tests/qtest/migration: Move ufd_version_check to utils

Move ufd_version_check() to migration-util.c file. This is a helper
function that is used during tests definition so it should be
available outside of migration-test.c

Since the function is moving to another file, change it to stop
accessing the global uffd_feature_thread_id and take it as argument
instead.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>

tests/qtest/migration-test.c

@@ -35,6 +35,7 @@
 /* For dirty ring test; so far only x86_64 is supported */
 #if defined(__linux__) && defined(HOST_X86_64)
 #include "linux/kvm.h"
+#include <sys/ioctl.h>
 #endif
 
 unsigned start_address;
@@ -88,50 +89,6 @@ typedef enum PostcopyRecoveryFailStage {
 #include <sys/vfs.h>
 #endif
 
-#if defined(__linux__) && defined(__NR_userfaultfd) && defined(CONFIG_EVENTFD)
-#include <sys/eventfd.h>
-#include <sys/ioctl.h>
-#include "qemu/userfaultfd.h"
-
-static bool ufd_version_check(void)
-{
-    struct uffdio_api api_struct;
-    uint64_t ioctl_mask;
-
-    int ufd = uffd_open(O_CLOEXEC);
-
-    if (ufd == -1) {
-        g_test_message("Skipping test: userfaultfd not available");
-        return false;
-    }
-
-    api_struct.api = UFFD_API;
-    api_struct.features = 0;
-    if (ioctl(ufd, UFFDIO_API, &api_struct)) {
-        g_test_message("Skipping test: UFFDIO_API failed");
-        return false;
-    }
-    uffd_feature_thread_id = api_struct.features & UFFD_FEATURE_THREAD_ID;
-
-    ioctl_mask = (1ULL << _UFFDIO_REGISTER |
-                  1ULL << _UFFDIO_UNREGISTER);
-    if ((api_struct.ioctls & ioctl_mask) != ioctl_mask) {
-        g_test_message("Skipping test: Missing userfault feature");
-        return false;
-    }
-
-    return true;
-}
-
-#else
-static bool ufd_version_check(void)
-{
-    g_test_message("Skipping test: Userfault not available (builtdtime)");
-    return false;
-}
-
-#endif
-
 static char *tmpfs;
 static char *bootpath;
 
@@ -3532,7 +3489,7 @@ int main(int argc, char **argv)
         return 0;
     }
 
-    has_uffd = ufd_version_check();
+    has_uffd = ufd_version_check(&uffd_feature_thread_id);
     arch = qtest_get_arch();
     is_x86 = !strcmp(arch, "i386") || !strcmp(arch, "x86_64");
 

tests/qtest/migration/migration-util.c

@@ -22,6 +22,13 @@
 #include "migration/bootfile.h"
 #include "migration/migration-util.h"
 
+/* for uffd_version_check() */
+#if defined(__linux__) && defined(__NR_userfaultfd) && defined(CONFIG_EVENTFD)
+#include <sys/eventfd.h>
+#include "qemu/userfaultfd.h"
+#endif
+
+
 static char *SocketAddress_to_str(SocketAddress *addr)
 {
     switch (addr->type) {
@@ -283,3 +290,44 @@ bool probe_o_direct_support(const char *tmpfs)
     return true;
 }
 #endif
+
+#if defined(__linux__) && defined(__NR_userfaultfd) && defined(CONFIG_EVENTFD)
+bool ufd_version_check(bool *uffd_feature_thread_id)
+{
+    struct uffdio_api api_struct;
+    uint64_t ioctl_mask;
+
+    int ufd = uffd_open(O_CLOEXEC);
+
+    if (ufd == -1) {
+        g_test_message("Skipping test: userfaultfd not available");
+        return false;
+    }
+
+    api_struct.api = UFFD_API;
+    api_struct.features = 0;
+    if (ioctl(ufd, UFFDIO_API, &api_struct)) {
+        g_test_message("Skipping test: UFFDIO_API failed");
+        return false;
+    }
+
+    if (uffd_feature_thread_id) {
+        *uffd_feature_thread_id = api_struct.features & UFFD_FEATURE_THREAD_ID;
+    }
+
+    ioctl_mask = (1ULL << _UFFDIO_REGISTER |
+                  1ULL << _UFFDIO_UNREGISTER);
+    if ((api_struct.ioctls & ioctl_mask) != ioctl_mask) {
+        g_test_message("Skipping test: Missing userfault feature");
+        return false;
+    }
+
+    return true;
+}
+#else
+bool ufd_version_check(bool *uffd_feature_thread_id)
+{
+    g_test_message("Skipping test: Userfault not available (builtdtime)");
+    return false;
+}
+#endif

tests/qtest/migration/migration-util.h

@@ -47,6 +47,8 @@ static inline bool probe_o_direct_support(const char *tmpfs)
     return false;
 }
 #endif
+
+bool ufd_version_check(bool *uffd_feature_thread_id);
 void migration_test_add(const char *path, void (*fn)(void));
 char *migrate_get_connect_uri(QTestState *who);
 void migrate_set_ports(QTestState *to, QList *channel_list);