// SPDX-License-Identifier: GPL-2.0-only /* * Hyper-V transport for vsock * * Hyper-V Sockets supplies a byte-stream based communication mechanism * between the host and the VM. This driver implements the necessary * support in the VM by introducing the new vsock transport. * * Copyright (c) 2017, Microsoft Corporation. */ #include #include #include #include #include #include /* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some * stricter requirements on the hv_sock ring buffer size of six 4K pages. * hyperv-tlfs defines HV_HYP_PAGE_SIZE as 4K. Newer hosts don't have this * limitation; but, keep the defaults the same for compat. */ #define RINGBUFFER_HVS_RCV_SIZE (HV_HYP_PAGE_SIZE * 6) #define RINGBUFFER_HVS_SND_SIZE (HV_HYP_PAGE_SIZE * 6) #define RINGBUFFER_HVS_MAX_SIZE (HV_HYP_PAGE_SIZE * 64) /* The MTU is 16KB per the host side's design */ #define HVS_MTU_SIZE (1024 * 16) /* How long to wait for graceful shutdown of a connection */ #define HVS_CLOSE_TIMEOUT (8 * HZ) struct vmpipe_proto_header { u32 pkt_type; u32 data_size; }; /* For recv, we use the VMBus in-place packet iterator APIs to directly copy * data from the ringbuffer into the userspace buffer. */ struct hvs_recv_buf { /* The header before the payload data */ struct vmpipe_proto_header hdr; /* The payload */ u8 data[HVS_MTU_SIZE]; }; /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use * a smaller size, i.e. HVS_SEND_BUF_SIZE, to maximize concurrency between the * guest and the host processing as one VMBUS packet is the smallest processing * unit. * * Note: the buffer can be eliminated in the future when we add new VMBus * ringbuffer APIs that allow us to directly copy data from userspace buffer * to VMBus ringbuffer. */ #define HVS_SEND_BUF_SIZE \ (HV_HYP_PAGE_SIZE - sizeof(struct vmpipe_proto_header)) struct hvs_send_buf { /* The header before the payload data */ struct vmpipe_proto_header hdr; /* The payload */ u8 data[HVS_SEND_BUF_SIZE]; }; #define HVS_HEADER_LEN (sizeof(struct vmpacket_descriptor) + \ sizeof(struct vmpipe_proto_header)) /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and * __hv_pkt_iter_next(). */ #define VMBUS_PKT_TRAILER_SIZE (sizeof(u64)) #define HVS_PKT_LEN(payload_len) (HVS_HEADER_LEN + \ ALIGN((payload_len), 8) + \ VMBUS_PKT_TRAILER_SIZE) /* Upper bound on the size of a VMbus packet for hv_sock */ #define HVS_MAX_PKT_SIZE HVS_PKT_LEN(HVS_MTU_SIZE) union hvs_service_id { guid_t srv_id; struct { unsigned int svm_port; unsigned char b[sizeof(guid_t) - sizeof(unsigned int)]; }; }; /* Per-socket state (accessed via vsk->trans) */ struct hvsock { struct vsock_sock *vsk; guid_t vm_srv_id; guid_t host_srv_id; struct vmbus_channel *chan; struct vmpacket_descriptor *recv_desc; /* The length of the payload not delivered to userland yet */ u32 recv_data_len; /* The offset of the payload */ u32 recv_data_off; /* Have we sent the zero-length packet (FIN)? */ bool fin_sent; }; /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is * (see struct sockaddr_vm). Note: cid is not really used here: * when we write apps to connect to the host, we can only use VMADDR_CID_ANY * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY * as the local cid. * * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV: * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user- * guide/make-integration-service, and the endpoint is with * the below sockaddr: * * struct SOCKADDR_HV * { * ADDRESS_FAMILY Family; * USHORT Reserved; * GUID VmId; * GUID ServiceId; * }; * Note: VmID is not used by Linux VM and actually it isn't transmitted via * VMBus, because here it's obvious the host and the VM can easily identify * each other. Though the VmID is useful on the host, especially in the case * of Windows container, Linux VM doesn't need it at all. * * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit * the available GUID space of SOCKADDR_HV so that we can create a mapping * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing * Hyper-V Sockets apps on the host and in Linux VM is: * **************************************************************************** * The only valid Service GUIDs, from the perspectives of both the host and * * Linux VM, that can be connected by the other end, must conform to this * * format: -facb-11e6-bd58-64006a7986d3. * **************************************************************************** * * When we write apps on the host to connect(), the GUID ServiceID is used. * When we write apps in Linux VM to connect(), we only need to specify the * port and the driver will form the GUID and use that to request the host. * */ /* 00000000-facb-11e6-bd58-64006a7986d3 */ static const guid_t srv_id_template = GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58, 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3); static bool hvs_check_transport(struct vsock_sock *vsk); static bool is_valid_srv_id(const guid_t *id) { return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4); } static unsigned int get_port_by_srv_id(const guid_t *svr_id) { return *((unsigned int *)svr_id); } static void hvs_addr_init(struct sockaddr_vm *addr, const guid_t *svr_id) { unsigned int port = get_port_by_srv_id(svr_id); vsock_addr_init(addr, VMADDR_CID_ANY, port); } static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan) { set_channel_pending_send_size(chan, HVS_PKT_LEN(HVS_SEND_BUF_SIZE)); virt_mb(); } static bool hvs_channel_readable(struct vmbus_channel *chan) { u32 readable = hv_get_bytes_to_read(&chan->inbound); /* 0-size payload means FIN */ return readable >= HVS_PKT_LEN(0); } static int hvs_channel_readable_payload(struct vmbus_channel *chan) { u32 readable = hv_get_bytes_to_read(&chan->inbound); if (readable > HVS_PKT_LEN(0)) { /* At least we have 1 byte to read. We don't need to return * the exact readable bytes: see vsock_stream_recvmsg() -> * vsock_stream_has_data(). */ return 1; } if (readable == HVS_PKT_LEN(0)) { /* 0-size payload means FIN */ return 0; } /* No payload or FIN */ return -1; } static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan) { u32 writeable = hv_get_bytes_to_write(&chan->outbound); size_t ret; /* The ringbuffer mustn't be 100% full, and we should reserve a * zero-length-payload packet for the FIN: see hv_ringbuffer_write() * and hvs_shutdown(). */ if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0)) return 0; ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0); return round_down(ret, 8); } static int __hvs_send_data(struct vmbus_channel *chan, struct vmpipe_proto_header *hdr, size_t to_write) { hdr->pkt_type = 1; hdr->data_size = to_write; return vmbus_sendpacket(chan, hdr, sizeof(*hdr) + to_write, 0, VM_PKT_DATA_INBAND, 0); } static int hvs_send_data(struct vmbus_channel *chan, struct hvs_send_buf *send_buf, size_t to_write) { return __hvs_send_data(chan, &send_buf->hdr, to_write); } static void hvs_channel_cb(void *ctx) { struct sock *sk = (struct sock *)ctx; struct vsock_sock *vsk = vsock_sk(sk); struct hvsock *hvs = vsk->trans; struct vmbus_channel *chan = hvs->chan; if (hvs_channel_readable(chan)) sk->sk_data_ready(sk); if (hv_get_bytes_to_write(&chan->outbound) > 0) sk->sk_write_space(sk); } static void hvs_do_close_lock_held(struct vsock_sock *vsk, bool cancel_timeout) { struct sock *sk = sk_vsock(vsk); sock_set_flag(sk, SOCK_DONE); vsk->peer_shutdown = SHUTDOWN_MASK; if (vsock_stream_has_data(vsk) <= 0) sk->sk_state = TCP_CLOSING; sk->sk_state_change(sk); if (vsk->close_work_scheduled && (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { vsk->close_work_scheduled = false; vsock_remove_sock(vsk); /* Release the reference taken while scheduling the timeout */ sock_put(sk); } } static void hvs_close_connection(struct vmbus_channel *chan) { struct sock *sk = get_per_channel_state(chan); lock_sock(sk); hvs_do_close_lock_held(vsock_sk(sk), true); release_sock(sk); /* Release the refcnt for the channel that's opened in * hvs_open_connection(). */ sock_put(sk); } static void hvs_open_connection(struct vmbus_channel *chan) { guid_t *if_instance, *if_type; unsigned char conn_from_host; struct sockaddr_vm addr; struct sock *sk, *new = NULL; struct vsock_sock *vnew = NULL; struct hvsock *hvs = NULL; struct hvsock *hvs_new = NULL; int rcvbuf; int ret; int sndbuf; if_type = &chan->offermsg.offer.if_type; if_instance = &chan->offermsg.offer.if_instance; conn_from_host = chan->offermsg.offer.u.pipe.user_def[0]; if (!is_valid_srv_id(if_type)) return; hvs_addr_init(&addr, conn_from_host ? if_type : if_instance); sk = vsock_find_bound_socket(&addr); if (!sk) return; lock_sock(sk); if ((conn_from_host && sk->sk_state != TCP_LISTEN) || (!conn_from_host && sk->sk_state != TCP_SYN_SENT)) goto out; if (conn_from_host) { if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) goto out; new = vsock_create_connected(sk); if (!new) goto out; new->sk_state = TCP_SYN_SENT; vnew = vsock_sk(new); hvs_addr_init(&vnew->local_addr, if_type); /* Remote peer is always the host */ vsock_addr_init(&vnew->remote_addr, VMADDR_CID_HOST, VMADDR_PORT_ANY); vnew->remote_addr.svm_port = get_port_by_srv_id(if_instance); ret = vsock_assign_transport(vnew, vsock_sk(sk)); /* Transport assigned (looking at remote_addr) must be the * same where we received the request. */ if (ret || !hvs_check_transport(vnew)) { sock_put(new); goto out; } hvs_new = vnew->trans; hvs_new->chan = chan; } else { hvs = vsock_sk(sk)->trans; hvs->chan = chan; } set_channel_read_mode(chan, HV_CALL_DIRECT); /* Use the socket buffer sizes as hints for the VMBUS ring size. For * server side sockets, 'sk' is the parent socket and thus, this will * allow the child sockets to inherit the size from the parent. Keep * the mins to the default value and align to page size as per VMBUS * requirements. * For the max, the socket core library will limit the socket buffer * size that can be set by the user, but, since currently, the hv_sock * VMBUS ring buffer is physically contiguous allocation, restrict it * further. * Older versions of hv_sock host side code cannot handle bigger VMBUS * ring buffer size. Use the version number to limit the change to newer * versions. */ if (vmbus_proto_version < VERSION_WIN10_V5) { sndbuf = RINGBUFFER_HVS_SND_SIZE; rcvbuf = RINGBUFFER_HVS_RCV_SIZE; } else { sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE); sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE); sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE); rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE); rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE); rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE); } chan->max_pkt_size = HVS_MAX_PKT_SIZE; ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb, conn_from_host ? new : sk); if (ret != 0) { if (conn_from_host) { hvs_new->chan = NULL; sock_put(new); } else { hvs->chan = NULL; } goto out; } set_per_channel_state(chan, conn_from_host ? new : sk); /* This reference will be dropped by hvs_close_connection(). */ sock_hold(conn_from_host ? new : sk); vmbus_set_chn_rescind_callback(chan, hvs_close_connection); /* Set the pending send size to max packet size to always get * notifications from the host when there is enough writable space. * The host is optimized to send notifications only when the pending * size boundary is crossed, and not always. */ hvs_set_channel_pending_send_size(chan); if (conn_from_host) { new->sk_state = TCP_ESTABLISHED; sk_acceptq_added(sk); hvs_new->vm_srv_id = *if_type; hvs_new->host_srv_id = *if_instance; vsock_insert_connected(vnew); vsock_enqueue_accept(sk, new); } else { sk->sk_state = TCP_ESTABLISHED; sk->sk_socket->state = SS_CONNECTED; vsock_insert_connected(vsock_sk(sk)); } sk->sk_state_change(sk); out: /* Release refcnt obtained when we called vsock_find_bound_socket() */ sock_put(sk); release_sock(sk); } static u32 hvs_get_local_cid(void) { return VMADDR_CID_ANY; } static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk) { struct hvsock *hvs; struct sock *sk = sk_vsock(vsk); hvs = kzalloc(sizeof(*hvs), GFP_KERNEL); if (!hvs) return -ENOMEM; vsk->trans = hvs; hvs->vsk = vsk; sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE; sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE; return 0; } static int hvs_connect(struct vsock_sock *vsk) { union hvs_service_id vm, host; struct hvsock *h = vsk->trans; vm.srv_id = srv_id_template; vm.svm_port = vsk->local_addr.svm_port; h->vm_srv_id = vm.srv_id; host.srv_id = srv_id_template; host.svm_port = vsk->remote_addr.svm_port; h->host_srv_id = host.srv_id; return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id); } static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode) { struct vmpipe_proto_header hdr; if (hvs->fin_sent || !hvs->chan) return; /* It can't fail: see hvs_channel_writable_bytes(). */ (void)__hvs_send_data(hvs->chan, &hdr, 0); hvs->fin_sent = true; } static int hvs_shutdown(struct vsock_sock *vsk, int mode) { if (!(mode & SEND_SHUTDOWN)) return 0; hvs_shutdown_lock_held(vsk->trans, mode); return 0; } static void hvs_close_timeout(struct work_struct *work) { struct vsock_sock *vsk = container_of(work, struct vsock_sock, close_work.work); struct sock *sk = sk_vsock(vsk); sock_hold(sk); lock_sock(sk); if (!sock_flag(sk, SOCK_DONE)) hvs_do_close_lock_held(vsk, false); vsk->close_work_scheduled = false; release_sock(sk); sock_put(sk); } /* Returns true, if it is safe to remove socket; false otherwise */ static bool hvs_close_lock_held(struct vsock_sock *vsk) { struct sock *sk = sk_vsock(vsk); if (!(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_CLOSING)) return true; if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK); if (sock_flag(sk, SOCK_DONE)) return true; /* This reference will be dropped by the delayed close routine */ sock_hold(sk); INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout); vsk->close_work_scheduled = true; schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT); return false; } static void hvs_release(struct vsock_sock *vsk) { bool remove_sock; remove_sock = hvs_close_lock_held(vsk); if (remove_sock) vsock_remove_sock(vsk); } static void hvs_destruct(struct vsock_sock *vsk) { struct hvsock *hvs = vsk->trans; struct vmbus_channel *chan = hvs->chan; if (chan) vmbus_hvsock_device_unregister(chan); kfree(hvs); vsk->trans = NULL; } static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) { return -EOPNOTSUPP; } static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, size_t len, int flags) { return -EOPNOTSUPP; } static int hvs_dgram_enqueue(struct vsock_sock *vsk, struct sockaddr_vm *remote, struct msghdr *msg, size_t dgram_len) { return -EOPNOTSUPP; } static bool hvs_dgram_allow(u32 cid, u32 port) { return false; } static int hvs_update_recv_data(struct hvsock *hvs) { struct hvs_recv_buf *recv_buf; u32 pkt_len, payload_len; pkt_len = hv_pkt_len(hvs->recv_desc); if (pkt_len < HVS_HEADER_LEN) return -EIO; recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); payload_len = recv_buf->hdr.data_size; if (payload_len > pkt_len - HVS_HEADER_LEN || payload_len > HVS_MTU_SIZE) return -EIO; if (payload_len == 0) hvs->vsk->peer_shutdown |= SEND_SHUTDOWN; hvs->recv_data_len = payload_len; hvs->recv_data_off = 0; return 0; } static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg, size_t len, int flags) { struct hvsock *hvs = vsk->trans; bool need_refill = !hvs->recv_desc; struct hvs_recv_buf *recv_buf; u32 to_read; int ret; if (flags & MSG_PEEK) return -EOPNOTSUPP; if (need_refill) { hvs->recv_desc = hv_pkt_iter_first(hvs->chan); if (!hvs->recv_desc) return -ENOBUFS; ret = hvs_update_recv_data(hvs); if (ret) return ret; } recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); to_read = min_t(u32, len, hvs->recv_data_len); ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read); if (ret != 0) return ret; hvs->recv_data_len -= to_read; if (hvs->recv_data_len == 0) { hvs->recv_desc = hv_pkt_iter_next(hvs->chan, hvs->recv_desc); if (hvs->recv_desc) { ret = hvs_update_recv_data(hvs); if (ret) return ret; } } else { hvs->recv_data_off += to_read; } return to_read; } static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, size_t len) { struct hvsock *hvs = vsk->trans; struct vmbus_channel *chan = hvs->chan; struct hvs_send_buf *send_buf; ssize_t to_write, max_writable; ssize_t ret = 0; ssize_t bytes_written = 0; BUILD_BUG_ON(sizeof(*send_buf) != HV_HYP_PAGE_SIZE); send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL); if (!send_buf) return -ENOMEM; /* Reader(s) could be draining data from the channel as we write. * Maximize bandwidth, by iterating until the channel is found to be * full. */ while (len) { max_writable = hvs_channel_writable_bytes(chan); if (!max_writable) break; to_write = min_t(ssize_t, len, max_writable); to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE); /* memcpy_from_msg is safe for loop as it advances the offsets * within the message iterator. */ ret = memcpy_from_msg(send_buf->data, msg, to_write); if (ret < 0) goto out; ret = hvs_send_data(hvs->chan, send_buf, to_write); if (ret < 0) goto out; bytes_written += to_write; len -= to_write; } out: /* If any data has been sent, return that */ if (bytes_written) ret = bytes_written; kfree(send_buf); return ret; } static s64 hvs_stream_has_data(struct vsock_sock *vsk) { struct hvsock *hvs = vsk->trans; s64 ret; if (hvs->recv_data_len > 0) return 1; switch (hvs_channel_readable_payload(hvs->chan)) { case 1: ret = 1; break; case 0: vsk->peer_shutdown |= SEND_SHUTDOWN; ret = 0; break; default: /* -1 */ ret = 0; break; } return ret; } static s64 hvs_stream_has_space(struct vsock_sock *vsk) { struct hvsock *hvs = vsk->trans; return hvs_channel_writable_bytes(hvs->chan); } static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk) { return HVS_MTU_SIZE + 1; } static bool hvs_stream_is_active(struct vsock_sock *vsk) { struct hvsock *hvs = vsk->trans; return hvs->chan != NULL; } static bool hvs_stream_allow(u32 cid, u32 port) { if (cid == VMADDR_CID_HOST) return true; return false; } static int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable) { struct hvsock *hvs = vsk->trans; *readable = hvs_channel_readable(hvs->chan); return 0; } static int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable) { *writable = hvs_stream_has_space(vsk) > 0; return 0; } static int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target, struct vsock_transport_recv_notify_data *d) { return 0; } static int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target, struct vsock_transport_recv_notify_data *d) { return 0; } static int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target, struct vsock_transport_recv_notify_data *d) { return 0; } static int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target, ssize_t copied, bool data_read, struct vsock_transport_recv_notify_data *d) { return 0; } static int hvs_notify_send_init(struct vsock_sock *vsk, struct vsock_transport_send_notify_data *d) { return 0; } static int hvs_notify_send_pre_block(struct vsock_sock *vsk, struct vsock_transport_send_notify_data *d) { return 0; } static int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk, struct vsock_transport_send_notify_data *d) { return 0; } static int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, struct vsock_transport_send_notify_data *d) { return 0; } static int hvs_notify_set_rcvlowat(struct vsock_sock *vsk, int val) { return -EOPNOTSUPP; } static struct vsock_transport hvs_transport = { .module = THIS_MODULE, .get_local_cid = hvs_get_local_cid, .init = hvs_sock_init, .destruct = hvs_destruct, .release = hvs_release, .connect = hvs_connect, .shutdown = hvs_shutdown, .dgram_bind = hvs_dgram_bind, .dgram_dequeue = hvs_dgram_dequeue, .dgram_enqueue = hvs_dgram_enqueue, .dgram_allow = hvs_dgram_allow, .stream_dequeue = hvs_stream_dequeue, .stream_enqueue = hvs_stream_enqueue, .stream_has_data = hvs_stream_has_data, .stream_has_space = hvs_stream_has_space, .stream_rcvhiwat = hvs_stream_rcvhiwat, .stream_is_active = hvs_stream_is_active, .stream_allow = hvs_stream_allow, .notify_poll_in = hvs_notify_poll_in, .notify_poll_out = hvs_notify_poll_out, .notify_recv_init = hvs_notify_recv_init, .notify_recv_pre_block = hvs_notify_recv_pre_block, .notify_recv_pre_dequeue = hvs_notify_recv_pre_dequeue, .notify_recv_post_dequeue = hvs_notify_recv_post_dequeue, .notify_send_init = hvs_notify_send_init, .notify_send_pre_block = hvs_notify_send_pre_block, .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue, .notify_send_post_enqueue = hvs_notify_send_post_enqueue, .notify_set_rcvlowat = hvs_notify_set_rcvlowat }; static bool hvs_check_transport(struct vsock_sock *vsk) { return vsk->transport == &hvs_transport; } static int hvs_probe(struct hv_device *hdev, const struct hv_vmbus_device_id *dev_id) { struct vmbus_channel *chan = hdev->channel; hvs_open_connection(chan); /* Always return success to suppress the unnecessary error message * in vmbus_probe(): on error the host will rescind the device in * 30 seconds and we can do cleanup at that time in * vmbus_onoffer_rescind(). */ return 0; } static void hvs_remove(struct hv_device *hdev) { struct vmbus_channel *chan = hdev->channel; vmbus_close(chan); } /* hv_sock connections can not persist across hibernation, and all the hv_sock * channels are forced to be rescinded before hibernation: see * vmbus_bus_suspend(). Here the dummy hvs_suspend() and hvs_resume() * are only needed because hibernation requires that every vmbus device's * driver should have a .suspend and .resume callback: see vmbus_suspend(). */ static int hvs_suspend(struct hv_device *hv_dev) { /* Dummy */ return 0; } static int hvs_resume(struct hv_device *dev) { /* Dummy */ return 0; } /* This isn't really used. See vmbus_match() and vmbus_probe() */ static const struct hv_vmbus_device_id id_table[] = { {}, }; static struct hv_driver hvs_drv = { .name = "hv_sock", .hvsock = true, .id_table = id_table, .probe = hvs_probe, .remove = hvs_remove, .suspend = hvs_suspend, .resume = hvs_resume, }; static int __init hvs_init(void) { int ret; if (vmbus_proto_version < VERSION_WIN10) return -ENODEV; ret = vmbus_driver_register(&hvs_drv); if (ret != 0) return ret; ret = vsock_core_register(&hvs_transport, VSOCK_TRANSPORT_F_G2H); if (ret) { vmbus_driver_unregister(&hvs_drv); return ret; } return 0; } static void __exit hvs_exit(void) { vsock_core_unregister(&hvs_transport); vmbus_driver_unregister(&hvs_drv); } module_init(hvs_init); module_exit(hvs_exit); MODULE_DESCRIPTION("Hyper-V Sockets"); MODULE_VERSION("1.0.0"); MODULE_LICENSE("GPL"); MODULE_ALIAS_NETPROTO(PF_VSOCK);