[Intel-gfx] [PATCH v3] drm/i915/gvt: return the actual aperture size under gvt environment

[Li, Weinan Z]

Hi Joonas/Chris, do you have any comments?
I've asked OCL team for this patch, they also agree to use available aperture size
for max allocation buffer definition, code confirmation ongoing.

> -----Original Message-----
> From: Li, Weinan Z
> Sent: Wednesday, May 3, 2017 8:51 AM
> To: intel-gfx at lists.freedesktop.org; intel-gvt-dev at lists.freedesktop.org
> Cc: Li, Weinan Z <weinan.z.li at intel.com>
> Subject: [PATCH v3] drm/i915/gvt: return the actual aperture size under gvt
> environment
> 
> I915_GEM_GET_APERTURE ioctl is used to probe aperture size from userspace.
> In gvt environment, each vm only use the ballooned part of aperture, so we
> should return the actual available aperture size exclude the reserved part by
> balloon.
> 
> v2: add 'reserved' in struct i915_address_space to record the reserved size in
> ggtt by balloon.
> 
> v3: remain aper_size as total, adjust aper_available_size exclude reserved and
> pinned. UMD driver need to adjust the max allocation size according to the
> available aperture size but not total size.
> 
> Signed-off-by: Weinan Li <weinan.z.li at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem.c     | 7 +++----
>  drivers/gpu/drm/i915/i915_gem_gtt.h | 3 ++-
>  drivers/gpu/drm/i915/i915_vgpu.c    | 5 ++++-
>  3 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c
> b/drivers/gpu/drm/i915/i915_gem.c index 84ea249..e84576c 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -145,9 +145,8 @@ int i915_mutex_lock_interruptible(struct drm_device
> *dev)
>  	struct i915_ggtt *ggtt = &dev_priv->ggtt;
>  	struct drm_i915_gem_get_aperture *args = data;
>  	struct i915_vma *vma;
> -	size_t pinned;
> +	size_t pinned = 0;
> 
> -	pinned = 0;
>  	mutex_lock(&dev->struct_mutex);
>  	list_for_each_entry(vma, &ggtt->base.active_list, vm_link)
>  		if (i915_vma_is_pinned(vma))
> @@ -158,8 +157,8 @@ int i915_mutex_lock_interruptible(struct drm_device
> *dev)
>  	mutex_unlock(&dev->struct_mutex);
> 
>  	args->aper_size = ggtt->base.total;
> -	args->aper_available_size = args->aper_size - pinned;
> -
> +	args->aper_available_size = args->aper_size
> +			- ggtt->base.reserved - pinned;
>  	return 0;
>  }
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h
> b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index fb15684..bdf832d 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -255,7 +255,8 @@ struct i915_address_space {
>  	struct drm_i915_file_private *file;
>  	struct list_head global_link;
>  	u64 total;		/* size addr space maps (ex. 2GB for ggtt) */
> -
> +	/* size addr space reserved by GVT balloon, only used for ggtt */
> +	u64 reserved;
>  	bool closed;
> 
>  	struct i915_page_dma scratch_page;
> diff --git a/drivers/gpu/drm/i915/i915_vgpu.c
> b/drivers/gpu/drm/i915/i915_vgpu.c
> index 4ab8a97..58055a9 100644
> --- a/drivers/gpu/drm/i915/i915_vgpu.c
> +++ b/drivers/gpu/drm/i915/i915_vgpu.c
> @@ -183,7 +183,7 @@ int intel_vgt_balloon(struct drm_i915_private
> *dev_priv)
> 
>  	unsigned long mappable_base, mappable_size, mappable_end;
>  	unsigned long unmappable_base, unmappable_size, unmappable_end;
> -	int ret;
> +	int ret, i;
> 
>  	if (!intel_vgpu_active(dev_priv))
>  		return 0;
> @@ -242,6 +242,9 @@ int intel_vgt_balloon(struct drm_i915_private
> *dev_priv)
>  			goto err;
>  	}
> 
> +	for (i = 0; i < ARRAY_SIZE(bl_info.space); i++)
> +		ggtt->base.reserved += bl_info.space[i].size;
> +
>  	DRM_INFO("VGT balloon successfully\n");
>  	return 0;
> 
> --
> 1.9.1