[Intel-gfx] [PATCH 6/7] drm/i915: guest i915 notification for Intel-GVTg

[Zhiyuan Lv]

When i915 drivers run inside a VM with Intel-GVTg, some explicit
notifications are needed from guest to host device model through PV
INFO page write. The notifications include:

	PPGTT create/destroy
	EXECLIST create/destroy

They are used for the shadow implementation of PPGTT and EXECLIST
context. Intel GVT-g needs to write-protect the guest pages of PPGTT
and contexts, and clear the write protection when they end their life
cycle.

Signed-off-by: Zhiyuan Lv <zhiyuan.lv at intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 41 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_lrc.c    | 25 ++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 823005c..00dafb0 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -896,6 +896,41 @@ static int gen8_init_scratch(struct i915_address_space *vm)
 	return 0;
 }
 
+static int gen8_ppgtt_notify_vgt(struct i915_hw_ppgtt *ppgtt, bool create)
+{
+	enum vgt_g2v_type msg;
+	struct drm_device *dev = ppgtt->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned int offset = vgtif_reg(pdp0_lo);
+	int i;
+
+	if (USES_FULL_48BIT_PPGTT(dev)) {
+		u64 daddr = px_dma(&ppgtt->pml4);
+
+		I915_WRITE(offset, daddr & 0xffffffff);
+		I915_WRITE(offset + 4, daddr >> 32);
+
+		msg = (create ? VGT_G2V_PPGTT_L4_PAGE_TABLE_CREATE :
+				VGT_G2V_PPGTT_L4_PAGE_TABLE_DESTROY);
+	} else {
+		for (i = 0; i < GEN8_LEGACY_PDPES; i++) {
+			u64 daddr = i915_page_dir_dma_addr(ppgtt, i);
+
+			I915_WRITE(offset, daddr & 0xffffffff);
+			I915_WRITE(offset + 4, daddr >> 32);
+
+			offset += 8;
+		}
+
+		msg = (create ? VGT_G2V_PPGTT_L3_PAGE_TABLE_CREATE :
+				VGT_G2V_PPGTT_L3_PAGE_TABLE_DESTROY);
+	}
+
+	I915_WRITE(vgtif_reg(g2v_notify), msg);
+
+	return 0;
+}
+
 static void gen8_free_scratch(struct i915_address_space *vm)
 {
 	struct drm_device *dev = vm->dev;
@@ -942,6 +977,9 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
 	struct i915_hw_ppgtt *ppgtt =
 		container_of(vm, struct i915_hw_ppgtt, base);
 
+	if (intel_vgpu_active(vm->dev))
+		gen8_ppgtt_notify_vgt(ppgtt, false);
+
 	if (!USES_FULL_48BIT_PPGTT(ppgtt->base.dev))
 		gen8_ppgtt_cleanup_3lvl(ppgtt->base.dev, &ppgtt->pdp);
 	else
@@ -1516,6 +1554,9 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
 		}
 	}
 
+	if (intel_vgpu_active(ppgtt->base.dev))
+		gen8_ppgtt_notify_vgt(ppgtt, true);
+
 	return 0;
 
 free_scratch:
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 4b2ac37..80d424b 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -136,6 +136,7 @@
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
 #include "intel_mocs.h"
+#include "i915_vgpu.h"
 
 #define GEN9_LR_CONTEXT_RENDER_SIZE (22 * PAGE_SIZE)
 #define GEN8_LR_CONTEXT_RENDER_SIZE (20 * PAGE_SIZE)
@@ -2122,6 +2123,22 @@ make_rpcs(struct drm_device *dev)
 	return rpcs;
 }
 
+static void intel_lr_context_notify_vgt(struct intel_context *ctx,
+					struct intel_engine_cs *ring,
+					int msg)
+{
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u64 tmp = intel_lr_context_descriptor(ctx, ring);
+
+	I915_WRITE(vgtif_reg(execlist_context_descriptor_lo),
+			tmp & 0xffffffff);
+	I915_WRITE(vgtif_reg(execlist_context_descriptor_hi),
+			tmp >> 32);
+
+	I915_WRITE(vgtif_reg(g2v_notify), msg);
+}
+
 static int
 populate_lr_context(struct intel_context *ctx, struct drm_i915_gem_object *ctx_obj,
 		    struct intel_engine_cs *ring, struct intel_ringbuffer *ringbuf)
@@ -2282,6 +2299,10 @@ void intel_lr_context_free(struct intel_context *ctx)
 					ctx->engine[i].ringbuf;
 			struct intel_engine_cs *ring = ringbuf->ring;
 
+			if (intel_vgpu_active(ringbuf->ring->dev))
+				intel_lr_context_notify_vgt(ctx, ring,
+					VGT_G2V_EXECLIST_CONTEXT_DESTROY);
+
 			if ((ctx == ring->default_context) ||
 			    (intel_vgpu_active(ring->dev))) {
 				intel_unpin_ringbuffer_obj(ringbuf);
@@ -2439,6 +2460,10 @@ int intel_lr_context_deferred_create(struct intel_context *ctx,
 	ctx->engine[ring->id].ringbuf = ringbuf;
 	ctx->engine[ring->id].state = ctx_obj;
 
+	if (intel_vgpu_active(dev))
+		intel_lr_context_notify_vgt(ctx, ring,
+				VGT_G2V_EXECLIST_CONTEXT_CREATE);
+
 	if (ctx == ring->default_context)
 		lrc_setup_hardware_status_page(ring, ctx_obj);
 	else if (ring->id == RCS && !ctx->rcs_initialized) {
-- 
1.9.1