diff options
Diffstat (limited to 'tools/xcutils')
| -rw-r--r-- | tools/xcutils/xc_save.c | 78 |
1 files changed, 47 insertions, 31 deletions
diff --git a/tools/xcutils/xc_save.c b/tools/xcutils/xc_save.c index 3dfc03117a..c8b0ccb05c 100644 --- a/tools/xcutils/xc_save.c +++ b/tools/xcutils/xc_save.c @@ -46,17 +46,36 @@ static int compat_suspend(void) static int suspend_evtchn_release(void) { if (si.suspend_evtchn >= 0) { - xc_evtchn_unbind(si.xce, si.suspend_evtchn); - si.suspend_evtchn = -1; + xc_evtchn_unbind(si.xce, si.suspend_evtchn); + si.suspend_evtchn = -1; } if (si.xce >= 0) { - xc_evtchn_close(si.xce); - si.xce = -1; + xc_evtchn_close(si.xce); + si.xce = -1; } return 0; } +static int await_suspend(void) +{ + int rc; + + do { + rc = xc_evtchn_pending(si.xce); + if (rc < 0) { + warnx("error polling suspend notification channel: %d", rc); + return -1; + } + } while (rc != si.suspend_evtchn); + + /* harmless for one-off suspend */ + if (xc_evtchn_unmask(si.xce, si.suspend_evtchn) < 0) + warnx("failed to unmask suspend notification channel: %d", rc); + + return 0; +} + static int suspend_evtchn_init(int xc, int domid) { struct xs_handle *xs; @@ -71,16 +90,16 @@ static int suspend_evtchn_init(int xc, int domid) xs = xs_daemon_open(); if (!xs) { - warnx("failed to get xenstore handle"); - return -1; + warnx("failed to get xenstore handle"); + return -1; } sprintf(path, "/local/domain/%d/device/suspend/event-channel", domid); portstr = xs_read(xs, XBT_NULL, path, &plen); xs_daemon_close(xs); if (!portstr || !plen) { - warnx("could not read suspend event channel"); - return -1; + warnx("could not read suspend event channel"); + return -1; } port = atoi(portstr); @@ -88,22 +107,25 @@ static int suspend_evtchn_init(int xc, int domid) si.xce = xc_evtchn_open(); if (si.xce < 0) { - warnx("failed to open event channel handle"); - goto cleanup; + warnx("failed to open event channel handle"); + goto cleanup; } si.suspend_evtchn = xc_evtchn_bind_interdomain(si.xce, domid, port); if (si.suspend_evtchn < 0) { - warnx("failed to bind suspend event channel: %d", si.suspend_evtchn); - goto cleanup; + warnx("failed to bind suspend event channel: %d", si.suspend_evtchn); + goto cleanup; } rc = xc_domain_subscribe_for_suspend(xc, domid, port); if (rc < 0) { - warnx("failed to subscribe to domain: %d", rc); - goto cleanup; + warnx("failed to subscribe to domain: %d", rc); + goto cleanup; } + /* event channel is pending immediately after binding */ + await_suspend(); + return 0; cleanup: @@ -121,21 +143,14 @@ static int evtchn_suspend(void) rc = xc_evtchn_notify(si.xce, si.suspend_evtchn); if (rc < 0) { - warnx("failed to notify suspend request channel: %d", rc); - return 0; + warnx("failed to notify suspend request channel: %d", rc); + return 0; } - do { - rc = xc_evtchn_pending(si.xce); - if (rc < 0) { - warnx("error polling suspend notification channel: %d", rc); - return 0; - } - } while (rc != si.suspend_evtchn); - - /* harmless for one-off suspend */ - if (xc_evtchn_unmask(si.xce, si.suspend_evtchn) < 0) - warnx("failed to unmask suspend notification channel: %d", rc); + if (await_suspend() < 0) { + warnx("suspend failed"); + return 0; + } /* notify xend that it can do device migration */ printf("suspended\n"); @@ -147,7 +162,7 @@ static int evtchn_suspend(void) static int suspend(void) { if (si.suspend_evtchn >= 0) - return evtchn_suspend(); + return evtchn_suspend(); return compat_suspend(); } @@ -194,7 +209,7 @@ static void qemu_flip_buffer(int domid, int next_active) * other buffer */ if (!xs_write(xs, XBT_NULL, qemu_next_active_path, &digit, 1)) errx(1, "can't write next-active to store path (%s)\n", - qemu_next_active_path); + qemu_next_active_path); /* Wait a while for qemu to signal that it has switched to the new * active buffer */ @@ -286,7 +301,7 @@ main(int argc, char **argv) int ret; if (argc != 6) - errx(1, "usage: %s iofd domid maxit maxf flags", argv[0]); + errx(1, "usage: %s iofd domid maxit maxf flags", argv[0]); xc_fd = xc_interface_open(); if (xc_fd < 0) @@ -298,7 +313,8 @@ main(int argc, char **argv) max_f = atoi(argv[4]); flags = atoi(argv[5]); - suspend_evtchn_init(xc_fd, domid); + if (suspend_evtchn_init(xc_fd, domid) < 0) + warnx("suspend event channel initialization failed, using slow path"); ret = xc_domain_save(xc_fd, io_fd, domid, maxit, max_f, flags, &suspend, !!(flags & XCFLAGS_HVM), |