// 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 <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <net/sock.h>
#include <net/af_vsock.h>
#include <asm/hyperv-tlfs.h>
/* 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
* <cid, port> (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 <VmID, ServiceId> 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: <port>-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);
}
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);
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