix.kuehling@amd.com>]

We need heavy-weight flushes not just for SVM. If this is broken it will 
affect ROCm either way.

Regards,
   Felix


On 2023-09-07 08:08, Lang Yu wrote:
> GC 10.1.3/4 have problems with TLB_FLUSH_HEAVYWEIGHT
> which is used by SVM in svm_range_unmap_from_gpus().
> This causes problems on GC 10.1.3/4.
>
> Signed-off-by: Lang Yu <Lang.Yu@amd.com>
> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 22 +++++++++++++++++-----
>   1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
> index 7d82c7da223a..dd3db3d88d59 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
> @@ -992,6 +992,22 @@ static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
>   /* Each VRAM page uses sizeof(struct page) on system memory */
>   #define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))
>   
> +static inline bool is_zone_device_needed(struct amdgpu_device *adev)
> +{
> +	/* Page migration works on gfx9 or newer */
> +	if (adev->ip_versions[GC_HWIP][0] < IP_VERSION(9, 0, 1))
> +		return false;
> +
> +	if (adev->ip_versions[GC_HWIP][0] == IP_VERSION(10, 1, 3) ||
> +	    adev->ip_versions[GC_HWIP][0] == IP_VERSION(10, 1, 4))
> +		return false;
> +
> +	if (adev->gmc.is_app_apu)
> +		return false;
> +
> +	return true;
> +}
> +
>   int kgd2kfd_init_zone_device(struct amdgpu_device *adev)
>   {
>   	struct amdgpu_kfd_dev *kfddev = &adev->kfd;
> @@ -1000,11 +1016,7 @@ int kgd2kfd_init_zone_device(struct amdgpu_device *adev)
>   	unsigned long size;
>   	void *r;
>   
> -	/* Page migration works on gfx9 or newer */
> -	if (adev->ip_versions[GC_HWIP][0] < IP_VERSION(9, 0, 1))
> -		return -EINVAL;
> -
> -	if (adev->gmc.is_app_apu)
> +	if (!is_zone_device_needed(adev))
>   		return 0;
>   
>   	pgmap = &kfddev->pgmap;