On Fri, Dec 01, 2017 at 01:58:32PM +0800, fangying wrote:
> QEMU will abort when vhost-user process is restarted during migration
> when vhost_log_global_start/stop is called. The reason is clear that
> vhost_dev_set_log returns -1 because network connection is lost.
>
> To handle this situation, let's cancel migration by setting migrate
> state to failure and report it to user.
In fact I don't see this as the right way to fix it. Backend is dead so why
not just proceed with migration? We just need to make sure we re-send
migration data on re-connect.
> ---
> hw/virtio/vhost.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index ddc42f0..92725f7 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -26,6 +26,8 @@
> #include "hw/virtio/virtio-bus.h"
> #include "hw/virtio/virtio-access.h"
> #include "migration/blocker.h"
> +#include "migration/migration.h"
> +#include "migration/qemu-file.h"
> #include "sysemu/dma.h"
>
> /* enabled until disconnected backend stabilizes */
> @@ -885,7 +887,10 @@ static void vhost_log_global_start(MemoryListener
> *listener)
>
> r = vhost_migration_log(listener, true);
> if (r < 0) {
> - abort();
> + error_report("Failed to start vhost dirty log");
> + if (migrate_get_current()->migration_thread_running) {
> + qemu_file_set_error(migrate_get_current()->to_dst_file, -ECHILD);
> + }
> }
> }
>
> @@ -895,7 +900,10 @@ static void vhost_log_global_stop(MemoryListener
> *listener)
>
> r = vhost_migration_log(listener, false);
> if (r < 0) {
> - abort();
> + error_report("Failed to stop vhost dirty log");
> + if (migrate_get_current()->migration_thread_running) {
> + qemu_file_set_error(migrate_get_current()->to_dst_file, -ECHILD);
> + }
> }
> }
>
> --
> 1.8.3.1
>
