On Mon, May 23, 2022 at 10:28 AM Stefano Garzarella <sgarzare@xxxxxxxxxx> wrote: > > On Fri, May 20, 2022 at 07:23:25PM +0200, Eugenio Pérez wrote: > >Implement stop operation for vdpa_sim devices, so vhost-vdpa will offer > >that backend feature and userspace can effectively stop the device. > > > >This is a must before get virtqueue indexes (base) for live migration, > >since the device could modify them after userland gets them. There are > >individual ways to perform that action for some devices > >(VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING, ...) but there was no > >way to perform it for any vhost device (and, in particular, vhost-vdpa). > > > >Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx> > >--- > > drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++++++ > > drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 + > > drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 3 +++ > > 3 files changed, 25 insertions(+) > > > >diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c > >index 50d721072beb..0515cf314bed 100644 > >--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c > >+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c > >@@ -107,6 +107,7 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim) > > for (i = 0; i < vdpasim->dev_attr.nas; i++) > > vhost_iotlb_reset(&vdpasim->iommu[i]); > > > >+ vdpasim->running = true; > > spin_unlock(&vdpasim->iommu_lock); > > > > vdpasim->features = 0; > >@@ -505,6 +506,24 @@ static int vdpasim_reset(struct vdpa_device *vdpa) > > return 0; > > } > > > >+static int vdpasim_stop(struct vdpa_device *vdpa, bool stop) > >+{ > >+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > >+ int i; > >+ > >+ spin_lock(&vdpasim->lock); > >+ vdpasim->running = !stop; > >+ if (vdpasim->running) { > >+ /* Check for missed buffers */ > >+ for (i = 0; i < vdpasim->dev_attr.nvqs; ++i) > >+ vdpasim_kick_vq(vdpa, i); > >+ > >+ } > >+ spin_unlock(&vdpasim->lock); > >+ > >+ return 0; > >+} > >+ > > static size_t vdpasim_get_config_size(struct vdpa_device *vdpa) > > { > > struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > >@@ -694,6 +713,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = { > > .get_status = vdpasim_get_status, > > .set_status = vdpasim_set_status, > > .reset = vdpasim_reset, > >+ .stop = vdpasim_stop, > > .get_config_size = vdpasim_get_config_size, > > .get_config = vdpasim_get_config, > > .set_config = vdpasim_set_config, > >@@ -726,6 +746,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = { > > .get_status = vdpasim_get_status, > > .set_status = vdpasim_set_status, > > .reset = vdpasim_reset, > >+ .stop = vdpasim_stop, > > .get_config_size = vdpasim_get_config_size, > > .get_config = vdpasim_get_config, > > .set_config = vdpasim_set_config, > >diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h > >index 622782e92239..061986f30911 100644 > >--- a/drivers/vdpa/vdpa_sim/vdpa_sim.h > >+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h > >@@ -66,6 +66,7 @@ struct vdpasim { > > u32 generation; > > u64 features; > > u32 groups; > >+ bool running; > > /* spinlock to synchronize iommu table */ > > spinlock_t iommu_lock; > > }; > >diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c > >index 5125976a4df8..886449e88502 100644 > >--- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c > >+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c > >@@ -154,6 +154,9 @@ static void vdpasim_net_work(struct work_struct *work) > > > > spin_lock(&vdpasim->lock); > > > >+ if (!vdpasim->running) > >+ goto out; > >+ > > It would be nice to do the same for vdpa_sim_blk as well. > Agree, it will be added in the next revision. If not, blk presents an invalid backend feature bit. Thanks! > Thanks, > Stefano >