[Intel-gfx] [PATCH v2 1/5] drm/i915: introduced pv capability for vgpu

[Xiaolin Zhang]

This u32 pv_caps field is used to control the different
level pvmmio feature for MMIO emulation in GVT.

This field is default zero, no pvmmio feature enabled.

it also add VGT_CAPS_PVMMIO capability BIT for guest to check GVTg
can support PV feature or not.

v0: RFC, introudced enable_pvmmio module parameter.
v1: addressed RFC comment to remove enable_pvmmio module parameter
by pv capability check.
v2: rebase

Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
Cc: Zhi Wang <zhi.a.wang at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: He, Min <min.he at intel.com>
Cc: Jiang, Fei <fei.jiang at intel.com>
Cc: Gong, Zhipeng <zhipeng.gong at intel.com>
Cc: Yuan, Hang <hang.yuan at intel.com>
Cc: Zhiyuan Lv <zhiyuan.lv at intel.com>
Signed-off-by: Xiaolin Zhang <xiaolin.zhang at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h    | 11 +++++++++++
 drivers/gpu/drm/i915/i915_pvinfo.h | 17 ++++++++++++++++-
 drivers/gpu/drm/i915/i915_vgpu.c   | 19 +++++++++++++++++--
 3 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3017ef0..7b2d7cb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -56,6 +56,7 @@
 
 #include "i915_params.h"
 #include "i915_reg.h"
+#include "i915_pvinfo.h"
 #include "i915_utils.h"
 
 #include "intel_bios.h"
@@ -1343,6 +1344,7 @@ struct i915_workarounds {
 struct i915_virtual_gpu {
 	bool active;
 	u32 caps;
+	u32 pv_caps;
 };
 
 /* used in computing the new watermarks state */
@@ -2853,6 +2855,11 @@ static inline bool intel_vgpu_active(struct drm_i915_private *dev_priv)
 	return dev_priv->vgpu.active;
 }
 
+static inline bool intel_vgpu_has_pvmmio(struct drm_i915_private *dev_priv)
+{
+	return dev_priv->vgpu.caps & VGT_CAPS_PVMMIO;
+}
+
 u32 i915_pipestat_enable_mask(struct drm_i915_private *dev_priv,
 			      enum pipe pipe);
 void
@@ -3878,4 +3885,8 @@ static inline int intel_hws_csb_write_index(struct drm_i915_private *i915)
 		return I915_HWS_CSB_WRITE_INDEX;
 }
 
+#define PVMMIO_LEVEL_ENABLE(dev_priv, level)	\
+	(intel_vgpu_active(dev_priv) && intel_vgpu_has_pvmmio(dev_priv) \
+			&& (dev_priv->vgpu.pv_caps & level))
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h b/drivers/gpu/drm/i915/i915_pvinfo.h
index eeaa3d5..26709e8 100644
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -49,12 +49,26 @@ enum vgt_g2v_type {
 	VGT_G2V_MAX,
 };
 
+#define VGPU_PVMMIO(vgpu) vgpu_vreg_t(vgpu, vgtif_reg(enable_pvmmio))
+
 /*
  * VGT capabilities type
  */
 #define VGT_CAPS_FULL_48BIT_PPGTT	BIT(2)
 #define VGT_CAPS_HWSP_EMULATION		BIT(3)
 #define VGT_CAPS_HUGE_GTT		BIT(4)
+#define VGT_CAPS_PVMMIO		BIT(5)
+
+/*
+ * define different levels of PVMMIO optimization
+ */
+enum pvmmio_levels {
+	PVMMIO_ELSP_SUBMIT = 0x1,
+	PVMMIO_PLANE_UPDATE = 0x2,
+	PVMMIO_PLANE_WM_UPDATE = 0x4,
+	PVMMIO_MASTER_IRQ = 0x8,
+	PVMMIO_PPGTT_UPDATE = 0x10,
+};
 
 struct vgt_if {
 	u64 magic;		/* VGT_MAGIC */
@@ -106,8 +120,9 @@ struct vgt_if {
 
 	u32 execlist_context_descriptor_lo;
 	u32 execlist_context_descriptor_hi;
+	u32 enable_pvmmio;
 
-	u32  rsv7[0x200 - 24];    /* pad to one page */
+	u32  rsv7[0x200 - 25];    /* pad to one page */
 } __packed;
 
 #define vgtif_reg(x) \
diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index 869cf4a..907bbd2 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -76,9 +76,24 @@ void i915_check_vgpu(struct drm_i915_private *dev_priv)
 	}
 
 	dev_priv->vgpu.caps = __raw_i915_read32(dev_priv, vgtif_reg(vgt_caps));
-
 	dev_priv->vgpu.active = true;
-	DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
+
+	if (!intel_vgpu_has_pvmmio(dev_priv)) {
+		DRM_INFO("Virtual GPU for Intel GVT-g detected\n");
+		return;
+	}
+
+	/* If guest wants to enable pvmmio, it needs to enable it explicitly
+	 * through vgt_if interface, and then read back the enable state from
+	 * gvt layer.
+	 */
+	__raw_i915_write32(dev_priv, vgtif_reg(enable_pvmmio),
+			dev_priv->vgpu.pv_caps);
+	dev_priv->vgpu.pv_caps = __raw_i915_read32(dev_priv,
+			vgtif_reg(enable_pvmmio));
+
+	DRM_INFO("Virtual GPU for Intel GVT-g detected with pvmmio 0x%x\n",
+			dev_priv->vgpu.pv_caps);
 }
 
 bool intel_vgpu_has_full_48bit_ppgtt(struct drm_i915_private *dev_priv)
-- 
2.7.4