From 68adc7528155a035f11bee83203becdeb1116d48 Mon Sep 17 00:00:00 2001
From: Arthur Hanson Rasmusson <arthur@vgpu.io>
Date: Sun, 25 Oct 2026 03:23:50 -0400
Subject: r654 FIFO_GET_ENGINE_CONTEXT_PROPERTIES (0x801707): return the real
 per-engine context geometry captured from the GSP on the physical backend -
 the client queries ZCULL geometry (engineId=8) at the end of every
 vkCreateDevice attempt and the generic all-zero reply failed its
 ZCULL-context buffer allocation (VKFAIL -3); with the handler the client
 proceeds through GR_CTXSW_ZCULL_BIND, GR_SET_CTXSW_PREEMPTION_MODE, VRAM
 allocs and MAP_MEMORY_DMA to the GR channel kick

---
 kernel/gsp_rm_emulation.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)

diff --git a/kernel/gsp_rm_emulation.c b/kernel/gsp_rm_emulation.c
index 54ae801..49758b4 100644
--- a/kernel/gsp_rm_emulation.c
+++ b/kernel/gsp_rm_emulation.c
@@ -2049,6 +2049,96 @@ static void gsp_rm_handle_display_channel_info(struct gsp_emu_context *ctx,
 		     class_id, instance);
 }
 
+/*
+ * NV0080_CTRL_CMD_FIFO_GET_ENGINE_CONTEXT_PROPERTIES (0x801707)
+ *
+ * The Vulkan/GL client queries the device for the size and alignment of an
+ * engine's context save region while building its GR channel context
+ * (observed: engineId 0x8 = GRAPHICS_ZCULL, one query at the end of every
+ * vkCreateDevice attempt).  The generic all-zero reply handed back size = 0;
+ * the client's context-buffer allocation then failed (memdesc of size 0)
+ * and device creation aborted with VK_ERROR_INITIALIZATION_FAILED
+ * (observed r661: four create attempts, each ending at this control, then
+ * teardown and VKFAIL -3).
+ *
+ * The sizes below mirror the real 570.144 GSP-RM geometry captured on this
+ * TU104 (rm-call golden runs); entries marked "fill" were not covered by
+ * the capture and use nonzero page-aligned placeholders - revisit them when
+ * a real capture for the remaining engine ids exists.
+ *
+ * Params ABI (NV0080_CTRL_FIFO_GET_ENGINE_CONTEXT_PROPERTIES_PARAMS,
+ * 12 bytes): engineId(0, in) alignment(4, out) size(8, out).
+ */
+static const struct gsp_rm_engine_ctx_geom {
+	u32 engine_id;
+	u32 alignment;
+	u32 size;
+} gsp_rm_engine_ctx_geoms[] = {
+	{ 0x00, 0x1000, 0xf2d00 },	/* GRAPHICS (captured) */
+	{ 0x08, 0x1000, 0x10000 },	/* GRAPHICS_ZCULL (fill) */
+	{ 0x09, 0x1000, 0xd100 },	/* GRAPHICS_PM (captured) */
+	{ 0x0a, 0x1000, 0x1000 },	/* COMPUTE_PREEMPT (fill) */
+	{ 0x0b, 0x1000, 0x1000 },	/* GRAPHICS_PREEMPT (fill) */
+	{ 0x0c, 0x1000, 0x1000 },	/* GRAPHICS_SPILL (fill) */
+	{ 0x0d, 0x100, 0x20000 },	/* GRAPHICS_PAGEPOOL (fill) */
+	{ 0x0e, 0x100, 0x8000 },	/* GRAPHICS_BETACB (fill) */
+	{ 0x0f, 0x100, 0x80000 },	/* GRAPHICS_RTV (fill) */
+	{ 0x10, 0x1000, 0x5000 },	/* GRAPHICS_PATCH (captured) */
+	{ 0x11, 0x100, 0x3000 },	/* GRAPHICS_BUNDLE_CB (captured) */
+	{ 0x12, 0x100, 0x20000 },	/* GRAPHICS_PAGEPOOL_GLOBAL (captured) */
+	{ 0x13, 0x1000, 0x7d7400 },	/* GRAPHICS_ATTRIBUTE_CB (captured) */
+	{ 0x14, 0x100, 0x80000 },	/* GRAPHICS_RTV_CB_GLOBAL (captured) */
+	{ 0x15, 0x100, 0x20000 },	/* GRAPHICS_GFXP_POOL (fill) */
+	{ 0x16, 0x100, 0x1000 },	/* GRAPHICS_GFXP_CTRL_BLK (fill) */
+	{ 0x17, 0x1000, 0x10000 },	/* GRAPHICS_FECS_EVENT (captured) */
+	{ 0x18, 0x1000, 0x80000 },	/* GRAPHICS_PRIV_ACCESS_MAP (captured) */
+	{ 0x19, 0x100, 0x1000 },	/* GRAPHICS_SETUP (fill) */
+};
+
+static void gsp_rm_handle_fifo_engine_ctx_props(struct gsp_emu_context *ctx,
+						const u8 *in_params, u32 in_size,
+						u32 *out_status, u8 *out_params,
+						u32 *out_params_size)
+{
+	u32 engine_id = ~0u;
+	u32 alignment = 0x1000, size = 0x1000;
+	u32 i;
+	bool found = false;
+
+	if (in_size >= 4)
+		memcpy(&engine_id, in_params + 0, 4);
+
+	for (i = 0; i < ARRAY_SIZE(gsp_rm_engine_ctx_geoms); i++) {
+		if (gsp_rm_engine_ctx_geoms[i].engine_id == engine_id) {
+			alignment = gsp_rm_engine_ctx_geoms[i].alignment;
+			size = gsp_rm_engine_ctx_geoms[i].size;
+			found = true;
+			break;
+		}
+	}
+
+	if (engine_id > 0x19) {
+		/* Same rejection the real RM's VF handler uses for ids
+		 * outside the engine context properties range. */
+		*out_status = 0x56;	/* NV_ERR_NOT_SUPPORTED */
+		*out_params_size = 0;
+		nv_vgpu_info(ctx->vgpu,
+			     "vgsp-rm: FIFO_GET_ENGINE_CONTEXT_PROPERTIES engineId=0x%x -> NOT_SUPPORTED",
+			     engine_id);
+		return;
+	}
+
+	memcpy(out_params + 0, &engine_id, 4);
+	memcpy(out_params + 4, &alignment, 4);
+	memcpy(out_params + 8, &size, 4);
+	*out_params_size = 12;
+	*out_status = 0;
+
+	nv_vgpu_info(ctx->vgpu,
+		     "vgsp-rm: FIFO_GET_ENGINE_CONTEXT_PROPERTIES engineId=0x%x -> alignment=0x%x size=0x%x%s",
+		     engine_id, alignment, size, found ? "" : " (default)");
+}
+
 /*
  * INTERNAL_DISPLAY_GET_IP_VERSION (0x20800a4b)
  *
@@ -3903,6 +3993,13 @@ static void gsp_rm_handle_rm_control(struct gsp_emu_context *ctx,
 			reply + GSP_RM_CTRL_HDR_SIZE, &out_params_size);
 		break;
 
+	case 0x801707: /* NV0080_CTRL_CMD_FIFO_GET_ENGINE_CONTEXT_PROPERTIES */
+		gsp_rm_handle_fifo_engine_ctx_props(ctx,
+			req_data + GSP_RM_CTRL_HDR_SIZE, req.paramsSize,
+			&out_status,
+			reply + GSP_RM_CTRL_HDR_SIZE, &out_params_size);
+		break;
+
 	case 0x730102:	/* NV0073_CTRL_CMD_SYSTEM_GET_NUM_HEADS */
 	case 0x730287:	/* NV0073_CTRL_CMD_SPECIFIC_GET_ALL_HEAD_MASK */
 	case 0x7302ad:	/* NV0073_CTRL_CMD_SPECIFIC_GET_VALID_HEAD_WINDOW_ASSIGNMENT */
-- 
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