[PATCH 1/3] drm/amdkfd: Define config HSA_AMD_P2P to support peer-to-peer

[Felix Kuehling]

On 2022-06-03 06:52, Ramesh Errabolu wrote:
> Extend current kernel config requirements of amdgpu by adding config
> HSA_AMD_P2P. Enabling HSA_AMD_P2P is REQUIRED to support peer-to-peer
> communication between AMD GPU devices over PCIe bus
>
> Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu at amd.com>

This patch is

Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>


> ---
>   drivers/gpu/drm/amd/amdkfd/Kconfig | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/Kconfig b/drivers/gpu/drm/amd/amdkfd/Kconfig
> index 8cc0a76ddf9f..93bd4eda0d94 100644
> --- a/drivers/gpu/drm/amd/amdkfd/Kconfig
> +++ b/drivers/gpu/drm/amd/amdkfd/Kconfig
> @@ -25,3 +25,17 @@ config HSA_AMD_SVM
>   	  preemptions and one based on page faults. To enable page fault
>   	  based memory management on most GFXv9 GPUs, set the module
>   	  parameter amdgpu.noretry=0.
> +
> +config HSA_AMD_P2P
> +	bool "HSA kernel driver support for peer-to-peer for AMD GPU devices"
> +	depends on HSA_AMD && PCI_P2PDMA && DMABUF_MOVE_NOTIFY
> +	help
> +	  Enable peer-to-peer (P2P) communication between AMD GPUs over
> +	  the PCIe bus. This can improve performance of multi-GPU compute
> +	  applications and libraries by enabling GPUs to access data directly
> +	  in peer GPUs' memory without intermediate copies in system memory.
> +
> +	  This P2P feature is only enabled on compatible chipsets, and between
> +	  GPUs with large memory BARs that expose the entire VRAM in PCIe bus
> +	  address space within the physical address limits of the GPUs.
> +