Hi
----- Original Message -----
> On Sat, Sep 19, 2015 at 12:12:03PM +0200, marcandre.lur...@redhat.com wrote:
> > From: Marc-André Lureau <marcandre.lur...@redhat.com>
> >
> > Do not allocate a shared log if the backend doesn't support it.
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
>
> If not there, we probably want to block live migration, correct?
That make sense to me, I'll add that.
> > ---
> > hw/virtio/vhost-user.c | 9 +++++++++
> > hw/virtio/vhost.c | 15 ++++++++++-----
> > include/hw/virtio/vhost-backend.h | 4 ++++
> > 3 files changed, 23 insertions(+), 5 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index 3cb5559..d12cd66 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -508,10 +508,19 @@ static int vhost_user_cleanup(struct vhost_dev *dev)
> > return 0;
> > }
> >
> > +static bool vhost_user_want_shm_log(struct vhost_dev *dev)
> > +{
> > + assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
> > +
> > + return virtio_has_feature(dev->protocol_features,
> > + VHOST_USER_PROTOCOL_F_LOG_SHMFD);
> > +}
> > +
> > const VhostOps user_ops = {
> > .backend_type = VHOST_BACKEND_TYPE_USER,
> > .vhost_backend_init = vhost_user_init,
> > .vhost_backend_cleanup = vhost_user_cleanup,
> > + .vhost_backend_want_shm_log = vhost_user_want_shm_log,
> >
> > .vhost_net_set_backend = vhost_net_set_backend,
> > .vhost_scsi_set_endpoint = vhost_scsi_set_endpoint,
> > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> > index 0fa7b69..d5070fb 100644
> > --- a/hw/virtio/vhost.c
> > +++ b/hw/virtio/vhost.c
> > @@ -350,10 +350,15 @@ static void vhost_log_put(struct vhost_dev *dev, bool
> > sync)
> > }
> > }
> >
> > -static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t
> > size)
> > +static bool vhost_dev_log_is_shared(struct vhost_dev *dev)
> > {
> > - bool share = dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER;
> > - struct vhost_log *log = vhost_log_get(size, share);
> > + return dev->vhost_ops->vhost_backend_want_shm_log &&
> > + dev->vhost_ops->vhost_backend_want_shm_log(dev);
> > +}
> > +
> > +static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t
> > size)
> > +{
> > + struct vhost_log *log = vhost_log_get(size,
> > vhost_dev_log_is_shared(dev));
> > uint64_t log_base = (uintptr_t)log->log;
> > int r;
> >
> > @@ -1161,10 +1166,10 @@ int vhost_dev_start(struct vhost_dev *hdev,
> > VirtIODevice *vdev)
> >
> > if (hdev->log_enabled) {
> > uint64_t log_base;
> > - bool share = hdev->vhost_ops->backend_type ==
> > VHOST_BACKEND_TYPE_USER;
> >
> > hdev->log_size = vhost_get_log_size(hdev);
> > - hdev->log = vhost_log_get(hdev->log_size, share);
> > + hdev->log = vhost_log_get(hdev->log_size,
> > + vhost_dev_log_is_shared(hdev));
> > log_base = (uintptr_t)hdev->log->log;
> > r = hdev->vhost_ops->vhost_set_log_base(hdev,
> > hdev->log_size ? log_base
> > : 0,
> > diff --git a/include/hw/virtio/vhost-backend.h
> > b/include/hw/virtio/vhost-backend.h
> > index a87f0b3..44bf200 100644
> > --- a/include/hw/virtio/vhost-backend.h
> > +++ b/include/hw/virtio/vhost-backend.h
> > @@ -11,6 +11,8 @@
> > #ifndef VHOST_BACKEND_H_
> > #define VHOST_BACKEND_H_
> >
> > +#include <stdbool.h>
> > +
> > typedef enum VhostBackendType {
> > VHOST_BACKEND_TYPE_NONE = 0,
> > VHOST_BACKEND_TYPE_KERNEL = 1,
> > @@ -28,6 +30,7 @@ struct vhost_scsi_target;
> >
> > typedef int (*vhost_backend_init)(struct vhost_dev *dev, void *opaque);
> > typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev);
> > +typedef bool (*vhost_backend_want_shm_log)(struct vhost_dev *dev);
> >
> > typedef int (*vhost_net_set_backend_op)(struct vhost_dev *dev,
> > struct vhost_vring_file *file);
> > @@ -67,6 +70,7 @@ typedef struct VhostOps {
> >
> > vhost_backend_init vhost_backend_init;
> > vhost_backend_cleanup vhost_backend_cleanup;
> > + vhost_backend_want_shm_log vhost_backend_want_shm_log;
> >
> > vhost_net_set_backend_op vhost_net_set_backend;
> > vhost_scsi_set_endpoint_op vhost_scsi_set_endpoint;
> > --
> > 2.4.3
>
