gwj / at91sam9263 · Commits

Commit 8a43b1ea7fd02a8e9a5c5ef58017b1bd059663bb

Authored by Chris Lalancette
Committed by Anthony Liguori
1 parent c16b5a2c

Allow monitor interaction when using migrate -exec 

All,
     I've recently been playing around with migration via exec.  Unfortunately,
when starting the incoming qemu process with "-incoming exec:cmd", it suffers
the same problem that -incoming tcp used to suffer; namely, that you can't
interact with the monitor until after the migration has happened.  This causes
problems for libvirt usage of -incoming exec, since libvirt expects to be able
to access the monitor ahead of time.  This fairly simple patch allows you to
access the monitor both before and after the migration has completed using exec.

(note: developed/tested with qemu-kvm, but applies perfectly fine to qemu)

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Inline Side-by-side
Showing 3 changed files with 34 additions and 12 deletions
... ... @@ -51,6 +51,7 @@ QEMUFile *qemu_fopen(const char *filename, const char *mode);
51 51 QEMUFile *qemu_fopen_socket(int fd);
52 52 QEMUFile *qemu_popen(FILE *popen_file, const char *mode);
53 53 QEMUFile *qemu_popen_cmd(const char *command, const char *mode);
  54 +int qemu_popen_fd(QEMUFile *f);
54 55 void qemu_fflush(QEMUFile *f);
55 56 int qemu_fclose(QEMUFile *f);
56 57 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size);
... ...
migration-exec.c
  View file @8a43b1e
... ... @@ -104,17 +104,11 @@ err_after_alloc:
104 104 return NULL;
105 105 }
106 106  
107   -int exec_start_incoming_migration(const char *command)
  107 +static void exec_accept_incoming_migration(void *opaque)
108 108 {
  109 + QEMUFile *f = opaque;
109 110 int ret;
110   - QEMUFile *f;
111 111  
112   - dprintf("Attempting to start an incoming migration\n");
113   - f = qemu_popen_cmd(command, "r");
114   - if(f == NULL) {
115   - dprintf("Unable to apply qemu wrapper to popen file\n");
116   - return -errno;
117   - }
118 112 vm_stop(0); /* just in case */
119 113 ret = qemu_loadvm_state(f);
120 114 if (ret < 0) {
... ... @@ -123,11 +117,28 @@ int exec_start_incoming_migration(const char *command)
123 117 }
124 118 qemu_announce_self();
125 119 dprintf("successfully loaded vm state\n");
  120 + /* we've successfully migrated, close the fd */
  121 + qemu_set_fd_handler2(qemu_popen_fd(f), NULL, NULL, NULL, NULL);
126 122 vm_start();
127   - qemu_fclose(f);
128   - return 0;
129 123  
130 124 err:
131 125 qemu_fclose(f);
132   - return -errno;
  126 +}
  127 +
  128 +int exec_start_incoming_migration(const char *command)
  129 +{
  130 + QEMUFile *f;
  131 +
  132 + dprintf("Attempting to start an incoming migration\n");
  133 + f = qemu_popen_cmd(command, "r");
  134 + if(f == NULL) {
  135 + dprintf("Unable to apply qemu wrapper to popen file\n");
  136 + return -errno;
  137 + }
  138 +
  139 + qemu_set_fd_handler2(qemu_popen_fd(f), NULL,
  140 + exec_accept_incoming_migration, NULL,
  141 + (void *)(unsigned long)f);
  142 +
  143 + return 0;
133 144 }
... ...
savevm.c
  View file @8a43b1e
... ... @@ -244,7 +244,6 @@ QEMUFile *qemu_popen(FILE *popen_file, const char *mode)
244 244 } else {
245 245 s->file = qemu_fopen_ops(s, popen_put_buffer, NULL, popen_close, NULL, NULL);
246 246 }
247   - fprintf(stderr, "qemu_popen: returning result of qemu_fopen_ops\n");
248 247 return s->file;
249 248 }
250 249  
... ... @@ -260,6 +259,17 @@ QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
260 259 return qemu_popen(popen_file, mode);
261 260 }
262 261  
  262 +int qemu_popen_fd(QEMUFile *f)
  263 +{
  264 + QEMUFilePopen *p;
  265 + int fd;
  266 +
  267 + p = (QEMUFilePopen *)f->opaque;
  268 + fd = fileno(p->popen_file);
  269 +
  270 + return fd;
  271 +}
  272 +
263 273 QEMUFile *qemu_fopen_socket(int fd)
264 274 {
265 275 QEMUFileSocket *s = qemu_mallocz(sizeof(QEMUFileSocket));
... ...