[GIT PULL 08/14] hw/display/qxl: trace skipped stale loadvm commands

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

From: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>

Emit a trace event when qxl_post_load() drops a cursor or surface
command whose guest address no longer resolves, so a migration that
lands on a stale tracked pointer is visible instead of silent.

Message-ID: <20260825172051.435372-4-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
---
 hw/display/qxl.c        | 17 +++++++++++------
 hw/display/trace-events |  1 +
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index fb77f217b1c6..d5f9771f5af2 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -2461,6 +2461,8 @@ static int qxl_post_load(void *opaque, int version)
             }
             if (!qxl_loadvm_cmd_valid(d, d->guest_surfaces.cmds[in],
                                       QXL_CMD_SURFACE)) {
+                trace_qxl_post_load_stale_cmd(d->id, "surface",
+                                              d->guest_surfaces.cmds[in]);
                 continue;
             }
             cmds[out].cmd.data = d->guest_surfaces.cmds[in];
@@ -2468,12 +2470,15 @@ static int qxl_post_load(void *opaque, int version)
             cmds[out].group_id = MEMSLOT_GROUP_GUEST;
             out++;
         }
-        if (d->guest_cursor &&
-            qxl_loadvm_cmd_valid(d, d->guest_cursor, QXL_CMD_CURSOR)) {
-            cmds[out].cmd.data = d->guest_cursor;
-            cmds[out].cmd.type = QXL_CMD_CURSOR;
-            cmds[out].group_id = MEMSLOT_GROUP_GUEST;
-            out++;
+        if (d->guest_cursor) {
+            if (qxl_loadvm_cmd_valid(d, d->guest_cursor, QXL_CMD_CURSOR)) {
+                cmds[out].cmd.data = d->guest_cursor;
+                cmds[out].cmd.type = QXL_CMD_CURSOR;
+                cmds[out].group_id = MEMSLOT_GROUP_GUEST;
+                out++;
+            } else {
+                trace_qxl_post_load_stale_cmd(d->id, "cursor", d->guest_cursor);
+            }
         }
         qxl_spice_loadvm_commands(d, cmds, out);
         g_free(cmds);
diff --git a/hw/display/trace-events b/hw/display/trace-events
index 4bfc457fbac1..c5e7e42af23b 100644
--- a/hw/display/trace-events
+++ b/hw/display/trace-events
@@ -82,6 +82,7 @@ qxl_io_unexpected_vga_mode(int qid, uint64_t addr, uint64_t val, const char *des
 qxl_io_write(int qid, const char *mode, uint64_t addr, const char *aname, uint64_t val, unsigned size, int async) "%d %s addr=%"PRIu64 " (%s) val=%"PRIu64" size=%u async=%d"
 qxl_memslot_add_guest(int qid, uint32_t slot_id, uint64_t guest_start, uint64_t guest_end) "%d %u: guest phys 0x%"PRIx64 " - 0x%" PRIx64
 qxl_post_load(int qid, const char *mode) "%d %s"
+qxl_post_load_stale_cmd(int qid, const char *kind, uint64_t data) "%d skip stale %s cmd 0x%"PRIx64
 qxl_pre_load(int qid) "%d"
 qxl_pre_save(int qid) "%d"
 qxl_reset_surfaces(int qid) "%d"

-- 
2.55.0.543.g5ebe2ebe4ea8