Jason Wang
2022-Dec-16 07:35 UTC
[PATCH v9 12/12] vdpa: always start CVQ in SVQ mode if possible
On Thu, Dec 15, 2022 at 7:32 PM Eugenio P?rez <eperezma at redhat.com> wrote:> > Isolate control virtqueue in its own group, allowing to intercept control > commands but letting dataplane run totally passthrough to the guest. > > Signed-off-by: Eugenio P?rez <eperezma at redhat.com>Acked-by: Jason Wang <jasowang at redhat.com> Thanks> --- > v9: > * Reuse iova_range fetched from the device at initialization, instead of > fetch it again at vhost_vdpa_net_cvq_start. > * Add comment about how migration is blocked in case ASID does not met > our expectations. > * Delete warning about CVQ group not being independent. > > v8: > * Do not allocate iova_tree on net_init_vhost_vdpa if only CVQ is > shadowed. Move the iova_tree handling in this case to > vhost_vdpa_net_cvq_start and vhost_vdpa_net_cvq_stop. > > v7: > * Never ask for number of address spaces, just react if isolation is not > possible. > * Return ASID ioctl errors instead of masking them as if the device has > no asid. > * Simplify net_init_vhost_vdpa logic > * Add "if possible" suffix > > v6: > * Disable control SVQ if the device does not support it because of > features. > > v5: > * Fixing the not adding cvq buffers when x-svq=on is specified. > * Move vring state in vhost_vdpa_get_vring_group instead of using a > parameter. > * Rename VHOST_VDPA_NET_CVQ_PASSTHROUGH to VHOST_VDPA_NET_DATA_ASID > > v4: > * Squash vhost_vdpa_cvq_group_is_independent. > * Rebased on last CVQ start series, that allocated CVQ cmd bufs at load > * Do not check for cvq index on vhost_vdpa_net_prepare, we only have one > that callback registered in that NetClientInfo. > > v3: > * Make asid related queries print a warning instead of returning an > error and stop the start of qemu. > --- > hw/virtio/vhost-vdpa.c | 3 +- > net/vhost-vdpa.c | 110 ++++++++++++++++++++++++++++++++++++++++- > 2 files changed, 111 insertions(+), 2 deletions(-) > > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c > index 48d8c60e76..8cd00f5a96 100644 > --- a/hw/virtio/vhost-vdpa.c > +++ b/hw/virtio/vhost-vdpa.c > @@ -638,7 +638,8 @@ static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev) > { > uint64_t features; > uint64_t f = 0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2 | > - 0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH; > + 0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH | > + 0x1ULL << VHOST_BACKEND_F_IOTLB_ASID; > int r; > > if (vhost_vdpa_call(dev, VHOST_GET_BACKEND_FEATURES, &features)) { > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 710c5efe96..d36664f33a 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -102,6 +102,8 @@ static const uint64_t vdpa_svq_device_features > BIT_ULL(VIRTIO_NET_F_RSC_EXT) | > BIT_ULL(VIRTIO_NET_F_STANDBY); > > +#define VHOST_VDPA_NET_CVQ_ASID 1 > + > VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc) > { > VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); > @@ -243,6 +245,40 @@ static NetClientInfo net_vhost_vdpa_info = { > .check_peer_type = vhost_vdpa_check_peer_type, > }; > > +static int64_t vhost_vdpa_get_vring_group(int device_fd, unsigned vq_index) > +{ > + struct vhost_vring_state state = { > + .index = vq_index, > + }; > + int r = ioctl(device_fd, VHOST_VDPA_GET_VRING_GROUP, &state); > + > + if (unlikely(r < 0)) { > + error_report("Cannot get VQ %u group: %s", vq_index, > + g_strerror(errno)); > + return r; > + } > + > + return state.num; > +} > + > +static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v, > + unsigned vq_group, > + unsigned asid_num) > +{ > + struct vhost_vring_state asid = { > + .index = vq_group, > + .num = asid_num, > + }; > + int r; > + > + r = ioctl(v->device_fd, VHOST_VDPA_SET_GROUP_ASID, &asid); > + if (unlikely(r < 0)) { > + error_report("Can't set vq group %u asid %u, errno=%d (%s)", > + asid.index, asid.num, errno, g_strerror(errno)); > + } > + return r; > +} > + > static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr) > { > VhostIOVATree *tree = v->iova_tree; > @@ -317,11 +353,75 @@ dma_map_err: > static int vhost_vdpa_net_cvq_start(NetClientState *nc) > { > VhostVDPAState *s; > - int r; > + struct vhost_vdpa *v; > + uint64_t backend_features; > + int64_t cvq_group; > + int cvq_index, r; > > assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); > > s = DO_UPCAST(VhostVDPAState, nc, nc); > + v = &s->vhost_vdpa; > + > + v->shadow_data = s->always_svq; > + v->shadow_vqs_enabled = s->always_svq; > + s->vhost_vdpa.address_space_id = VHOST_VDPA_GUEST_PA_ASID; > + > + if (s->always_svq) { > + /* SVQ is already configured for all virtqueues */ > + goto out; > + } > + > + /* > + * If we early return in these cases SVQ will not be enabled. The migration > + * will be blocked as long as vhost-vdpa backends will not offer _F_LOG. > + * > + * Calling VHOST_GET_BACKEND_FEATURES as they are not available in v->dev > + * yet. > + */ > + r = ioctl(v->device_fd, VHOST_GET_BACKEND_FEATURES, &backend_features); > + if (unlikely(r < 0)) { > + error_report("Cannot get vdpa backend_features: %s(%d)", > + g_strerror(errno), errno); > + return -1; > + } > + if (!(backend_features & VHOST_BACKEND_F_IOTLB_ASID) || > + !vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) { > + return 0; > + } > + > + /* > + * Check if all the virtqueues of the virtio device are in a different vq > + * than the last vq. VQ group of last group passed in cvq_group. > + */ > + cvq_index = v->dev->vq_index_end - 1; > + cvq_group = vhost_vdpa_get_vring_group(v->device_fd, cvq_index); > + if (unlikely(cvq_group < 0)) { > + return cvq_group; > + } > + for (int i = 0; i < cvq_index; ++i) { > + int64_t group = vhost_vdpa_get_vring_group(v->device_fd, i); > + > + if (unlikely(group < 0)) { > + return group; > + } > + > + if (group == cvq_group) { > + return 0; > + } > + } > + > + r = vhost_vdpa_set_address_space_id(v, cvq_group, VHOST_VDPA_NET_CVQ_ASID); > + if (unlikely(r < 0)) { > + return r; > + } > + > + v->iova_tree = vhost_iova_tree_new(v->iova_range.first, > + v->iova_range.last); > + v->shadow_vqs_enabled = true; > + s->vhost_vdpa.address_space_id = VHOST_VDPA_NET_CVQ_ASID; > + > +out: > if (!s->vhost_vdpa.shadow_vqs_enabled) { > return 0; > } > @@ -350,6 +450,14 @@ static void vhost_vdpa_net_cvq_stop(NetClientState *nc) > if (s->vhost_vdpa.shadow_vqs_enabled) { > vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer); > vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->status); > + if (!s->always_svq) { > + /* > + * If only the CVQ is shadowed we can delete this safely. > + * If all the VQs are shadows this will be needed by the time the > + * device is started again to register SVQ vrings and similar. > + */ > + g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete); > + } > } > } > > -- > 2.31.1 >