[Intel-gfx] [RFC 02/29] drm/i915: Introduce host graphics memory balloon for gvt

[Zhi Wang]

From: Bing Niu <bing.niu at intel.com>

This patch introduces host graphics memory ballon when GVT-g is enabled.

As under GVT-g, i915 only owned limited graphics resources, others are
managed by GVT-g resource allocator and kept for other vGPUs.

For graphics memory space partition, a typical layout looks like:

+-------+-----------------------+------+-----------------------+
|* Host |   *GVT-g Resource     |* Host|   *GVT-g Resource     |
| Owned |   Allocator Managed   | Owned|   Allocator Managed   |
|       |                       |      |                       |
+---------------+-------+----------------------+-------+-------+
|       |       |       |       |      |       |       |       |
| i915  | vm 1  | vm 2  | vm 3  | i915 | vm 1  | vm 2  | vm 3  |
|       |       |       |       |      |       |       |       |
+-------+-------+-------+--------------+-------+-------+-------+
|           Aperture            |            Hidden            |
+-------------------------------+------------------------------+
|                       GGTT memory space                      |
+--------------------------------------------------------------+

Similar with fence registers partition:

 +------ +-----------------------+
 | * Host|    GVT-g Resource     |
 | Owned |   Allocator Managed   +
 0       |                       31
 +---------------+-------+-------+
 |       |       |       |       |
 | i915  | vm 1  | vm 2  | vm 3  |
 |       |       |       |       |
 +-------+-------+-------+-------+

i915 host will read the amount of allocated resources via GVT-g kernel parameters.

Signed-off-by: Bing Niu <bing.niu at intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
---
 drivers/gpu/drm/i915/gvt/params.h   |  3 +++
 drivers/gpu/drm/i915/i915_gem.c     |  3 +++
 drivers/gpu/drm/i915/i915_gem_gtt.c |  4 ++--
 drivers/gpu/drm/i915/i915_vgpu.c    | 16 ++++++++++++----
 drivers/gpu/drm/i915/i915_vgpu.h    |  1 +
 5 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/params.h b/drivers/gpu/drm/i915/gvt/params.h
index d2955b9..0656a98 100644
--- a/drivers/gpu/drm/i915/gvt/params.h
+++ b/drivers/gpu/drm/i915/gvt/params.h
@@ -27,6 +27,9 @@
 struct gvt_kernel_params {
 	bool enable;
 	int debug;
+	int dom0_low_gm_sz;
+	int dom0_high_gm_sz;
+	int dom0_fence_sz;
 };
 
 extern struct gvt_kernel_params gvt;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 799a53a..e916e43 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5080,6 +5080,9 @@ i915_gem_load(struct drm_device *dev)
 	else
 		dev_priv->num_fence_regs = 8;
 
+	if(intel_gvt_host_active(dev))
+		dev_priv->num_fence_regs = gvt.dom0_fence_sz;
+
 	if (intel_vgpu_active(dev))
 		dev_priv->num_fence_regs =
 				I915_READ(vgtif_reg(avail_rs.fence_num));
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 7377b67..0540de2 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2713,7 +2713,7 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 	i915_address_space_init(ggtt_vm, dev_priv);
 	ggtt_vm->total += PAGE_SIZE;
 
-	if (intel_vgpu_active(dev)) {
+	if (intel_vgpu_active(dev) || intel_gvt_host_active(dev)) {
 		ret = intel_vgt_balloon(dev);
 		if (ret)
 			return ret;
@@ -2810,7 +2810,7 @@ void i915_global_gtt_cleanup(struct drm_device *dev)
 	}
 
 	if (drm_mm_initialized(&vm->mm)) {
-		if (intel_vgpu_active(dev))
+		if (intel_vgpu_active(dev) || intel_gvt_host_active(dev))
 			intel_vgt_deballoon();
 
 		drm_mm_takedown(&vm->mm);
diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index dea7429..fbe6114 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -188,10 +188,18 @@ int intel_vgt_balloon(struct drm_device *dev)
 	unsigned long unmappable_base, unmappable_size, unmappable_end;
 	int ret;
 
-	mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
-	mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
-	unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
-	unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));
+	if(intel_gvt_host_active(dev)) {
+		mappable_base = 0;
+		mappable_size = gvt.dom0_low_gm_sz << 20;
+		unmappable_base = dev_priv->gtt.mappable_end;
+		unmappable_size = gvt.dom0_high_gm_sz << 20;
+	} else if (intel_vgpu_active(dev)) {
+		mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
+		mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
+		unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
+		unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));
+	} else
+		return -ENODEV;
 
 	mappable_end = mappable_base + mappable_size;
 	unmappable_end = unmappable_base + unmappable_size;
diff --git a/drivers/gpu/drm/i915/i915_vgpu.h b/drivers/gpu/drm/i915/i915_vgpu.h
index 942490a..b8a49e6 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.h
+++ b/drivers/gpu/drm/i915/i915_vgpu.h
@@ -24,6 +24,7 @@
 #ifndef _I915_VGPU_H_
 #define _I915_VGPU_H_
 
+#include "gvt/params.h"
 /* The MMIO offset of the shared info between guest and host emulator */
 #define VGT_PVINFO_PAGE	0x78000
 #define VGT_PVINFO_SIZE	0x1000
-- 
1.9.1