[Intel-gfx] [RFC PATCH v3 1/1] i915/drm: Split out x86/arm64 for run_as_guest

[Lucas De Marchi]

On Mon, Mar 21, 2022 at 04:34:49PM -0700, Casey Bowman wrote:
>Wanted to ping this older thread to find out where we stand with this patch,
>Are we OK with the current state of these changes?
>
>With more recent information gathered from feedback on other patches, would
>we prefer changing this to a more arch-neutral control flow?
>
>e.g.
>#if IS_ENABLED(CONFIG_X86)
>...
>#else
>...
>#endif
>
>Would we also prefer this RFC series be merged or would it be preferred to
>create a new series instead?

for this specific function, that is used in only 2 places I think it's
ok to do:

	static inline bool run_as_guest(void)
	{
	#if IS_ENABLED(CONFIG_X86)
		return !hypervisor_is_type(X86_HYPER_NATIVE);
	#else	
		/* Not supported yet */
		return false;	
	#endif
	}

For PCH it doesn't really matter as we don't execute that function
for discrete. For intel_vtd_active() I figure anything other than
x86 would be fine with false here.

Jani, that this look good to you?

Lucas De Marchi

>
>Regards,
>Casey
>
>On 2/15/22 15:41, Casey Bowman wrote:
>>Splitting out run_as_guest into platform-specific functions
>>as arm64 does not support this functionality.
>>
>>Signed-off-by: Casey Bowman <casey.g.bowman at intel.com>
>>---
>>  drivers/gpu/drm/i915/i915_drv.h | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>>diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>>index 1bca510a946d..fdec2b025540 100644
>>--- a/drivers/gpu/drm/i915/i915_drv.h
>>+++ b/drivers/gpu/drm/i915/i915_drv.h
>>@@ -1381,10 +1381,18 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
>>  #define INTEL_DISPLAY_ENABLED(dev_priv) \
>>  	(drm_WARN_ON(&(dev_priv)->drm, !HAS_DISPLAY(dev_priv)), !(dev_priv)->params.disable_display)
>>+#if IS_ENABLED(CONFIG_X86)
>>  static inline bool run_as_guest(void)
>>  {
>>  	return !hypervisor_is_type(X86_HYPER_NATIVE);
>>  }
>>+#elif IS_ENABLED(CONFIG_ARM64)
>>+static inline bool run_as_guest(void)
>>+{
>>+	/* Not supported for arm64, so we return false  */
>>+	return false;
>>+}
>>+#endif
>>  #define HAS_D12_PLANE_MINIMIZATION(dev_priv) (IS_ROCKETLAKE(dev_priv) || \
>>  					      IS_ALDERLAKE_S(dev_priv))
>