test: move wait_for_machine into util.sh

The vmspawn-based TEST-87 subtests each carried a near-identical
wait_for_machine() helper. Move it into util.sh so it can be shared.
The shared version is the vmspawn.sh variant, which tells missing
vhost-user-fs (nested VM) apart from any other early exit. As a result,
bin-volume and replace-storage now use that distinction too instead of
treating every early exit alike. vmspawn-drives is unaffected of this,
its --image-only console never matches the vhost-user-fs marker, so an
early exit still fails.

Signed-off-by: Paul Meyer <katexochen0@gmail.com>

test/units/TEST-87-AUX-UTILS-VM.bind-volume.sh

@@ -90,24 +90,6 @@ mke2fs -t ext4 -q -d "$WORKDIR/rootfs" "$WORKDIR/root.raw"
 BOOT_VOL="test-bind-volume-boot-$$"
 RUNTIME_VOL="test-bind-volume-runtime-$$"
 
-wait_for_machine() {
-    local machine="$1" pid="$2" log="$3"
-    timeout 30 bash -c "
-        while ! machinectl list --no-legend 2>/dev/null | grep >/dev/null '$machine'; do
-            if ! kill -0 $pid 2>/dev/null; then
-                echo 'vmspawn exited before machine registration'
-                cat '$log'
-                exit 77
-            fi
-            sleep .5
-        done
-    " || {
-        local rc=$?
-        if [[ $rc -eq 77 ]]; then exit 0; fi
-        exit "$rc"
-    }
-}
-
 # --- Boot the VM with one boot-time bind-volume ---
 MACHINE="test-bind-volume-$$"
 systemd-vmspawn \

test/units/TEST-87-AUX-UTILS-VM.replace-storage.sh

@@ -92,24 +92,6 @@ RUNTIME_VOL="test-replace-storage-runtime-$$"
 truncate -s 32M "$WORKDIR/new-backing-1.raw"
 truncate -s 32M "$WORKDIR/new-backing-2.raw"
 
-wait_for_machine() {
-    local machine="$1" pid="$2" log="$3"
-    timeout 30 bash -c "
-        while ! machinectl list --no-legend 2>/dev/null | grep >/dev/null '$machine'; do
-            if ! kill -0 $pid 2>/dev/null; then
-                echo 'vmspawn exited before machine registration'
-                cat '$log'
-                exit 77
-            fi
-            sleep .5
-        done
-    " || {
-        local rc=$?
-        if [[ $rc -eq 77 ]]; then exit 0; fi
-        exit "$rc"
-    }
-}
-
 MACHINE="test-replace-storage-$$"
 systemd-vmspawn \
     --machine="$MACHINE" \

test/units/TEST-87-AUX-UTILS-VM.vmspawn-drives.sh

@@ -83,20 +83,6 @@ mke2fs -t ext4 -q -d "$WORKDIR/rootfs" "$WORKDIR/root.raw"
 truncate -s 64M "$WORKDIR/extra1.raw"
 truncate -s 32M "$WORKDIR/extra2.raw"
 
-wait_for_machine() {
-    local machine="$1" pid="$2" log="$3"
-    timeout 30 bash -c "
-        while ! machinectl list --no-legend 2>/dev/null | grep >/dev/null '$machine'; do
-            if ! kill -0 $pid 2>/dev/null; then
-                echo 'vmspawn exited before machine registration'
-                cat '$log'
-                exit 1
-            fi
-            sleep .5
-        done
-    "
-}
-
 # --- Test 1: Multi-drive setup (root + 2 extra drives) ---
 # Verifies that --image with multiple --extra-drive flags works with the async
 # QMP pipeline. Three drives means three fdset allocations, three blockdev-add

test/units/TEST-87-AUX-UTILS-VM.vmspawn.sh

@@ -77,30 +77,6 @@ exec sleep infinity
 EOF
 chmod +x "$WORKDIR/root/sbin/init"
 
-# Wait for a vmspawn machine to register with machined.
-# Skips the test gracefully if vmspawn fails due to missing vhost-user-fs support (nested VM).
-wait_for_machine() {
-    local machine="$1" pid="$2" log="$3"
-    timeout 30 bash -c "
-        while ! machinectl list --no-legend 2>/dev/null | grep >/dev/null '$machine'; do
-            if ! kill -0 $pid 2>/dev/null; then
-                if grep >/dev/null 'virtiofs.*QMP\|vhost-user-fs-pci' '$log'; then
-                    echo 'vhost-user-fs not supported (nested VM?), skipping'
-                    exit 77
-                fi
-                echo 'vmspawn exited before registering'
-                cat '$log'
-                exit 1
-            fi
-            sleep .5
-        done
-    " || {
-        local rc=$?
-        if [[ $rc -eq 77 ]]; then exit 0; fi
-        exit "$rc"
-    }
-}
-
 # Launch vmspawn in the background with direct kernel boot and headless console.
 systemd-vmspawn \
     --machine="$MACHINE" \

test/units/util.sh

@@ -576,3 +576,28 @@ find_qemu_binary() {
 
     command -v "qemu-system-$arch" >/dev/null 2>&1
 }
+
+# Waits for a systemd-vmspawn machine to register with machined. If vmspawn bailed out because
+# vhost-user-fs isn't available (e.g. inside a nested VM) the test is skipped gracefully; any other
+# early vmspawn exit is treated as a failure. Args: machine name, vmspawn PID, vmspawn console log.
+wait_for_machine() {
+    local machine="$1" pid="$2" log="$3"
+    timeout 30 bash -c "
+        while ! machinectl list --no-legend 2>/dev/null | grep >/dev/null '$machine'; do
+            if ! kill -0 $pid 2>/dev/null; then
+                if grep >/dev/null 'virtiofs.*QMP\|vhost-user-fs-pci' '$log'; then
+                    echo 'vhost-user-fs not supported (nested VM?), skipping'
+                    exit 77
+                fi
+                echo 'vmspawn exited before registering'
+                cat '$log'
+                exit 1
+            fi
+            sleep .5
+        done
+    " || {
+        local rc=$?
+        if [[ $rc -eq 77 ]]; then exit 0; fi
+        exit "$rc"
+    }
+}