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.

0 files changed, 0 insertions, 0 deletions