Re: [PATCH v9 4/4] drm/amdgpu: fix fence fallback timer expired error

["Lazar, Lijo" <lijo.lazar@amd.com>]

On 5/29/2025 3:32 PM, Samuel Zhang wrote:
> IH is not working after switching a new gpu index for the first time.
> 
> During VM resume, QEMU programming of VF MSIX table (register GFXMSIX_VECT0_ADDR_LO)
> may not work.The access could be blocked by nBIF protection as VF isn't in
> exclusive access mode. Exclusive access is enabled now, disable/enable MSIX
> so that QEMU reprograms MSIX table.
> 
> call amdgpu_restore_msix on resume to restore msix table.
> 
> Signed-off-by: Samuel Zhang <guoqing.zhang@amd.com>

Acked-by: Lijo Lazar <lijo.lazar@amd.com>

Thanks,
Lijo

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 +++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c    | 2 +-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h    | 1 +
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 0246a33b90af..f67bc9a52d53 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5051,6 +5051,13 @@ static inline int amdgpu_virt_resume(struct amdgpu_device *adev)
>  	int r;
>  	unsigned int prev_physical_node_id = adev->gmc.xgmi.physical_node_id;
>  
> +	/* During VM resume, QEMU programming of VF MSIX table (register GFXMSIX_VECT0_ADDR_LO)
> +	 * may not work. The access could be blocked by nBIF protection as VF isn't in
> +	 * exclusive access mode. Exclusive access is enabled now, disable/enable MSIX
> +	 * so that QEMU reprograms MSIX table.
> +	 */
> +	amdgpu_restore_msix(adev);
> +
>  	r = adev->gfxhub.funcs->get_xgmi_info(adev);
>  	if (r)
>  		return r;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> index 0e890f2785b1..f080354efec8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> @@ -245,7 +245,7 @@ static bool amdgpu_msi_ok(struct amdgpu_device *adev)
>  	return true;
>  }
>  
> -static void amdgpu_restore_msix(struct amdgpu_device *adev)
> +void amdgpu_restore_msix(struct amdgpu_device *adev)
>  {
>  	u16 ctrl;
>  
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> index aef5c216b191..f52bd7e6d988 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> @@ -149,5 +149,6 @@ void amdgpu_irq_gpu_reset_resume_helper(struct amdgpu_device *adev);
>  int amdgpu_irq_add_domain(struct amdgpu_device *adev);
>  void amdgpu_irq_remove_domain(struct amdgpu_device *adev);
>  unsigned amdgpu_irq_create_mapping(struct amdgpu_device *adev, unsigned src_id);
> +void amdgpu_restore_msix(struct amdgpu_device *adev);
>  
>  #endif