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-rw-r--r--net/vmw_vsock/hyperv_transport.c956
1 files changed, 956 insertions, 0 deletions
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
new file mode 100644
index 000000000..59c3e2697
--- /dev/null
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -0,0 +1,956 @@
+// 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_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,
+
+ .set_rcvlowat = hvs_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 int hvs_remove(struct hv_device *hdev)
+{
+ struct vmbus_channel *chan = hdev->channel;
+
+ vmbus_close(chan);
+
+ return 0;
+}
+
+/* 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-09 14:29:20 +0000