Jason Wang
2023-Feb-27 08:08 UTC
[PATCH v4 09/15] vdpa: add vdpa net migration state notifier
? 2023/2/24 23:54, Eugenio P?rez ??:> This allows net to restart the device backend to configure SVQ on it. > > Ideally, these changes should not be net specific. However, the vdpa net > backend is the one with enough knowledge to configure everything because > of some reasons: > * Queues might need to be shadowed or not depending on its kind (control > vs data). > * Queues need to share the same map translations (iova tree). > > Because of that it is cleaner to restart the whole net backend and > configure again as expected, similar to how vhost-kernel moves between > userspace and passthrough. > > If more kinds of devices need dynamic switching to SVQ we can create a > callback struct like VhostOps and move most of the code there. > VhostOps cannot be reused since all vdpa backend share them, and to > personalize just for networking would be too heavy. > > Signed-off-by: Eugenio P?rez <eperezma at redhat.com> > --- > v4: > * Delete duplication of set shadow_data and shadow_vqs_enabled moving it > to data / cvq net start functions. > > v3: > * Check for migration state at vdpa device start to enable SVQ in data > vqs. > > v1 from RFC: > * Add TODO to use the resume operation in the future. > * Use migration_in_setup and migration_has_failed instead of a > complicated switch case. > --- > net/vhost-vdpa.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 69 insertions(+), 3 deletions(-) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index b89c99066a..c5512ddf10 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -26,12 +26,15 @@ > #include <err.h> > #include "standard-headers/linux/virtio_net.h" > #include "monitor/monitor.h" > +#include "migration/migration.h" > +#include "migration/misc.h" > #include "hw/virtio/vhost.h" > > /* Todo:need to add the multiqueue support here */ > typedef struct VhostVDPAState { > NetClientState nc; > struct vhost_vdpa vhost_vdpa; > + Notifier migration_state; > VHostNetState *vhost_net; > > /* Control commands shadow buffers */ > @@ -239,10 +242,59 @@ static VhostVDPAState *vhost_vdpa_net_first_nc_vdpa(VhostVDPAState *s) > return DO_UPCAST(VhostVDPAState, nc, nc0); > } > > +static void vhost_vdpa_net_log_global_enable(VhostVDPAState *s, bool enable) > +{ > + struct vhost_vdpa *v = &s->vhost_vdpa; > + VirtIONet *n; > + VirtIODevice *vdev; > + int data_queue_pairs, cvq, r; > + > + /* We are only called on the first data vqs and only if x-svq is not set */ > + if (s->vhost_vdpa.shadow_vqs_enabled == enable) { > + return; > + } > + > + vdev = v->dev->vdev; > + n = VIRTIO_NET(vdev); > + if (!n->vhost_started) { > + return; > + } > + > + data_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1; > + cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ? > + n->max_ncs - n->max_queue_pairs : 0; > + /* > + * TODO: vhost_net_stop does suspend, get_base and reset. We can be smarter > + * in the future and resume the device if read-only operations between > + * suspend and reset goes wrong. > + */ > + vhost_net_stop(vdev, n->nic->ncs, data_queue_pairs, cvq); > + > + /* Start will check migration setup_or_active to configure or not SVQ */ > + r = vhost_net_start(vdev, n->nic->ncs, data_queue_pairs, cvq); > + if (unlikely(r < 0)) { > + error_report("unable to start vhost net: %s(%d)", g_strerror(-r), -r); > + } > +} > + > +static void vdpa_net_migration_state_notifier(Notifier *notifier, void *data) > +{ > + MigrationState *migration = data; > + VhostVDPAState *s = container_of(notifier, VhostVDPAState, > + migration_state); > + > + if (migration_in_setup(migration)) { > + vhost_vdpa_net_log_global_enable(s, true); > + } else if (migration_has_failed(migration)) { > + vhost_vdpa_net_log_global_enable(s, false); > + } > +} > + > static void vhost_vdpa_net_data_start_first(VhostVDPAState *s) > { > struct vhost_vdpa *v = &s->vhost_vdpa; > > + add_migration_state_change_notifier(&s->migration_state); > if (v->shadow_vqs_enabled) { > v->iova_tree = vhost_iova_tree_new(v->iova_range.first, > v->iova_range.last); > @@ -256,6 +308,15 @@ static int vhost_vdpa_net_data_start(NetClientState *nc) > > assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); > > + if (s->always_svq || > + migration_is_setup_or_active(migrate_get_current()->state)) { > + v->shadow_vqs_enabled = true; > + v->shadow_data = true; > + } else { > + v->shadow_vqs_enabled = false; > + v->shadow_data = false; > + } > + > if (v->index == 0) { > vhost_vdpa_net_data_start_first(s); > return 0; > @@ -276,6 +337,10 @@ static void vhost_vdpa_net_client_stop(NetClientState *nc) > > assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); > > + if (s->vhost_vdpa.index == 0) { > + remove_migration_state_change_notifier(&s->migration_state); > + }This should work but I just realize that vhost support vhost_dev_set_log(), I wonder if it would be simpler to go with that way. Using vhost_virtqueue_set_addr(, enable_log = true)? Thanks> + > dev = s->vhost_vdpa.dev; > if (dev->vq_index + dev->nvqs == dev->vq_index_end) { > g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete); > @@ -412,11 +477,12 @@ static int vhost_vdpa_net_cvq_start(NetClientState *nc) > s = DO_UPCAST(VhostVDPAState, nc, nc); > v = &s->vhost_vdpa; > > - v->shadow_data = s->always_svq; > + s0 = vhost_vdpa_net_first_nc_vdpa(s); > + v->shadow_data = s0->vhost_vdpa.shadow_vqs_enabled; > v->shadow_vqs_enabled = s->always_svq; > s->vhost_vdpa.address_space_id = VHOST_VDPA_GUEST_PA_ASID; > > - if (s->always_svq) { > + if (s->vhost_vdpa.shadow_data) { > /* SVQ is already configured for all virtqueues */ > goto out; > } > @@ -473,7 +539,6 @@ out: > return 0; > } > > - s0 = vhost_vdpa_net_first_nc_vdpa(s); > if (s0->vhost_vdpa.iova_tree) { > /* > * SVQ is already configured for all virtqueues. Reuse IOVA tree for > @@ -749,6 +814,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, > s->vhost_vdpa.device_fd = vdpa_device_fd; > s->vhost_vdpa.index = queue_pair_index; > s->always_svq = svq; > + s->migration_state.notify = vdpa_net_migration_state_notifier; > s->vhost_vdpa.shadow_vqs_enabled = svq; > s->vhost_vdpa.iova_range = iova_range; > s->vhost_vdpa.shadow_data = svq;