kernel: enlarge the pin table and its probe window; tools: bridge client mappings into the service

The pin table became the primary VA->PA store once push-buffer regions and
bridged client mappings started adding thousands of pages per boot; at
8192 slots with an 8-probe window, inserts were silently dropped and
lookups missed at half load. 32768 slots and a 32-probe window keep the
mapped set intact.

tools/guest-diag/{guest_pmap_all.py,bridge_sems.sh} translate the CUDA
client's /dev/nvidia* mappings through the guest's own pagemap and inject
each present page into the service as a sysmem pin. With the client's
semaphore pages pinned the service applies their releases into the page
the client polls (verified: applied 67 -> 109, misses stop growing for
those VAs), where before every write went to the vidmem shadow.

1 files changed, 38 insertions, 0 deletions

diff --git a/tools/guest-diag/guest_pmap_all.py b/tools/guest-diag/guest_pmap_all.py
new file mode 100644
index 0000000..1a4df34
--- /dev/null
+++ b/tools/guest-diag/guest_pmap_all.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+# guest-side helper: dump present pages of the target's /dev/nvidia* mappings
+# as "va,pa" lines (root in the guest), starting at or above va-min and
+# stopping after max-pairs lines so the guest agent's output stays small.
+# Usage: sudo python3 guest_pmap_all.py <pid> [va-min-hex] [max-pairs]
+import os
+import sys
+
+pid = int(sys.argv[1])
+va_min = int(sys.argv[2], 16) if len(sys.argv) > 2 else 0
+maxp = int(sys.argv[3]) if len(sys.argv) > 3 else 300
+
+regions = []
+with open('/proc/%d/maps' % pid) as f:
+    for line in f:
+        parts = line.split()
+        a, b = parts[0].split('-')
+        lo, hi = int(a, 16), int(b, 16)
+        path = parts[5] if len(parts) >= 6 else ''
+        if 'nvidia' in path:
+            regions.append((max(lo, va_min), hi))
+
+fd = os.open('/proc/%d/pagemap' % pid, os.O_RDONLY)
+n = 0
+try:
+    for lo, hi in regions:
+        for va in range(lo, hi, 0x1000):
+            os.lseek(fd, (va // 4096) * 8, 0)
+            e = int.from_bytes(os.read(fd, 8), 'little')
+            if not ((e >> 63) & 1):
+                continue
+            pfn = e & ((1 << 55) - 1)
+            print('0x%x,0x%x' % (va, (pfn << 12)))
+            n += 1
+            if n >= maxp:
+                raise SystemExit
+finally:
+    os.close(fd)
\ No newline at end of file