Re: [RFC v3 6/8] vhost-backend: export the vhost backend helper

[Cindy Lu]

On Tue, Jun 16, 2020 at 4:17 PM Laurent Vivier <lvivier@redhat.com> wrote:
>
> On 29/05/2020 16:06, Cindy Lu wrote:
> > export the helper then we can reuse some of them in vhost-vdpa
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >  hw/virtio/vhost-backend.c         | 34 ++++++++++++++++++-------------
> >  include/hw/virtio/vhost-backend.h | 28 +++++++++++++++++++++++++
> >  2 files changed, 48 insertions(+), 14 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> > index 48905383f8..42efb4967b 100644
> > --- a/hw/virtio/vhost-backend.c
> > +++ b/hw/virtio/vhost-backend.c
> > @@ -14,7 +14,7 @@
> >  #include "qemu/error-report.h"
> >  #include "qemu/main-loop.h"
> >  #include "standard-headers/linux/vhost_types.h"
> > -
> > +#include "hw/virtio/vhost-vdpa.h"
>
> You can't include this file because it is created in the next patch.
>
> >  #ifdef CONFIG_VHOST_KERNEL
> >  #include <linux/vhost.h>
> >  #include <sys/ioctl.h>
> > @@ -22,10 +22,16 @@
> >  static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int 
> > request,
> >                               void *arg)
> >  {
> > -    int fd = (uintptr_t) dev->opaque;
> > -
> > -    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
> > -
> > +    int fd = -1;
> > +    struct vhost_vdpa *v = NULL;
> > +    if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL) {
> > +        fd  = (uintptr_t) dev->opaque;
> > +    }
> > +    if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> > +        v = dev->opaque;
> > +        fd = v->device_fd;
> > +    }
> > +    assert(fd != -1);
>
> A switch would be cleaner:
>
>     switch (dev->vhost_ops->backend_type) {
>     case VHOST_BACKEND_TYPE_KERNEL:
>         fd  = (uintptr_t)dev->opaque;
>         break;
>     case VHOST_BACKEND_TYPE_VDPA:
>         fd = ((struct vhost_vdpa *)dev->opaque)->device_fd;
>         break;
>     default:
>         g_assert_not_reached()
>     }
>
> >      return ioctl(fd, request, arg);
> >  }
> >
>
Thanks Laurent , will fix this
> Thanks,
> Laurent
>