* Peter Xu (peterx@redhat.com) wrote:
> Introducing this new command to be sent when the source VM is ready to
> resume the paused migration. What the destination does here is
> basically release the fault thread to continue service page faults.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> migration/savevm.c | 33 +++++++++++++++++++++++++++++++++
> migration/savevm.h | 1 +
> migration/trace-events | 1 +
> 3 files changed, 35 insertions(+)
>
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 7f77a31..e914346 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -77,6 +77,7 @@ enum qemu_vm_cmd {
> MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
> were previously sent during
> precopy but are dirty. */
> + MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */
> MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */
> MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */
> MIG_CMD_MAX
> @@ -95,6 +96,7 @@ static struct mig_cmd_args {
> [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
> [MIG_CMD_POSTCOPY_RAM_DISCARD] = {
> .len = -1, .name = "POSTCOPY_RAM_DISCARD" },
> + [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" },
> [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" },
> [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
> [MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
> @@ -931,6 +933,12 @@ void qemu_savevm_send_postcopy_run(QEMUFile *f)
> qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
> }
>
> +void qemu_savevm_send_postcopy_resume(QEMUFile *f)
> +{
> + trace_savevm_send_postcopy_resume();
> + qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL);
> +}
> +
> void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name)
> {
> size_t len;
> @@ -1682,6 +1690,28 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
> return LOADVM_QUIT;
> }
>
> +static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
> +{
> + if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
> + error_report("%s: illegal resume received", __func__);
> + /* Don't fail the load, only for this. */
> + return 0;
> + }
> +
> + /*
> + * This means source VM is ready to resume the postcopy migration.
> + * It's time to switch state and release the fault thread to
> + * continue service page faults.
> + */
> + migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
> + MIGRATION_STATUS_POSTCOPY_ACTIVE);
> + qemu_sem_post(&mis->postcopy_pause_sem_fault);
> +
> + /* TODO: Tell source that "we are ready" */
> +
You might want to add a trace in here; however,
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> + return 0;
> +}
> +
> /**
> * Immediately following this command is a blob of data containing an embedded
> * chunk of migration stream; read it and load it.
> @@ -1847,6 +1877,9 @@ static int loadvm_process_command(QEMUFile *f)
> case MIG_CMD_POSTCOPY_RAM_DISCARD:
> return loadvm_postcopy_ram_handle_discard(mis, len);
>
> + case MIG_CMD_POSTCOPY_RESUME:
> + return loadvm_postcopy_handle_resume(mis);
> +
> case MIG_CMD_RECV_BITMAP:
> return loadvm_handle_recv_bitmap(mis, len);
> }
> diff --git a/migration/savevm.h b/migration/savevm.h
> index 8126b1c..a5f3879 100644
> --- a/migration/savevm.h
> +++ b/migration/savevm.h
> @@ -46,6 +46,7 @@ int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len);
> void qemu_savevm_send_postcopy_advise(QEMUFile *f);
> void qemu_savevm_send_postcopy_listen(QEMUFile *f);
> void qemu_savevm_send_postcopy_run(QEMUFile *f);
> +void qemu_savevm_send_postcopy_resume(QEMUFile *f);
> void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name);
>
> void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
> diff --git a/migration/trace-events b/migration/trace-events
> index 9960cd8..0a1c302 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -35,6 +35,7 @@ savevm_send_open_return_path(void) ""
> savevm_send_ping(uint32_t val) "0x%x"
> savevm_send_postcopy_listen(void) ""
> savevm_send_postcopy_run(void) ""
> +savevm_send_postcopy_resume(void) ""
> savevm_send_recv_bitmap(char *name) "%s"
> savevm_state_setup(void) ""
> savevm_state_header(void) ""
> --
> 2.7.4
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK