From c9e7d41a70dd2212a927f42fcf4acbddb733bdd7 Mon Sep 17 00:00:00 2001
From: Arthur Hanson Rasmusson <arthur@vgpu.io>
Date: Wed, 7 Oct 2026 14:02:27 -0400
Subject: vgsp: m98 - dump the program prologue (entry offset) and the
 param/const-0 page at launch

m97 settled the fetch question: zeros planted at the QMD's program offset
executed and trapped ILLEGAL_INSTR_ENCODING (0x9) at PC=0x109800 - the SM
instruction fetch and const reads through our shadows work; the m90-m96
MMU_NACK at PC=0x109880 is a memory access by the prologue instruction at
+0x80, almost certainly the first global load using a guest-VA device
pointer from the param buffer (c[0x0]). Dump the program page from the
entry offset (40 words) and the param page (16 words) so the access
instruction and its pointer arguments are visible in the log.
---
 kernel/gsp_phys_booter.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

(limited to 'kernel/gsp_phys_booter.c')

diff --git a/kernel/gsp_phys_booter.c b/kernel/gsp_phys_booter.c
index 28bf6f9..19fb67e 100644
--- a/kernel/gsp_phys_booter.c
+++ b/kernel/gsp_phys_booter.c
@@ -16444,6 +16444,37 @@ int gsp_phys_backend_guest_gr_submit(const struct gsp_phys_gr_submit *req,
 				       GSP_PHYS_PAGE_SIZE);
 				copied++;
 			}
+			/*
+			 * m98: dump the program prologue (qmd_word 48, from
+			 * the QMD's in-page entry offset) and the param/const-0
+			 * page (qmd_word 32, from page start) so the first
+			 * data-access instruction and the guest VA arguments it
+			 * fetches can be read from the log.
+			 */
+			if (pg->hpa && pg->qmd_word == 48u) {
+				u32 po = (qmd[48] &
+					  (GSP_PHYS_PAGE_SIZE - 1)) / 4;
+				const u32 *w = (const u32 *)sh_page + po;
+
+				pr_info("vgsp-gr: program +0x%x: %08x %08x %08x %08x %08x %08x %08x %08x | %08x %08x %08x %08x %08x %08x %08x %08x | %08x %08x %08x %08x %08x %08x %08x %08x | %08x %08x %08x %08x %08x %08x %08x %08x | %08x %08x %08x %08x %08x %08x %08x %08x\n",
+					po * 4,
+					w[0], w[1], w[2], w[3], w[4], w[5],
+					w[6], w[7], w[8], w[9], w[10], w[11],
+					w[12], w[13], w[14], w[15], w[16],
+					w[17], w[18], w[19], w[20], w[21],
+					w[22], w[23], w[24], w[25], w[26],
+					w[27], w[28], w[29], w[30], w[31],
+					w[32], w[33], w[34], w[35], w[36],
+					w[37], w[38], w[39]);
+			}
+			if (pg->hpa && pg->qmd_word == 32u) {
+				const u32 *w = (const u32 *)sh_page;
+
+				pr_info("vgsp-gr: param page: %08x %08x %08x %08x %08x %08x %08x %08x | %08x %08x %08x %08x %08x %08x %08x %08x\n",
+					w[0], w[1], w[2], w[3], w[4], w[5],
+					w[6], w[7], w[8], w[9], w[10], w[11],
+					w[12], w[13], w[14], w[15]);
+			}
 			for (j = 0; j < req->n_inl; j++) {
 				const struct gsp_phys_gr_inline *inl =
 					&req->inl[j];
-- 
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