Re: [Qemu-devel] [PATCH v4 2/4] migration: Allow "device add" options to only add migratable devices

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Ashijeet Acharya (ashijeetacharya@gmail.com) wrote:
> Introduce checks for the unmigratable flag in the VMStateDescription
> structs of respective devices when user attempts to add them. If the
> "--only-migratable" was specified, all unmigratable devices will
> rightly fail to add. This feature is made compatible for both "-device"
> and "-usbdevice" command line options and covers their hmp and qmp
> counterparts as well.
> 
> Signed-off-by: Ashijeet Acharya <ashijeetacharya@gmail.com>
> ---
>  hw/usb/bus.c   | 18 ++++++++++++++++++
>  qdev-monitor.c |  9 +++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/hw/usb/bus.c b/hw/usb/bus.c
> index 25913ad..3d26103 100644
> --- a/hw/usb/bus.c
> +++ b/hw/usb/bus.c
> @@ -8,6 +8,7 @@
>  #include "monitor/monitor.h"
>  #include "trace.h"
>  #include "qemu/cutils.h"
> +#include "migration/migration.h"
>  
>  static void usb_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
>  
> @@ -686,6 +687,8 @@ USBDevice *usbdevice_create(const char *cmdline)
>      const char *params;
>      int len;
>      USBDevice *dev;
> +    ObjectClass *klass;
> +    DeviceClass *dc;
>  
>      params = strchr(cmdline,':');
>      if (params) {
> @@ -720,6 +723,21 @@ USBDevice *usbdevice_create(const char *cmdline)
>          return NULL;
>      }
>  
> +    klass = object_class_by_name(f->name);
> +    if (klass == NULL) {
> +        return NULL;

All error paths should print something, even if it shouldn't happen.

Dave

> +    }
> +
> +    dc = DEVICE_CLASS(klass);
> +
> +    if (only_migratable) {
> +        if (dc->vmsd->unmigratable) {
> +            error_report("Device %s is not migratable, but --only-migratable "
> +                         "was specified", f->name);
> +            return NULL;
> +        }
> +    }
> +
>      if (f->usbdevice_init) {
>          dev = f->usbdevice_init(bus, params);
>      } else {
> diff --git a/qdev-monitor.c b/qdev-monitor.c
> index c73410c..81d01df 100644
> --- a/qdev-monitor.c
> +++ b/qdev-monitor.c
> @@ -29,6 +29,7 @@
>  #include "qemu/error-report.h"
>  #include "qemu/help_option.h"
>  #include "sysemu/block-backend.h"
> +#include "migration/migration.h"
>  
>  /*
>   * Aliases were a bad idea from the start.  Let's keep them
> @@ -577,6 +578,14 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
>          return NULL;
>      }
>  
> +    if (only_migratable) {
> +        if (dc->vmsd->unmigratable) {
> +            error_setg(errp, "Device %s is not migratable, but "
> +                       "--only-migratable was specified", driver);
> +            return NULL;
> +        }
> +    }
> +
>      /* find bus */
>      path = qemu_opt_get(opts, "bus");
>      if (path != NULL) {
> -- 
> 2.6.2
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK