/* * vhost-vdpa.c * * Copyright(c) 2017-2018 Intel Corporation. * Copyright(c) 2020 Red Hat, Inc. * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #include "qemu/osdep.h" #include "clients.h" #include "hw/virtio/virtio-net.h" #include "net/vhost_net.h" #include "net/vhost-vdpa.h" #include "hw/virtio/vhost-vdpa.h" #include "qemu/config-file.h" #include "qemu/error-report.h" #include "qemu/log.h" #include "qemu/memalign.h" #include "qemu/option.h" #include "qapi/error.h" #include #include #include #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 */ void *cvq_cmd_out_buffer; virtio_net_ctrl_ack *status; /* The device always have SVQ enabled */ bool always_svq; /* The device can isolate CVQ in its own ASID */ bool cvq_isolated; bool started; } VhostVDPAState; /* * The array is sorted alphabetically in ascending order, * with the exception of VHOST_INVALID_FEATURE_BIT, * which should always be the last entry. */ const int vdpa_feature_bits[] = { VIRTIO_F_ANY_LAYOUT, VIRTIO_F_IOMMU_PLATFORM, VIRTIO_F_NOTIFY_ON_EMPTY, VIRTIO_F_RING_PACKED, VIRTIO_F_RING_RESET, VIRTIO_F_VERSION_1, VIRTIO_NET_F_CSUM, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, VIRTIO_NET_F_CTRL_MAC_ADDR, VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_RX_EXTRA, VIRTIO_NET_F_CTRL_VLAN, VIRTIO_NET_F_CTRL_VQ, VIRTIO_NET_F_GSO, VIRTIO_NET_F_GUEST_CSUM, VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, VIRTIO_NET_F_GUEST_UFO, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_TSO6, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_MQ, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_MTU, VIRTIO_NET_F_RSS, VIRTIO_NET_F_STATUS, VIRTIO_RING_F_EVENT_IDX, VIRTIO_RING_F_INDIRECT_DESC, /* VHOST_INVALID_FEATURE_BIT should always be the last entry */ VHOST_INVALID_FEATURE_BIT }; /** Supported device specific feature bits with SVQ */ static const uint64_t vdpa_svq_device_features = BIT_ULL(VIRTIO_NET_F_CSUM) | BIT_ULL(VIRTIO_NET_F_GUEST_CSUM) | BIT_ULL(VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) | BIT_ULL(VIRTIO_NET_F_MTU) | BIT_ULL(VIRTIO_NET_F_MAC) | BIT_ULL(VIRTIO_NET_F_GUEST_TSO4) | BIT_ULL(VIRTIO_NET_F_GUEST_TSO6) | BIT_ULL(VIRTIO_NET_F_GUEST_ECN) | BIT_ULL(VIRTIO_NET_F_GUEST_UFO) | BIT_ULL(VIRTIO_NET_F_HOST_TSO4) | BIT_ULL(VIRTIO_NET_F_HOST_TSO6) | BIT_ULL(VIRTIO_NET_F_HOST_ECN) | BIT_ULL(VIRTIO_NET_F_HOST_UFO) | BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) | BIT_ULL(VIRTIO_NET_F_STATUS) | BIT_ULL(VIRTIO_NET_F_CTRL_VQ) | BIT_ULL(VIRTIO_NET_F_CTRL_RX) | BIT_ULL(VIRTIO_NET_F_CTRL_RX_EXTRA) | BIT_ULL(VIRTIO_NET_F_MQ) | BIT_ULL(VIRTIO_F_ANY_LAYOUT) | BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR) | /* VHOST_F_LOG_ALL is exposed by SVQ */ BIT_ULL(VHOST_F_LOG_ALL) | BIT_ULL(VIRTIO_NET_F_RSC_EXT) | BIT_ULL(VIRTIO_NET_F_STANDBY) | BIT_ULL(VIRTIO_NET_F_SPEED_DUPLEX); #define VHOST_VDPA_NET_CVQ_ASID 1 VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); return s->vhost_net; } static size_t vhost_vdpa_net_cvq_cmd_len(void) { /* * MAC_TABLE_SET is the ctrl command that produces the longer out buffer. * In buffer is always 1 byte, so it should fit here */ return sizeof(struct virtio_net_ctrl_hdr) + 2 * sizeof(struct virtio_net_ctrl_mac) + MAC_TABLE_ENTRIES * ETH_ALEN; } static size_t vhost_vdpa_net_cvq_cmd_page_len(void) { return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(), qemu_real_host_page_size()); } static bool vhost_vdpa_net_valid_svq_features(uint64_t features, Error **errp) { uint64_t invalid_dev_features = features & ~vdpa_svq_device_features & /* Transport are all accepted at this point */ ~MAKE_64BIT_MASK(VIRTIO_TRANSPORT_F_START, VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START); if (invalid_dev_features) { error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64, invalid_dev_features); return false; } return vhost_svq_valid_features(features, errp); } static int vhost_vdpa_net_check_device_id(struct vhost_net *net) { uint32_t device_id; int ret; struct vhost_dev *hdev; hdev = (struct vhost_dev *)&net->dev; ret = hdev->vhost_ops->vhost_get_device_id(hdev, &device_id); if (device_id != VIRTIO_ID_NET) { return -ENOTSUP; } return ret; } static int vhost_vdpa_add(NetClientState *ncs, void *be, int queue_pair_index, int nvqs) { VhostNetOptions options; struct vhost_net *net = NULL; VhostVDPAState *s; int ret; options.backend_type = VHOST_BACKEND_TYPE_VDPA; assert(ncs->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); s = DO_UPCAST(VhostVDPAState, nc, ncs); options.net_backend = ncs; options.opaque = be; options.busyloop_timeout = 0; options.nvqs = nvqs; net = vhost_net_init(&options); if (!net) { error_report("failed to init vhost_net for queue"); goto err_init; } s->vhost_net = net; ret = vhost_vdpa_net_check_device_id(net); if (ret) { goto err_check; } return 0; err_check: vhost_net_cleanup(net); g_free(net); err_init: return -1; } static void vhost_vdpa_cleanup(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); /* * If a peer NIC is attached, do not cleanup anything. * Cleanup will happen as a part of qemu_cleanup() -> net_cleanup() * when the guest is shutting down. */ if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) { return; } munmap(s->cvq_cmd_out_buffer, vhost_vdpa_net_cvq_cmd_page_len()); munmap(s->status, vhost_vdpa_net_cvq_cmd_page_len()); if (s->vhost_net) { vhost_net_cleanup(s->vhost_net); g_free(s->vhost_net); s->vhost_net = NULL; } if (s->vhost_vdpa.device_fd >= 0) { qemu_close(s->vhost_vdpa.device_fd); s->vhost_vdpa.device_fd = -1; } } static bool vhost_vdpa_has_vnet_hdr(NetClientState *nc) { assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); return true; } static bool vhost_vdpa_has_ufo(NetClientState *nc) { assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); uint64_t features = 0; features |= (1ULL << VIRTIO_NET_F_HOST_UFO); features = vhost_net_get_features(s->vhost_net, features); return !!(features & (1ULL << VIRTIO_NET_F_HOST_UFO)); } static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc, Error **errp) { const char *driver = object_class_get_name(oc); if (!g_str_has_prefix(driver, "virtio-net-")) { error_setg(errp, "vhost-vdpa requires frontend driver virtio-net-*"); return false; } return true; } /** Dummy receive in case qemu falls back to userland tap networking */ static ssize_t vhost_vdpa_receive(NetClientState *nc, const uint8_t *buf, size_t size) { return size; } /** From any vdpa net client, get the netclient of the first queue pair */ static VhostVDPAState *vhost_vdpa_net_first_nc_vdpa(VhostVDPAState *s) { NICState *nic = qemu_get_nic(s->nc.peer); NetClientState *nc0 = qemu_get_peer(nic->ncs, 0); 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); } } static int vhost_vdpa_net_data_start(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); struct vhost_vdpa *v = &s->vhost_vdpa; 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; } if (v->shadow_vqs_enabled) { VhostVDPAState *s0 = vhost_vdpa_net_first_nc_vdpa(s); v->iova_tree = s0->vhost_vdpa.iova_tree; } return 0; } static void vhost_vdpa_net_client_stop(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); struct vhost_dev *dev; assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); if (s->vhost_vdpa.index == 0) { remove_migration_state_change_notifier(&s->migration_state); } 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); } else { s->vhost_vdpa.iova_tree = NULL; } } static NetClientInfo net_vhost_vdpa_info = { .type = NET_CLIENT_DRIVER_VHOST_VDPA, .size = sizeof(VhostVDPAState), .receive = vhost_vdpa_receive, .start = vhost_vdpa_net_data_start, .stop = vhost_vdpa_net_client_stop, .cleanup = vhost_vdpa_cleanup, .has_vnet_hdr = vhost_vdpa_has_vnet_hdr, .has_ufo = vhost_vdpa_has_ufo, .check_peer_type = vhost_vdpa_check_peer_type, }; static int64_t vhost_vdpa_get_vring_group(int device_fd, unsigned vq_index, Error **errp) { struct vhost_vring_state state = { .index = vq_index, }; int r = ioctl(device_fd, VHOST_VDPA_GET_VRING_GROUP, &state); if (unlikely(r < 0)) { r = -errno; error_setg_errno(errp, errno, "Cannot get VQ %u group", vq_index); 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; DMAMap needle = { /* * No need to specify size or to look for more translations since * this contiguous chunk was allocated by us. */ .translated_addr = (hwaddr)(uintptr_t)addr, }; const DMAMap *map = vhost_iova_tree_find_iova(tree, &needle); int r; if (unlikely(!map)) { error_report("Cannot locate expected map"); return; } r = vhost_vdpa_dma_unmap(v, v->address_space_id, map->iova, map->size + 1); if (unlikely(r != 0)) { error_report("Device cannot unmap: %s(%d)", g_strerror(r), r); } vhost_iova_tree_remove(tree, *map); } /** Map CVQ buffer. */ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, bool write) { DMAMap map = {}; int r; map.translated_addr = (hwaddr)(uintptr_t)buf; map.size = size - 1; map.perm = write ? IOMMU_RW : IOMMU_RO, r = vhost_iova_tree_map_alloc(v->iova_tree, &map); if (unlikely(r != IOVA_OK)) { error_report("Cannot map injected element"); return r; } r = vhost_vdpa_dma_map(v, v->address_space_id, map.iova, vhost_vdpa_net_cvq_cmd_page_len(), buf, !write); if (unlikely(r < 0)) { goto dma_map_err; } return 0; dma_map_err: vhost_iova_tree_remove(v->iova_tree, map); return r; } static int vhost_vdpa_net_cvq_start(NetClientState *nc) { VhostVDPAState *s, *s0; struct vhost_vdpa *v; int64_t cvq_group; int r; Error *err = NULL; assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); s = DO_UPCAST(VhostVDPAState, nc, nc); v = &s->vhost_vdpa; 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->vhost_vdpa.shadow_data) { /* 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. */ if (!vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) { return 0; } if (!s->cvq_isolated) { return 0; } cvq_group = vhost_vdpa_get_vring_group(v->device_fd, v->dev->vq_index_end - 1, &err); if (unlikely(cvq_group < 0)) { error_report_err(err); return cvq_group; } r = vhost_vdpa_set_address_space_id(v, cvq_group, VHOST_VDPA_NET_CVQ_ASID); if (unlikely(r < 0)) { return r; } 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; } if (s0->vhost_vdpa.iova_tree) { /* * SVQ is already configured for all virtqueues. Reuse IOVA tree for * simplicity, whether CVQ shares ASID with guest or not, because: * - Memory listener need access to guest's memory addresses allocated * in the IOVA tree. * - There should be plenty of IOVA address space for both ASID not to * worry about collisions between them. Guest's translations are * still validated with virtio virtqueue_pop so there is no risk for * the guest to access memory that it shouldn't. * * To allocate a iova tree per ASID is doable but it complicates the * code and it is not worth it for the moment. */ v->iova_tree = s0->vhost_vdpa.iova_tree; } else { v->iova_tree = vhost_iova_tree_new(v->iova_range.first, v->iova_range.last); } r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer, vhost_vdpa_net_cvq_cmd_page_len(), false); if (unlikely(r < 0)) { return r; } r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->status, vhost_vdpa_net_cvq_cmd_page_len(), true); if (unlikely(r < 0)) { vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer); } return r; } static void vhost_vdpa_net_cvq_stop(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); 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); } vhost_vdpa_net_client_stop(nc); } static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s, size_t out_len, size_t in_len) { /* Buffers for the device */ const struct iovec out = { .iov_base = s->cvq_cmd_out_buffer, .iov_len = out_len, }; const struct iovec in = { .iov_base = s->status, .iov_len = sizeof(virtio_net_ctrl_ack), }; VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0); int r; r = vhost_svq_add(svq, &out, 1, &in, 1, NULL); if (unlikely(r != 0)) { if (unlikely(r == -ENOSPC)) { qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n", __func__); } return r; } /* * We can poll here since we've had BQL from the time we sent the * descriptor. Also, we need to take the answer before SVQ pulls by itself, * when BQL is released */ return vhost_svq_poll(svq); } static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s, uint8_t class, uint8_t cmd, const struct iovec *data_sg, size_t data_num) { const struct virtio_net_ctrl_hdr ctrl = { .class = class, .cmd = cmd, }; size_t data_size = iov_size(data_sg, data_num); assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl)); /* pack the CVQ command header */ memcpy(s->cvq_cmd_out_buffer, &ctrl, sizeof(ctrl)); /* pack the CVQ command command-specific-data */ iov_to_buf(data_sg, data_num, 0, s->cvq_cmd_out_buffer + sizeof(ctrl), data_size); return vhost_vdpa_net_cvq_add(s, data_size + sizeof(ctrl), sizeof(virtio_net_ctrl_ack)); } static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n) { if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) { const struct iovec data = { .iov_base = (void *)n->mac, .iov_len = sizeof(n->mac), }; ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MAC, VIRTIO_NET_CTRL_MAC_ADDR_SET, &data, 1); if (unlikely(dev_written < 0)) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } /* * According to VirtIO standard, "The device MUST have an * empty MAC filtering table on reset.". * * Therefore, there is no need to send this CVQ command if the * driver also sets an empty MAC filter table, which aligns with * the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX) || n->mac_table.in_use == 0) { return 0; } uint32_t uni_entries = n->mac_table.first_multi, uni_macs_size = uni_entries * ETH_ALEN, mul_entries = n->mac_table.in_use - uni_entries, mul_macs_size = mul_entries * ETH_ALEN; struct virtio_net_ctrl_mac uni = { .entries = cpu_to_le32(uni_entries), }; struct virtio_net_ctrl_mac mul = { .entries = cpu_to_le32(mul_entries), }; const struct iovec data[] = { { .iov_base = &uni, .iov_len = sizeof(uni), }, { .iov_base = n->mac_table.macs, .iov_len = uni_macs_size, }, { .iov_base = &mul, .iov_len = sizeof(mul), }, { .iov_base = &n->mac_table.macs[uni_macs_size], .iov_len = mul_macs_size, }, }; ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MAC, VIRTIO_NET_CTRL_MAC_TABLE_SET, data, ARRAY_SIZE(data)); if (unlikely(dev_written < 0)) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } return 0; } static int vhost_vdpa_net_load_mq(VhostVDPAState *s, const VirtIONet *n) { struct virtio_net_ctrl_mq mq; ssize_t dev_written; if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_MQ)) { return 0; } mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs); const struct iovec data = { .iov_base = &mq, .iov_len = sizeof(mq), }; dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MQ, VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &data, 1); if (unlikely(dev_written < 0)) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } return 0; } static int vhost_vdpa_net_load_offloads(VhostVDPAState *s, const VirtIONet *n) { uint64_t offloads; ssize_t dev_written; if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { return 0; } if (n->curr_guest_offloads == virtio_net_supported_guest_offloads(n)) { /* * According to VirtIO standard, "Upon feature negotiation * corresponding offload gets enabled to preserve * backward compatibility.". * * Therefore, there is no need to send this CVQ command if the * driver also enables all supported offloads, which aligns with * the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ return 0; } offloads = cpu_to_le64(n->curr_guest_offloads); const struct iovec data = { .iov_base = &offloads, .iov_len = sizeof(offloads), }; dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_GUEST_OFFLOADS, VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, &data, 1); if (unlikely(dev_written < 0)) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } return 0; } static int vhost_vdpa_net_load_rx_mode(VhostVDPAState *s, uint8_t cmd, uint8_t on) { const struct iovec data = { .iov_base = &on, .iov_len = sizeof(on), }; return vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_RX, cmd, &data, 1); } static int vhost_vdpa_net_load_rx(VhostVDPAState *s, const VirtIONet *n) { ssize_t dev_written; if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX)) { return 0; } /* * According to virtio_net_reset(), device turns promiscuous mode * on by default. * * Addtionally, according to VirtIO standard, "Since there are * no guarantees, it can use a hash filter or silently switch to * allmulti or promiscuous mode if it is given too many addresses.". * QEMU marks `n->mac_table.uni_overflow` if guest sets too many * non-multicast MAC addresses, indicating that promiscuous mode * should be enabled. * * Therefore, QEMU should only send this CVQ command if the * `n->mac_table.uni_overflow` is not marked and `n->promisc` is off, * which sets promiscuous mode on, different from the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (!n->mac_table.uni_overflow && !n->promisc) { dev_written = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_PROMISC, 0); if (unlikely(dev_written < 0)) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } /* * According to virtio_net_reset(), device turns all-multicast mode * off by default. * * According to VirtIO standard, "Since there are no guarantees, * it can use a hash filter or silently switch to allmulti or * promiscuous mode if it is given too many addresses.". QEMU marks * `n->mac_table.multi_overflow` if guest sets too many * non-multicast MAC addresses. * * Therefore, QEMU should only send this CVQ command if the * `n->mac_table.multi_overflow` is marked or `n->allmulti` is on, * which sets all-multicast mode on, different from the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (n->mac_table.multi_overflow || n->allmulti) { dev_written = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_ALLMULTI, 1); if (unlikely(dev_written < 0)) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX_EXTRA)) { return 0; } /* * According to virtio_net_reset(), device turns all-unicast mode * off by default. * * Therefore, QEMU should only send this CVQ command if the driver * sets all-unicast mode on, different from the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (n->alluni) { dev_written = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_ALLUNI, 1); if (dev_written < 0) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } /* * According to virtio_net_reset(), device turns non-multicast mode * off by default. * * Therefore, QEMU should only send this CVQ command if the driver * sets non-multicast mode on, different from the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (n->nomulti) { dev_written = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_NOMULTI, 1); if (dev_written < 0) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } /* * According to virtio_net_reset(), device turns non-unicast mode * off by default. * * Therefore, QEMU should only send this CVQ command if the driver * sets non-unicast mode on, different from the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (n->nouni) { dev_written = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_NOUNI, 1); if (dev_written < 0) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } /* * According to virtio_net_reset(), device turns non-broadcast mode * off by default. * * Therefore, QEMU should only send this CVQ command if the driver * sets non-broadcast mode on, different from the device's defaults. * * Note that the device's defaults can mismatch the driver's * configuration only at live migration. */ if (n->nobcast) { dev_written = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_NOBCAST, 1); if (dev_written < 0) { return dev_written; } if (*s->status != VIRTIO_NET_OK) { return -EIO; } } return 0; } static int vhost_vdpa_net_load(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); struct vhost_vdpa *v = &s->vhost_vdpa; const VirtIONet *n; int r; assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA); if (!v->shadow_vqs_enabled) { return 0; } n = VIRTIO_NET(v->dev->vdev); r = vhost_vdpa_net_load_mac(s, n); if (unlikely(r < 0)) { return r; } r = vhost_vdpa_net_load_mq(s, n); if (unlikely(r)) { return r; } r = vhost_vdpa_net_load_offloads(s, n); if (unlikely(r)) { return r; } r = vhost_vdpa_net_load_rx(s, n); if (unlikely(r)) { return r; } return 0; } static NetClientInfo net_vhost_vdpa_cvq_info = { .type = NET_CLIENT_DRIVER_VHOST_VDPA, .size = sizeof(VhostVDPAState), .receive = vhost_vdpa_receive, .start = vhost_vdpa_net_cvq_start, .load = vhost_vdpa_net_load, .stop = vhost_vdpa_net_cvq_stop, .cleanup = vhost_vdpa_cleanup, .has_vnet_hdr = vhost_vdpa_has_vnet_hdr, .has_ufo = vhost_vdpa_has_ufo, .check_peer_type = vhost_vdpa_check_peer_type, }; /* * Forward the excessive VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command to * vdpa device. * * Considering that QEMU cannot send the entire filter table to the * vdpa device, it should send the VIRTIO_NET_CTRL_RX_PROMISC CVQ * command to enable promiscuous mode to receive all packets, * according to VirtIO standard, "Since there are no guarantees, * it can use a hash filter or silently switch to allmulti or * promiscuous mode if it is given too many addresses.". * * Since QEMU ignores MAC addresses beyond `MAC_TABLE_ENTRIES` and * marks `n->mac_table.x_overflow` accordingly, it should have * the same effect on the device model to receive * (`MAC_TABLE_ENTRIES` + 1) or more non-multicast MAC addresses. * The same applies to multicast MAC addresses. * * Therefore, QEMU can provide the device model with a fake * VIRTIO_NET_CTRL_MAC_TABLE_SET command with (`MAC_TABLE_ENTRIES` + 1) * non-multicast MAC addresses and (`MAC_TABLE_ENTRIES` + 1) multicast * MAC addresses. This ensures that the device model marks * `n->mac_table.uni_overflow` and `n->mac_table.multi_overflow`, * allowing all packets to be received, which aligns with the * state of the vdpa device. */ static int vhost_vdpa_net_excessive_mac_filter_cvq_add(VhostVDPAState *s, VirtQueueElement *elem, struct iovec *out) { struct virtio_net_ctrl_mac mac_data, *mac_ptr; struct virtio_net_ctrl_hdr *hdr_ptr; uint32_t cursor; ssize_t r; /* parse the non-multicast MAC address entries from CVQ command */ cursor = sizeof(*hdr_ptr); r = iov_to_buf(elem->out_sg, elem->out_num, cursor, &mac_data, sizeof(mac_data)); if (unlikely(r != sizeof(mac_data))) { /* * If the CVQ command is invalid, we should simulate the vdpa device * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command */ *s->status = VIRTIO_NET_ERR; return sizeof(*s->status); } cursor += sizeof(mac_data) + le32_to_cpu(mac_data.entries) * ETH_ALEN; /* parse the multicast MAC address entries from CVQ command */ r = iov_to_buf(elem->out_sg, elem->out_num, cursor, &mac_data, sizeof(mac_data)); if (r != sizeof(mac_data)) { /* * If the CVQ command is invalid, we should simulate the vdpa device * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command */ *s->status = VIRTIO_NET_ERR; return sizeof(*s->status); } cursor += sizeof(mac_data) + le32_to_cpu(mac_data.entries) * ETH_ALEN; /* validate the CVQ command */ if (iov_size(elem->out_sg, elem->out_num) != cursor) { /* * If the CVQ command is invalid, we should simulate the vdpa device * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command */ *s->status = VIRTIO_NET_ERR; return sizeof(*s->status); } /* * According to VirtIO standard, "Since there are no guarantees, * it can use a hash filter or silently switch to allmulti or * promiscuous mode if it is given too many addresses.". * * Therefore, considering that QEMU is unable to send the entire * filter table to the vdpa device, it should send the * VIRTIO_NET_CTRL_RX_PROMISC CVQ command to enable promiscuous mode */ r = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_PROMISC, 1); if (unlikely(r < 0)) { return r; } if (*s->status != VIRTIO_NET_OK) { return sizeof(*s->status); } /* * QEMU should also send a fake VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ * command to the device model, including (`MAC_TABLE_ENTRIES` + 1) * non-multicast MAC addresses and (`MAC_TABLE_ENTRIES` + 1) * multicast MAC addresses. * * By doing so, the device model can mark `n->mac_table.uni_overflow` * and `n->mac_table.multi_overflow`, enabling all packets to be * received, which aligns with the state of the vdpa device. */ cursor = 0; uint32_t fake_uni_entries = MAC_TABLE_ENTRIES + 1, fake_mul_entries = MAC_TABLE_ENTRIES + 1, fake_cvq_size = sizeof(struct virtio_net_ctrl_hdr) + sizeof(mac_data) + fake_uni_entries * ETH_ALEN + sizeof(mac_data) + fake_mul_entries * ETH_ALEN; assert(fake_cvq_size < vhost_vdpa_net_cvq_cmd_page_len()); out->iov_len = fake_cvq_size; /* pack the header for fake CVQ command */ hdr_ptr = out->iov_base + cursor; hdr_ptr->class = VIRTIO_NET_CTRL_MAC; hdr_ptr->cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET; cursor += sizeof(*hdr_ptr); /* * Pack the non-multicast MAC addresses part for fake CVQ command. * * According to virtio_net_handle_mac(), QEMU doesn't verify the MAC * addresses provieded in CVQ command. Therefore, only the entries * field need to be prepared in the CVQ command. */ mac_ptr = out->iov_base + cursor; mac_ptr->entries = cpu_to_le32(fake_uni_entries); cursor += sizeof(*mac_ptr) + fake_uni_entries * ETH_ALEN; /* * Pack the multicast MAC addresses part for fake CVQ command. * * According to virtio_net_handle_mac(), QEMU doesn't verify the MAC * addresses provieded in CVQ command. Therefore, only the entries * field need to be prepared in the CVQ command. */ mac_ptr = out->iov_base + cursor; mac_ptr->entries = cpu_to_le32(fake_mul_entries); /* * Simulating QEMU poll a vdpa device used buffer * for VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command */ return sizeof(*s->status); } /** * Validate and copy control virtqueue commands. * * Following QEMU guidelines, we offer a copy of the buffers to the device to * prevent TOCTOU bugs. */ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq, VirtQueueElement *elem, void *opaque) { VhostVDPAState *s = opaque; size_t in_len; const struct virtio_net_ctrl_hdr *ctrl; virtio_net_ctrl_ack status = VIRTIO_NET_ERR; /* Out buffer sent to both the vdpa device and the device model */ struct iovec out = { .iov_base = s->cvq_cmd_out_buffer, }; /* in buffer used for device model */ const struct iovec in = { .iov_base = &status, .iov_len = sizeof(status), }; ssize_t dev_written = -EINVAL; out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0, s->cvq_cmd_out_buffer, vhost_vdpa_net_cvq_cmd_page_len()); ctrl = s->cvq_cmd_out_buffer; if (ctrl->class == VIRTIO_NET_CTRL_ANNOUNCE) { /* * Guest announce capability is emulated by qemu, so don't forward to * the device. */ dev_written = sizeof(status); *s->status = VIRTIO_NET_OK; } else if (unlikely(ctrl->class == VIRTIO_NET_CTRL_MAC && ctrl->cmd == VIRTIO_NET_CTRL_MAC_TABLE_SET && iov_size(elem->out_sg, elem->out_num) > out.iov_len)) { /* * Due to the size limitation of the out buffer sent to the vdpa device, * which is determined by vhost_vdpa_net_cvq_cmd_page_len(), excessive * MAC addresses set by the driver for the filter table can cause * truncation of the CVQ command in QEMU. As a result, the vdpa device * rejects the flawed CVQ command. * * Therefore, QEMU must handle this situation instead of sending * the CVQ command direclty. */ dev_written = vhost_vdpa_net_excessive_mac_filter_cvq_add(s, elem, &out); if (unlikely(dev_written < 0)) { goto out; } } else { dev_written = vhost_vdpa_net_cvq_add(s, out.iov_len, sizeof(status)); if (unlikely(dev_written < 0)) { goto out; } } if (unlikely(dev_written < sizeof(status))) { error_report("Insufficient written data (%zu)", dev_written); goto out; } if (*s->status != VIRTIO_NET_OK) { goto out; } status = VIRTIO_NET_ERR; virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, &out, 1); if (status != VIRTIO_NET_OK) { error_report("Bad CVQ processing in model"); } out: in_len = iov_from_buf(elem->in_sg, elem->in_num, 0, &status, sizeof(status)); if (unlikely(in_len < sizeof(status))) { error_report("Bad device CVQ written length"); } vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status))); /* * `elem` belongs to vhost_vdpa_net_handle_ctrl_avail() only when * the function successfully forwards the CVQ command, indicated * by a non-negative value of `dev_written`. Otherwise, it still * belongs to SVQ. * This function should only free the `elem` when it owns. */ if (dev_written >= 0) { g_free(elem); } return dev_written < 0 ? dev_written : 0; } static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = { .avail_handler = vhost_vdpa_net_handle_ctrl_avail, }; /** * Probe if CVQ is isolated * * @device_fd The vdpa device fd * @features Features offered by the device. * @cvq_index The control vq pair index * * Returns <0 in case of failure, 0 if false and 1 if true. */ static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features, int cvq_index, Error **errp) { uint64_t backend_features; int64_t cvq_group; uint8_t status = VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER; int r; ERRP_GUARD(); r = ioctl(device_fd, VHOST_GET_BACKEND_FEATURES, &backend_features); if (unlikely(r < 0)) { error_setg_errno(errp, errno, "Cannot get vdpa backend_features"); return r; } if (!(backend_features & BIT_ULL(VHOST_BACKEND_F_IOTLB_ASID))) { return 0; } r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status); if (unlikely(r)) { error_setg_errno(errp, -r, "Cannot set device status"); goto out; } r = ioctl(device_fd, VHOST_SET_FEATURES, &features); if (unlikely(r)) { error_setg_errno(errp, -r, "Cannot set features"); goto out; } status |= VIRTIO_CONFIG_S_FEATURES_OK; r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status); if (unlikely(r)) { error_setg_errno(errp, -r, "Cannot set device status"); goto out; } cvq_group = vhost_vdpa_get_vring_group(device_fd, cvq_index, errp); if (unlikely(cvq_group < 0)) { if (cvq_group != -ENOTSUP) { r = cvq_group; goto out; } /* * The kernel report VHOST_BACKEND_F_IOTLB_ASID if the vdpa frontend * support ASID even if the parent driver does not. The CVQ cannot be * isolated in this case. */ error_free(*errp); *errp = NULL; r = 0; goto out; } for (int i = 0; i < cvq_index; ++i) { int64_t group = vhost_vdpa_get_vring_group(device_fd, i, errp); if (unlikely(group < 0)) { r = group; goto out; } if (group == (int64_t)cvq_group) { r = 0; goto out; } } r = 1; out: status = 0; ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status); return r; } static NetClientState *net_vhost_vdpa_init(NetClientState *peer, const char *device, const char *name, int vdpa_device_fd, int queue_pair_index, int nvqs, bool is_datapath, bool svq, struct vhost_vdpa_iova_range iova_range, uint64_t features, Error **errp) { NetClientState *nc = NULL; VhostVDPAState *s; int ret = 0; assert(name); int cvq_isolated; if (is_datapath) { nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, name); } else { cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features, queue_pair_index * 2, errp); if (unlikely(cvq_isolated < 0)) { return NULL; } nc = qemu_new_net_control_client(&net_vhost_vdpa_cvq_info, peer, device, name); } qemu_set_info_str(nc, TYPE_VHOST_VDPA); s = DO_UPCAST(VhostVDPAState, nc, nc); 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; if (queue_pair_index == 0) { vhost_vdpa_net_valid_svq_features(features, &s->vhost_vdpa.migration_blocker); } else if (!is_datapath) { s->cvq_cmd_out_buffer = mmap(NULL, vhost_vdpa_net_cvq_cmd_page_len(), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); s->status = mmap(NULL, vhost_vdpa_net_cvq_cmd_page_len(), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops; s->vhost_vdpa.shadow_vq_ops_opaque = s; s->cvq_isolated = cvq_isolated; /* * TODO: We cannot migrate devices with CVQ and no x-svq enabled as * there is no way to set the device state (MAC, MQ, etc) before * starting the datapath. * * Migration blocker ownership now belongs to s->vhost_vdpa. */ if (!svq) { error_setg(&s->vhost_vdpa.migration_blocker, "net vdpa cannot migrate with CVQ feature"); } } ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs); if (ret) { qemu_del_net_client(nc); return NULL; } return nc; } static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp) { int ret = ioctl(fd, VHOST_GET_FEATURES, features); if (unlikely(ret < 0)) { error_setg_errno(errp, errno, "Fail to query features from vhost-vDPA device"); } return ret; } static int vhost_vdpa_get_max_queue_pairs(int fd, uint64_t features, int *has_cvq, Error **errp) { unsigned long config_size = offsetof(struct vhost_vdpa_config, buf); g_autofree struct vhost_vdpa_config *config = NULL; __virtio16 *max_queue_pairs; int ret; if (features & (1 << VIRTIO_NET_F_CTRL_VQ)) { *has_cvq = 1; } else { *has_cvq = 0; } if (features & (1 << VIRTIO_NET_F_MQ)) { config = g_malloc0(config_size + sizeof(*max_queue_pairs)); config->off = offsetof(struct virtio_net_config, max_virtqueue_pairs); config->len = sizeof(*max_queue_pairs); ret = ioctl(fd, VHOST_VDPA_GET_CONFIG, config); if (ret) { error_setg(errp, "Fail to get config from vhost-vDPA device"); return -ret; } max_queue_pairs = (__virtio16 *)&config->buf; return lduw_le_p(max_queue_pairs); } return 1; } int net_init_vhost_vdpa(const Netdev *netdev, const char *name, NetClientState *peer, Error **errp) { const NetdevVhostVDPAOptions *opts; uint64_t features; int vdpa_device_fd; g_autofree NetClientState **ncs = NULL; struct vhost_vdpa_iova_range iova_range; NetClientState *nc; int queue_pairs, r, i = 0, has_cvq = 0; assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA); opts = &netdev->u.vhost_vdpa; if (!opts->vhostdev && !opts->vhostfd) { error_setg(errp, "vhost-vdpa: neither vhostdev= nor vhostfd= was specified"); return -1; } if (opts->vhostdev && opts->vhostfd) { error_setg(errp, "vhost-vdpa: vhostdev= and vhostfd= are mutually exclusive"); return -1; } if (opts->vhostdev) { vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR, errp); if (vdpa_device_fd == -1) { return -errno; } } else { /* has_vhostfd */ vdpa_device_fd = monitor_fd_param(monitor_cur(), opts->vhostfd, errp); if (vdpa_device_fd == -1) { error_prepend(errp, "vhost-vdpa: unable to parse vhostfd: "); return -1; } } r = vhost_vdpa_get_features(vdpa_device_fd, &features, errp); if (unlikely(r < 0)) { goto err; } queue_pairs = vhost_vdpa_get_max_queue_pairs(vdpa_device_fd, features, &has_cvq, errp); if (queue_pairs < 0) { qemu_close(vdpa_device_fd); return queue_pairs; } r = vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range); if (unlikely(r < 0)) { error_setg(errp, "vhost-vdpa: get iova range failed: %s", strerror(-r)); goto err; } if (opts->x_svq && !vhost_vdpa_net_valid_svq_features(features, errp)) { goto err; } ncs = g_malloc0(sizeof(*ncs) * queue_pairs); for (i = 0; i < queue_pairs; i++) { ncs[i] = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd, i, 2, true, opts->x_svq, iova_range, features, errp); if (!ncs[i]) goto err; } if (has_cvq) { nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd, i, 1, false, opts->x_svq, iova_range, features, errp); if (!nc) goto err; } return 0; err: if (i) { for (i--; i >= 0; i--) { qemu_del_net_client(ncs[i]); } } qemu_close(vdpa_device_fd); return -1; }