vgsp: relocate a CODESRC-SUSPECT GR program page to the engine-mapped window-0 shadow instead of leaving the QMD pointer at an unmapped guest VA (eng33)

The client's MME-expanded draw builds a QMD whose program page (qmd[48])
classifies CODESRC-SUSPECT (empty-page): the engine's GPCCLIENT_GCC I-fetch
then read the guest VA above every engine-PDB window, raised FAULT_PDE and
the FIFO parked for the rest of the boot (the TSG re-arm cannot revive a
parked PBDMA). c361-c368 receipts.

With gsp_phys_gr_codesrc_reloc=1 (default) the builder copies the page into
the window-0 shadow (empty sources only; PTE/module pages are never
republished), overlays the client's own known-good SPH+SASS stage image at
the original QMD program offset (gsp_sema_gl_prog_img, stage-typed from the
section bind; truncated at a 128-bit boundary with a terminal EXIT when the
image is larger than the remaining page), and the existing QMD w48/49 +
prefetch rewrite publishes the shadow VA. If the shadow mapping cannot be
installed the page stays unmapped and the existing refusal drops the launch,
so an unmapped QMD program pointer is never published. 0 restores the old
guest-VA behaviour for a one-flip A/B.

Validation (c373, params-r1624): 31 CODESRC-RELOC events (img_len=384,
off=0xb00, 0 truncations), 51 GR LAUNCH submitted, 11 MME-FAST end
events=3, 79 FETCH-WIT with GP_GET advancing engine-fetched, 0 FAULT_PDE,
0 vgsp-fault, 0 WEDGE-REARM/PARK-RECOVER; work_gr backend_ok=35 fault=0.
The draws still write nothing (NOWRITE, no clear run in the emitted
window), so px0 stays 0 - the store wall is unchanged and is the next
target.

1 files changed, 5 insertions, 0 deletions

diff --git a/kernel/gsp_phys_gpu.h b/kernel/gsp_phys_gpu.h
index d2faa1e..7b95409 100644
--- a/kernel/gsp_phys_gpu.h
+++ b/kernel/gsp_phys_gpu.h
@@ -413,6 +413,11 @@ void gsp_phys_gr_vp_state_get(int *mode, u32 *words, u32 *n);
 /* m91: keep the forwarded QMD pointer pairs at the guest VAs (default 0). */
 int gsp_phys_rmcall_gr_ptr_guest_value(void);
 
+/* r1625: relocate a CODESRC-SUSPECT program page to an engine-mapped
+ * shadow page and rewrite the QMD pointer pair (default 1; 0 = the old
+ * guest-VA behaviour). */
+int gsp_phys_gr_codesrc_reloc_value(void);
+
 /* m95: program GPC MMU_CTRL from PFB MMU_CTRL before a forwarded launch. */
 int gsp_phys_rmcall_gr_gpc_mmu_init_value(void);