[Intel-gfx] [PATCH v3 1/8] drm/i915: introduced pv capability for vgpu

[Xiaolin Zhang]

both u32 pv_caps field and pvmmio_caps are used to control the different
level pvmmio feature for MMIO emulation in both guest and GVT.

These fields are default zero, no pvmmio feature enabled.

it also adds 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
v3: distinct pv caps from guest and host. renamed enable_pvmmio to
pvmmio_caps which is used for host pv caps.

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 | 16 +++++++++++++++-
 drivers/gpu/drm/i915/i915_vgpu.c   | 23 +++++++++++++++++++++--
 3 files changed, 47 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..78a4b9c 100644
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -55,6 +55,18 @@ enum vgt_g2v_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 */
@@ -107,7 +119,9 @@ struct vgt_if {
 	u32 execlist_context_descriptor_lo;
 	u32 execlist_context_descriptor_hi;
 
-	u32  rsv7[0x200 - 24];    /* pad to one page */
+	u32 pvmmio_caps;
+
+	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..219c7c0 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -62,6 +62,7 @@ void i915_check_vgpu(struct drm_i915_private *dev_priv)
 {
 	u64 magic;
 	u16 version_major;
+	u32 gvt_caps;
 
 	BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
 
@@ -76,9 +77,27 @@ 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.
+	 */
+	gvt_caps = __raw_i915_read32(dev_priv, vgtif_reg(pvmmio_caps));
+	dev_priv->vgpu.pv_caps &= gvt_caps;
+	__raw_i915_write32(dev_priv, vgtif_reg(pvmmio_caps),
+			dev_priv->vgpu.pv_caps);
+	if (!dev_priv->vgpu.pv_caps)
+		return;
+
+
+	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