Hyper-V Sockets (hv_sock) supplies a byte-stream based communication mechanism between the host and the guest. It uses VMBus ringbuffer as the transportation layer. With hv_sock, applications between the host (Windows 10, Windows Server 2016 or newer) and the guest can talk with each other using the traditional socket APIs. More info about Hyper-V Sockets is available here: "Make your own integration services": https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/make-integration-service The patch implements the necessary support in Linux guest by introducing a new vsock transport for AF_VSOCK. Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Andy King <acking@xxxxxxxxxx> Cc: Dmitry Torokhov <dtor@xxxxxxxxxx> Cc: George Zhang <georgezhang@xxxxxxxxxx> Cc: Jorgen Hansen <jhansen@xxxxxxxxxx> Cc: Reilly Grant <grantr@xxxxxxxxxx> Cc: Asias He <asias@xxxxxxxxxx> Cc: Stefan Hajnoczi <stefanha@xxxxxxxxxx> Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Cc: Cathy Avery <cavery@xxxxxxxxxx> Cc: Rolf Neugebauer <rolf.neugebauer@xxxxxxxxxx> Cc: Marcelo Cerri <marcelo.cerri@xxxxxxxxxxxxx> --- Changes in v2: fixed hvs_stream_allow() for cid and the comments Thanks Stefan Hajnoczi! added proper locking when using vsock_enqueue_accept() Thanks Stefan Hajnoczi and Jorgen Hansen! The previous v1 patch is not needed any more: [PATCH net-next 2/3] vsock: fix vsock_dequeue/enqueue_accept race Another previous v1 patch is being discussed in another thread: vsock: only load vmci transport on VMware hypervisor by default Changes in v3 (addressed David Millers's comments): used better naming: VMBUS_PKT_TRAILER_SIZE better handled fin_sent: removed atomic removed "inline" tags better handled uuid service_id assignments: avoid pointers MAINTAINERS | 1 + net/vmw_vsock/Kconfig | 12 + net/vmw_vsock/Makefile | 3 + net/vmw_vsock/hyperv_transport.c | 904 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 920 insertions(+) create mode 100644 net/vmw_vsock/hyperv_transport.c diff --git a/MAINTAINERS b/MAINTAINERS index 2db0f8c..dae0573 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6279,6 +6279,7 @@ F: drivers/net/hyperv/ F: drivers/scsi/storvsc_drv.c F: drivers/uio/uio_hv_generic.c F: drivers/video/fbdev/hyperv_fb.c +F: net/vmw_vsock/hyperv_transport.c F: include/linux/hyperv.h F: tools/hv/ F: Documentation/ABI/stable/sysfs-bus-vmbus diff --git a/net/vmw_vsock/Kconfig b/net/vmw_vsock/Kconfig index a7ae09d..3f52929 100644 --- a/net/vmw_vsock/Kconfig +++ b/net/vmw_vsock/Kconfig @@ -46,3 +46,15 @@ config VIRTIO_VSOCKETS_COMMON This option is selected by any driver which needs to access the virtio_vsock. The module will be called vmw_vsock_virtio_transport_common. + +config HYPERV_VSOCKETS + tristate "Hyper-V transport for Virtual Sockets" + depends on VSOCKETS && HYPERV + help + This module implements a Hyper-V transport for Virtual Sockets. + + Enable this transport if your Virtual Machine host supports Virtual + Sockets over Hyper-V VMBus. + + To compile this driver as a module, choose M here: the module will be + called hv_sock. If unsure, say N. diff --git a/net/vmw_vsock/Makefile b/net/vmw_vsock/Makefile index 09fc2eb..e63d574 100644 --- a/net/vmw_vsock/Makefile +++ b/net/vmw_vsock/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_VSOCKETS) += vsock.o obj-$(CONFIG_VMWARE_VMCI_VSOCKETS) += vmw_vsock_vmci_transport.o obj-$(CONFIG_VIRTIO_VSOCKETS) += vmw_vsock_virtio_transport.o obj-$(CONFIG_VIRTIO_VSOCKETS_COMMON) += vmw_vsock_virtio_transport_common.o +obj-$(CONFIG_HYPERV_VSOCKETS) += hv_sock.o vsock-y += af_vsock.o af_vsock_tap.o vsock_addr.o @@ -11,3 +12,5 @@ vmw_vsock_vmci_transport-y += vmci_transport.o vmci_transport_notify.o \ vmw_vsock_virtio_transport-y += virtio_transport.o vmw_vsock_virtio_transport_common-y += virtio_transport_common.o + +hv_sock-y += hyperv_transport.o diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c new file mode 100644 index 0000000..14ed5a3 --- /dev/null +++ b/net/vmw_vsock/hyperv_transport.c @@ -0,0 +1,904 @@ +/* + * 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. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/hyperv.h> +#include <net/sock.h> +#include <net/af_vsock.h> + +/* The host side's design of the feature requires 6 exact 4KB pages for + * recv/send rings respectively -- this is suboptimal considering memory + * consumption, however unluckily we have to live with it, before the + * host comes up with a better design in the future. + */ +#define PAGE_SIZE_4K 4096 +#define RINGBUFFER_HVS_RCV_SIZE (PAGE_SIZE_4K * 6) +#define RINGBUFFER_HVS_SND_SIZE (PAGE_SIZE_4K * 6) + +/* The MTU is 16KB per the host side's design */ +#define HVS_MTU_SIZE (1024 * 16) + +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 small size, i.e. HVS_SEND_BUF_SIZE, to minimize the dynamically-allocated + * buffer, because tests show there is no significant performance difference. + * + * 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 (PAGE_SIZE_4K - 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) + +union hvs_service_id { + uuid_le srv_id; + + struct { + unsigned int svm_port; + unsigned char b[sizeof(uuid_le) - sizeof(unsigned int)]; + }; +}; + +/* Per-socket state (accessed via vsk->trans) */ +struct hvsock { + struct vsock_sock *vsk; + + uuid_le vm_srv_id; + uuid_le 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, and the "port" must be in * + * this range [0, 0x7FFFFFFF]. * + **************************************************************************** + * + * 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. + * + * From the perspective of Linux VM: + * 1. the local ephemeral port (i.e. the local auto-bound port when we call + * connect() without explicit bind()) is generated by __vsock_bind_stream(), + * and the range is [1024, 0xFFFFFFFF). + * 2. the remote ephemeral port (i.e. the auto-generated remote port for + * a connect request initiated by the host's connect()) is generated by + * hvs_remote_addr_init() and the range is [0x80000000, 0xFFFFFFFF). + */ + +#define MAX_LISTEN_PORT ((u32)0x7FFFFFFF) +#define MAX_VM_LISTEN_PORT MAX_LISTEN_PORT +#define MAX_HOST_LISTEN_PORT MAX_LISTEN_PORT +#define MIN_HOST_EPHEMERAL_PORT (MAX_HOST_LISTEN_PORT + 1) + +/* 00000000-facb-11e6-bd58-64006a7986d3 */ +static const uuid_le srv_id_template = + UUID_LE(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58, + 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3); + +static bool is_valid_srv_id(const uuid_le *id) +{ + return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(uuid_le) - 4); +} + +static unsigned int get_port_by_srv_id(const uuid_le *svr_id) +{ + return *((unsigned int *)svr_id); +} + +static void hvs_addr_init(struct sockaddr_vm *addr, const uuid_le *svr_id) +{ + unsigned int port = get_port_by_srv_id(svr_id); + + vsock_addr_init(addr, VMADDR_CID_ANY, port); +} + +static void hvs_remote_addr_init(struct sockaddr_vm *remote, + struct sockaddr_vm *local) +{ + static u32 host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT; + struct sock *sk; + + vsock_addr_init(remote, VMADDR_CID_ANY, VMADDR_PORT_ANY); + + while (1) { + /* Wrap around ? */ + if (host_ephemeral_port < MIN_HOST_EPHEMERAL_PORT || + host_ephemeral_port == VMADDR_PORT_ANY) + host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT; + + remote->svm_port = host_ephemeral_port++; + + sk = vsock_find_connected_socket(remote, local); + if (!sk) { + /* Found an available ephemeral port */ + return; + } + + /* Release refcnt got in vsock_find_connected_socket */ + sock_put(sk); + } +} + +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)); + + /* See hvs_stream_has_space(): we must make sure the host has seen + * the new pending send size, before we can re-check the writable + * bytes. + */ + virt_mb(); +} + +static void hvs_clear_channel_pending_send_size(struct vmbus_channel *chan) +{ + set_channel_pending_send_size(chan, 0); + + /* Ditto */ + 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 hvs_send_buf *send_buf, size_t to_write) +{ + send_buf->hdr.pkt_type = 1; + send_buf->hdr.data_size = to_write; + return vmbus_sendpacket(chan, &send_buf->hdr, + sizeof(send_buf->hdr) + to_write, + 0, VM_PKT_DATA_INBAND, 0); +} + +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); + + /* See hvs_stream_has_space(): when we reach here, the writable bytes + * may be already less than HVS_PKT_LEN(HVS_SEND_BUF_SIZE). + */ + if (hv_get_bytes_to_write(&chan->outbound) > 0) + sk->sk_write_space(sk); +} + +static void hvs_close_connection(struct vmbus_channel *chan) +{ + struct sock *sk = get_per_channel_state(chan); + struct vsock_sock *vsk = vsock_sk(sk); + + sk->sk_state = SS_UNCONNECTED; + sock_set_flag(sk, SOCK_DONE); + vsk->peer_shutdown |= SEND_SHUTDOWN | RCV_SHUTDOWN; + + sk->sk_state_change(sk); +} + +static void hvs_open_connection(struct vmbus_channel *chan) +{ + uuid_le *if_instance, *if_type; + unsigned char conn_from_host; + + struct sockaddr_vm addr; + struct sock *sk, *new = NULL; + struct vsock_sock *vnew; + struct hvsock *hvs, *hvs_new; + int ret; + + 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]; + + /* The host or the VM should only listen on a port in + * [0, MAX_LISTEN_PORT] + */ + if (!is_valid_srv_id(if_type) || + get_port_by_srv_id(if_type) > MAX_LISTEN_PORT) + return; + + hvs_addr_init(&addr, conn_from_host ? if_type : if_instance); + sk = vsock_find_bound_socket(&addr); + if (!sk) + return; + + if ((conn_from_host && sk->sk_state != VSOCK_SS_LISTEN) || + (!conn_from_host && sk->sk_state != SS_CONNECTING)) + goto out; + + if (conn_from_host) { + if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) + goto out; + + new = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL, + sk->sk_type, 0); + if (!new) + goto out; + + new->sk_state = SS_CONNECTING; + vnew = vsock_sk(new); + 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); + ret = vmbus_open(chan, RINGBUFFER_HVS_SND_SIZE, + RINGBUFFER_HVS_RCV_SIZE, 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); + vmbus_set_chn_rescind_callback(chan, hvs_close_connection); + + if (conn_from_host) { + new->sk_state = SS_CONNECTED; + sk->sk_ack_backlog++; + + hvs_addr_init(&vnew->local_addr, if_type); + hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr); + + hvs_new->vm_srv_id = *if_type; + hvs_new->host_srv_id = *if_instance; + + vsock_insert_connected(vnew); + + lock_sock(sk); + vsock_enqueue_accept(sk, new); + release_sock(sk); + } else { + sk->sk_state = SS_CONNECTED; + 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); +} + +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; + + hvs = kzalloc(sizeof(*hvs), GFP_KERNEL); + if (!hvs) + return -ENOMEM; + + vsk->trans = hvs; + hvs->vsk = vsk; + + 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 int hvs_shutdown(struct vsock_sock *vsk, int mode) +{ + struct sock *sk = sk_vsock(vsk); + struct vmpipe_proto_header hdr; + struct hvs_send_buf *send_buf; + struct hvsock *hvs; + + if (!(mode & SEND_SHUTDOWN)) + return 0; + + lock_sock(sk); + + hvs = vsk->trans; + if (hvs->fin_sent) + goto out; + + send_buf = (struct hvs_send_buf *)&hdr; + + /* It can't fail: see hvs_channel_writable_bytes(). */ + (void)hvs_send_data(hvs->chan, send_buf, 0); + + hvs->fin_sent = true; +out: + release_sock(sk); + return 0; +} + +static void hvs_release(struct vsock_sock *vsk) +{ + struct hvsock *hvs = vsk->trans; + struct vmbus_channel *chan = hvs->chan; + + if (chan) + hvs_shutdown(vsk, RCV_SHUTDOWN | SEND_SHUTDOWN); + + 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 payload_len; + + recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); + payload_len = recv_buf->hdr.data_size; + + if (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); + 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, ret; + + BUILD_BUG_ON(sizeof(*send_buf) != PAGE_SIZE_4K); + + send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL); + if (!send_buf) + return -ENOMEM; + + max_writable = hvs_channel_writable_bytes(chan); + to_write = min_t(ssize_t, len, max_writable); + to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE); + + 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; + + ret = to_write; +out: + 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; + struct vmbus_channel *chan = hvs->chan; + s64 ret; + + ret = hvs_channel_writable_bytes(chan); + if (ret > 0) { + hvs_clear_channel_pending_send_size(chan); + } else { + /* See hvs_channel_cb() */ + hvs_set_channel_pending_send_size(chan); + + /* Re-check the writable bytes to avoid race */ + ret = hvs_channel_writable_bytes(chan); + if (ret > 0) + hvs_clear_channel_pending_send_size(chan); + } + + return ret; +} + +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) +{ + /* The host's port range [MIN_HOST_EPHEMERAL_PORT, 0xFFFFFFFF) is + * reserved as ephemeral ports, which are used as the host's ports + * when the host initiates connections. + * + * Perform this check in the guest so an immediate error is produced + * instead of a timeout. + */ + if (port > MAX_HOST_LISTEN_PORT) + return false; + + 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 void hvs_set_buffer_size(struct vsock_sock *vsk, u64 val) +{ + /* Ignored. */ +} + +static void hvs_set_min_buffer_size(struct vsock_sock *vsk, u64 val) +{ + /* Ignored. */ +} + +static void hvs_set_max_buffer_size(struct vsock_sock *vsk, u64 val) +{ + /* Ignored. */ +} + +static u64 hvs_get_buffer_size(struct vsock_sock *vsk) +{ + return -ENOPROTOOPT; +} + +static u64 hvs_get_min_buffer_size(struct vsock_sock *vsk) +{ + return -ENOPROTOOPT; +} + +static u64 hvs_get_max_buffer_size(struct vsock_sock *vsk) +{ + return -ENOPROTOOPT; +} + +static struct vsock_transport hvs_transport = { + .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_buffer_size = hvs_set_buffer_size, + .set_min_buffer_size = hvs_set_min_buffer_size, + .set_max_buffer_size = hvs_set_max_buffer_size, + .get_buffer_size = hvs_get_buffer_size, + .get_min_buffer_size = hvs_get_min_buffer_size, + .get_max_buffer_size = hvs_get_max_buffer_size, +}; + +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; +} + +/* 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, +}; + +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_init(&hvs_transport); + if (ret) { + vmbus_driver_unregister(&hvs_drv); + return ret; + } + + return 0; +} + +static void __exit hvs_exit(void) +{ + vsock_core_exit(); + 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); -- 2.7.4 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
