On Fri, Aug 27, 2021 at 01:53:22PM -0400, Jagannathan Raman wrote:
> create a context with the vfio-user library to run a PCI device
> 
> Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
> Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
> ---
>  hw/remote/vfio-user-obj.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
> index 4a1e297..99d3dd1 100644
> --- a/hw/remote/vfio-user-obj.c
> +++ b/hw/remote/vfio-user-obj.c
> @@ -27,11 +27,17 @@
>  #include "qemu/osdep.h"
>  #include "qemu-common.h"
>  
> +#include <errno.h>

qemu/osdep.h already includes <errno.h>

> +
>  #include "qom/object.h"
>  #include "qom/object_interfaces.h"
>  #include "qemu/error-report.h"
>  #include "trace.h"
>  #include "sysemu/runstate.h"
> +#include "qemu/notify.h"
> +#include "qapi/error.h"
> +#include "sysemu/sysemu.h"
> +#include "libvfio-user.h"
>  
>  #define TYPE_VFU_OBJECT "vfio-user"
>  OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
> @@ -51,6 +57,10 @@ struct VfuObject {
>  
>      char *socket;
>      char *devid;
> +
> +    Notifier machine_done;
> +
> +    vfu_ctx_t *vfu_ctx;
>  };
>  
>  static void vfu_object_set_socket(Object *obj, const char *str, Error **errp)
> @@ -75,9 +85,23 @@ static void vfu_object_set_devid(Object *obj, const char *str, Error **errp)
>      trace_vfu_prop("devid", str);
>  }
>  
> +static void vfu_object_machine_done(Notifier *notifier, void *data)

Please document the reason for using a machine init done notifier.

> +{
> +    VfuObject *o = container_of(notifier, VfuObject, machine_done);
> +
> +    o->vfu_ctx = vfu_create_ctx(VFU_TRANS_SOCK, o->socket, 0,
> +                                o, VFU_DEV_TYPE_PCI);
> +    if (o->vfu_ctx == NULL) {
> +        error_setg(&error_abort, "vfu: Failed to create context - %s",
> +                   strerror(errno));
> +        return;
> +    }
> +}
> +
>  static void vfu_object_init(Object *obj)
>  {
>      VfuObjectClass *k = VFU_OBJECT_GET_CLASS(obj);
> +    VfuObject *o = VFU_OBJECT(obj);
>  
>      if (!object_dynamic_cast(OBJECT(current_machine), TYPE_REMOTE_MACHINE)) {
>          error_report("vfu: %s only compatible with %s machine",
> @@ -92,6 +116,9 @@ static void vfu_object_init(Object *obj)
>      }
>  
>      k->nr_devs++;
> +
> +    o->machine_done.notify = vfu_object_machine_done;
> +    qemu_add_machine_init_done_notifier(&o->machine_done);
>  }
>  
>  static void vfu_object_finalize(Object *obj)
> @@ -101,6 +128,8 @@ static void vfu_object_finalize(Object *obj)
>  
>      k->nr_devs--;
>  
> +    vfu_destroy_ctx(o->vfu_ctx);

Will this function ever be called before vfu_object_machine_done() is
called? In that case vfu_ctx isn't initialized.