[Stable-8.1.5 02/11] vl: Improve error message for conflicting -incoming and -loadvm

[Michael Tokarev]

From: Kevin Wolf <kwolf@redhat.com>

Currently, the conflict between -incoming and -loadvm is only detected
when loading the snapshot fails because the image is still inactive for
the incoming migration. This results in a suboptimal error message:

$ ./qemu-system-x86_64 -hda /tmp/test.qcow2 -loadvm foo -incoming defer
qemu-system-x86_64: Device 'ide0-hd0' is writable but does not support snapshots

Catch the situation already in qemu_validate_options() to improve the
message:

$ ./qemu-system-x86_64 -hda /tmp/test.qcow2 -loadvm foo -incoming defer
qemu-system-x86_64: 'incoming' and 'loadvm' options are mutually exclusive

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231201142520.32255-3-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 5a7f21efaf99c60614fe1967be1c0f9aa46c526e)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/softmmu/vl.c b/softmmu/vl.c
index b0b96f67fa..c9e9ede237 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -2357,6 +2357,10 @@ static void qemu_validate_options(const QDict 
*machine_opts)
           }
     }
 
+    if (loadvm && incoming) {
+        error_report("'incoming' and 'loadvm' options are mutually exclusive");
+        exit(EXIT_FAILURE);
+    }
     if (loadvm && preconfig_requested) {
         error_report("'preconfig' and 'loadvm' options are "
                      "mutually exclusive");
-- 
2.39.2