[PATCH v2] drm/i915: Fix GVT-g PVINFO version compatibility check

[Joonas Lahtinen]

On to, 2017-06-08 at 14:58 +0800, Zhenyu Wang wrote:
> Current it's strictly checked if PVINFO version matches 1.0
> for GVT-g i915 guest which doesn't help for compatibility at
> all and forces GVT-g host can't extend PVINFO easily with version
> bump for real compatibility check.
> 
> This fixes that to check minimal required PVINFO version instead.
> 
> v2:
> - drop unneeded version macro
> - use only major version for sanity check
> 
> Cc: Chuanxiao Dong <chuanxiao.dong at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: stable at vger.kernel.org # v4.10+
> Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>

<SNIP>

> +++ b/drivers/gpu/drm/i915/i915_vgpu.c
> @@ -61,7 +61,7 @@
>  void i915_check_vgpu(struct drm_i915_private *dev_priv)
>  {
>  	uint64_t magic;
> -	uint32_t version;
> +	uint32_t version_major;

Just a final tune, change these types into u64 and u32 respectively.

>  
>  	BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
>  
> @@ -69,10 +69,9 @@ void i915_check_vgpu(struct drm_i915_private *dev_priv)
>  	if (magic != VGT_MAGIC)
>  		return;
>  
> -	version = INTEL_VGT_IF_VERSION_ENCODE(
> -		__raw_i915_read16(dev_priv, vgtif_reg(version_major)),
> -		__raw_i915_read16(dev_priv, vgtif_reg(version_minor)));
> -	if (version != INTEL_VGT_IF_VERSION) {
> +	version_major = __raw_i915_read16(dev_priv,
> +					  vgtif_reg(version_major));

This assignment fits a single line now.

Then this is;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation