vgsp: m99 - identity-map the forwarded kernel's guest data pages into the engine tree

The m97/m98 decode proved the SM instruction fetch and const reads work;
the wall is the kernel's first global data access (prologue instruction at
+0x80) to a guest-VA device pointer (param page words 6..9 carry the demo's
two 16MB buffers at 0x763dXXXXXXXX), which is not mapped in the engine's
page tables. The walker walks OUR root->PD2->PD1->PD0->PT tree (SC PDB ==
our VASPDB chunk, proven by matching the same-run INST base to the PDB-root
DMA log), and fresh direct-planted tables are visible at first fetch.

Service side (gsp_sema_service.c): svc_gr_data_fill() scans the param
(c[0x0]) page for plausible device VAs, resolves the containing 2MB windows
(-1..+16 windows, early stop when a window resolves nothing) via
svc_resolve_va on the service thread, and carries {va, pa} in
svc_fwd_req.gr_data; svc_fwd_gr_work() converts PA->HPA and attaches the
list to the submit.

Backend (gsp_phys_booter.c): gsp_phys_rmcall_gr_data_map() plants VA->HPA
leaf PTEs (GENERIC_MEMORY kind 0x06, like UVM/RM on Turing) into lazily
allocated PD1/PD0/PT chunk branches under root[0] (VAs < 2^47), caching
branches per index; the submit maps all req->data pages before publish and
logs the count.

1 files changed, 8 insertions, 0 deletions

diff --git a/kernel/gsp_phys_booter.h b/kernel/gsp_phys_booter.h
index e46fb86..29cf07f 100644
--- a/kernel/gsp_phys_booter.h
+++ b/kernel/gsp_phys_booter.h
@@ -362,6 +362,12 @@ struct gsp_phys_gr_inline {
 	u8 data[GSP_PHYS_GR_INLINE_BYTES];
 };
 
+/* m99: one guest data page identity-mapped into the engine's page tree. */
+struct gsp_phys_gr_data_page {
+	u64 va;		/* guest VA, page aligned */
+	u64 hpa;	/* host PA, page aligned */
+};
+
 struct gsp_phys_gr_submit {
 	const u32 *qmd;		/* 64 rewritten-QMD source words */
 	u32 qmd_words;		/* must be GSP_PHYS_GR_QMD_WORDS */
@@ -382,6 +388,8 @@ struct gsp_phys_gr_submit {
 	u32 n_pages;
 	const struct gsp_phys_gr_inline *inl;
 	u32 n_inl;
+	const struct gsp_phys_gr_data_page *data;	/* m99: identity pages */
+	u32 n_data;
 	u64 rel_hpa;		/* guest-visible QMD release0 page, or 0 */
 	u32 rel_off;
 	u32 rel_payload;