VSOCK control notifications for VMCI Stream Sockets protocol.

Signed-off-by: George Zhang <georgezh...@vmware.com>
Acked-by: Andy king <ack...@vmware.com>
Acked-by: Dmitry Torokhov <d...@vmware.com>
---
 net/vmw_vsock/notify.c |  675 ++++++++++++++++++++++++++++++++++++++++++++++++
 net/vmw_vsock/notify.h |  124 +++++++++
 2 files changed, 799 insertions(+), 0 deletions(-)
 create mode 100644 net/vmw_vsock/notify.c
 create mode 100644 net/vmw_vsock/notify.h

diff --git a/net/vmw_vsock/notify.c b/net/vmw_vsock/notify.c
new file mode 100644
index 0000000..23bad8b
--- /dev/null
+++ b/net/vmw_vsock/notify.c
@@ -0,0 +1,675 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2009-2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that 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/types.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <net/sock.h>
+
+#include "notify.h"
+#include "af_vsock.h"
+
+#define PKT_FIELD(vsk, field_name) ((vsk)->notify.pkt.field_name)
+
+#define VSOCK_MAX_DGRAM_RESENDS       10
+
+static bool vsock_vmci_notify_waiting_write(struct vsock_vmci_sock *vsk)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       bool retval;
+       u64 notify_limit;
+
+       if (!PKT_FIELD(vsk, peer_waiting_write))
+               return false;
+
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+       /* When the sender blocks, we take that as a sign that the sender is
+        * faster than the receiver. To reduce the transmit rate of the sender,
+        * we delay the sending of the read notification by decreasing the
+        * write_notify_window. The notification is delayed until the number of
+        * bytes used in the queue drops below the write_notify_window.
+        */
+
+       if (!PKT_FIELD(vsk, peer_waiting_write_detected)) {
+               PKT_FIELD(vsk, peer_waiting_write_detected) = true;
+               if (PKT_FIELD(vsk, write_notify_window) < PAGE_SIZE) {
+                       PKT_FIELD(vsk, write_notify_window) =
+                           PKT_FIELD(vsk, write_notify_min_window);
+               } else {
+                       PKT_FIELD(vsk, write_notify_window) -= PAGE_SIZE;
+                       if (PKT_FIELD(vsk, write_notify_window) <
+                           PKT_FIELD(vsk, write_notify_min_window))
+                               PKT_FIELD(vsk, write_notify_window) =
+                                   PKT_FIELD(vsk, write_notify_min_window);
+
+               }
+       }
+       notify_limit = vsk->consume_size - PKT_FIELD(vsk, write_notify_window);
+#else
+       notify_limit = 0;
+#endif
+
+       /* For now we ignore the wait information and just see if the free
+        * space exceeds the notify limit.  Note that improving this function
+        * to be more intelligent will not require a protocol change and will
+        * retain compatibility between endpoints with mixed versions of this
+        * function.
+        *
+        * The notify_limit is used to delay notifications in the case where
+        * flow control is enabled. Below the test is expressed in terms of
+        * free space in the queue: if free_space > ConsumeSize -
+        * write_notify_window then notify An alternate way of expressing this
+        * is to rewrite the expression to use the data ready in the receive
+        * queue: if write_notify_window > bufferReady then notify as
+        * free_space == ConsumeSize - bufferReady.
+        */
+       retval = vmci_qpair_consume_free_space(vsk->qpair) > notify_limit;
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+       if (retval) {
+               /*
+                * Once we notify the peer, we reset the detected flag so the
+                * next wait will again cause a decrease in the window size.
+                */
+
+               PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+       }
+#endif
+       return retval;
+#else
+       return true;
+#endif
+}
+
+static bool vsock_vmci_notify_waiting_read(struct vsock_vmci_sock *vsk)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       if (!PKT_FIELD(vsk, peer_waiting_read))
+               return false;
+
+       /* For now we ignore the wait information and just see if there is any
+        * data for our peer to read.  Note that improving this function to be
+        * more intelligent will not require a protocol change and will retain
+        * compatibility between endpoints with mixed versions of this
+        * function.
+        */
+       return vmci_qpair_produce_buf_ready(vsk->qpair) > 0;
+#else
+       return true;
+#endif
+}
+
+static void
+vsock_vmci_handle_waiting_read(struct sock *sk,
+                              struct vsock_packet *pkt,
+                              bool bottom_half,
+                              struct sockaddr_vm *dst,
+                              struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       struct vsock_vmci_sock *vsk;
+
+       vsk = vsock_sk(sk);
+
+       PKT_FIELD(vsk, peer_waiting_read) = true;
+       memcpy(&PKT_FIELD(vsk, peer_waiting_read_info), &pkt->u.wait,
+              sizeof(PKT_FIELD(vsk, peer_waiting_read_info)));
+
+       if (vsock_vmci_notify_waiting_read(vsk)) {
+               bool sent;
+
+               if (bottom_half)
+                       sent = VSOCK_SEND_WROTE_BH(dst, src) > 0;
+               else
+                       sent = VSOCK_SEND_WROTE(sk) > 0;
+
+               if (sent)
+                       PKT_FIELD(vsk, peer_waiting_read) = false;
+
+       }
+#endif
+}
+
+static void
+vsock_vmci_handle_waiting_write(struct sock *sk,
+                               struct vsock_packet *pkt,
+                               bool bottom_half,
+                               struct sockaddr_vm *dst,
+                               struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       struct vsock_vmci_sock *vsk;
+
+       vsk = vsock_sk(sk);
+
+       PKT_FIELD(vsk, peer_waiting_write) = true;
+       memcpy(&PKT_FIELD(vsk, peer_waiting_write_info), &pkt->u.wait,
+              sizeof(PKT_FIELD(vsk, peer_waiting_write_info)));
+
+       if (vsock_vmci_notify_waiting_write(vsk)) {
+               bool sent;
+
+               if (bottom_half)
+                       sent = VSOCK_SEND_READ_BH(dst, src) > 0;
+               else
+                       sent = VSOCK_SEND_READ(sk) > 0;
+
+               if (sent)
+                       PKT_FIELD(vsk, peer_waiting_write) = false;
+
+       }
+#endif
+}
+
+static void
+vsock_vmci_handle_read(struct sock *sk,
+                      struct vsock_packet *pkt,
+                      bool bottom_half,
+                      struct sockaddr_vm *dst, struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       struct vsock_vmci_sock *vsk;
+
+       vsk = vsock_sk(sk);
+       PKT_FIELD(vsk, sent_waiting_write) = false;
+#endif
+
+       sk->sk_write_space(sk);
+}
+
+static bool vsock_vmci_send_waiting_read(struct sock *sk, u64 room_needed)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       struct vsock_vmci_sock *vsk;
+       struct vsock_waiting_info waiting_info;
+       u64 tail;
+       u64 head;
+       u64 room_left;
+       bool ret;
+
+       vsk = vsock_sk(sk);
+
+       if (PKT_FIELD(vsk, sent_waiting_read))
+               return true;
+
+       if (PKT_FIELD(vsk, write_notify_window) < vsk->consume_size)
+               PKT_FIELD(vsk, write_notify_window) =
+                   min(PKT_FIELD(vsk, write_notify_window) + PAGE_SIZE,
+                       vsk->consume_size);
+
+       vmci_qpair_get_consume_indexes(vsk->qpair, &tail, &head);
+       room_left = vsk->consume_size - head;
+       if (room_needed >= room_left) {
+               waiting_info.offset = room_needed - room_left;
+               waiting_info.generation =
+                   PKT_FIELD(vsk, consume_q_generation) + 1;
+       } else {
+               waiting_info.offset = head + room_needed;
+               waiting_info.generation = PKT_FIELD(vsk, consume_q_generation);
+       }
+
+       ret = VSOCK_SEND_WAITING_READ(sk, &waiting_info) > 0;
+       if (ret)
+               PKT_FIELD(vsk, sent_waiting_read) = true;
+
+       return ret;
+#else
+       return true;
+#endif
+}
+
+static bool vsock_vmci_send_waiting_write(struct sock *sk, u64 room_needed)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       struct vsock_vmci_sock *vsk;
+       struct vsock_waiting_info waiting_info;
+       u64 tail;
+       u64 head;
+       u64 room_left;
+       bool ret;
+
+       vsk = vsock_sk(sk);
+
+       if (PKT_FIELD(vsk, sent_waiting_write))
+               return true;
+
+       vmci_qpair_get_produce_indexes(vsk->qpair, &tail, &head);
+       room_left = vsk->produce_size - tail;
+       if (room_needed + 1 >= room_left) {
+               /* Wraps around to current generation. */
+               waiting_info.offset = room_needed + 1 - room_left;
+               waiting_info.generation = PKT_FIELD(vsk, produce_q_generation);
+       } else {
+               waiting_info.offset = tail + room_needed + 1;
+               waiting_info.generation =
+                   PKT_FIELD(vsk, produce_q_generation) - 1;
+       }
+
+       ret = VSOCK_SEND_WAITING_WRITE(sk, &waiting_info) > 0;
+       if (ret)
+               PKT_FIELD(vsk, sent_waiting_write) = true;
+
+       return ret;
+#else
+       return true;
+#endif
+}
+
+static int vsock_vmci_send_read_notification(struct sock *sk)
+{
+       struct vsock_vmci_sock *vsk;
+       bool sent_read;
+       unsigned int retries;
+       int err;
+
+       vsk = vsock_sk(sk);
+       sent_read = false;
+       retries = 0;
+       err = 0;
+
+       if (vsock_vmci_notify_waiting_write(vsk)) {
+               /* Notify the peer that we have read, retrying the send on
+                * failure up to our maximum value.  XXX For now we just log
+                * the failure, but later we should schedule a work item to
+                * handle the resend until it succeeds.  That would require
+                * keeping track of work items in the vsk and cleaning them up
+                * upon socket close.
+                */
+               while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
+                      !sent_read && retries < VSOCK_MAX_DGRAM_RESENDS) {
+                       err = VSOCK_SEND_READ(sk);
+                       if (err >= 0)
+                               sent_read = true;
+
+                       retries++;
+               }
+
+               if (retries >= VSOCK_MAX_DGRAM_RESENDS)
+                       pr_err("%p unable to send read notify to peer\n", sk);
+               else
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+                       PKT_FIELD(vsk, peer_waiting_write) = false;
+#endif
+
+       }
+       return err;
+}
+
+static void
+vsock_vmci_handle_wrote(struct sock *sk,
+                       struct vsock_packet *pkt,
+                       bool bottom_half,
+                       struct sockaddr_vm *dst, struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       struct vsock_vmci_sock *vsk;
+
+       vsk = vsock_sk(sk);
+       PKT_FIELD(vsk, sent_waiting_read) = false;
+#endif
+
+       sk->sk_data_ready(sk, 0);
+}
+
+static void vsock_vmci_notify_pkt_socket_init(struct sock *sk)
+{
+       struct vsock_vmci_sock *vsk;
+       vsk = vsock_sk(sk);
+
+       PKT_FIELD(vsk, write_notify_window) = PAGE_SIZE;
+       PKT_FIELD(vsk, write_notify_min_window) = PAGE_SIZE;
+       PKT_FIELD(vsk, peer_waiting_read) = false;
+       PKT_FIELD(vsk, peer_waiting_write) = false;
+       PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+       PKT_FIELD(vsk, sent_waiting_read) = false;
+       PKT_FIELD(vsk, sent_waiting_write) = false;
+       PKT_FIELD(vsk, produce_q_generation) = 0;
+       PKT_FIELD(vsk, consume_q_generation) = 0;
+
+       memset(&PKT_FIELD(vsk, peer_waiting_read_info), 0,
+              sizeof(PKT_FIELD(vsk, peer_waiting_read_info)));
+       memset(&PKT_FIELD(vsk, peer_waiting_write_info), 0,
+              sizeof(PKT_FIELD(vsk, peer_waiting_write_info)));
+}
+
+static void vsock_vmci_notify_pkt_socket_destruct(struct sock *sk)
+{
+       return;
+}
+
+static int
+vsock_vmci_notify_pkt_poll_in(struct sock *sk,
+                             size_t target, bool *data_ready_now)
+{
+       struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+       if (vsock_vmci_stream_has_data(vsk)) {
+               *data_ready_now = true;
+       } else {
+               /* We can't read right now because there is nothing in the
+                * queue. Ask for notifications when there is something to
+                * read.
+                */
+               if (sk->sk_state == SS_CONNECTED) {
+                       if (!vsock_vmci_send_waiting_read(sk, 1))
+                               return -1;
+
+               }
+               *data_ready_now = false;
+       }
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_poll_out(struct sock *sk,
+                              size_t target, bool *space_avail_now)
+{
+       s64 produce_q_free_space;
+       struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+       produce_q_free_space = vsock_vmci_stream_has_space(vsk);
+       if (produce_q_free_space > 0) {
+               *space_avail_now = true;
+               return 0;
+       } else if (produce_q_free_space == 0) {
+               /* This is a connected socket but we can't currently send data.
+                * Notify the peer that we are waiting if the queue is full. We
+                * only send a waiting write if the queue is full because
+                * otherwise we end up in an infinite WAITING_WRITE, READ,
+                * WAITING_WRITE, READ, etc. loop. Treat failing to send the
+                * notification as a socket error, passing that back through
+                * the mask.
+                */
+               if (!vsock_vmci_send_waiting_write(sk, 1))
+                       return -1;
+
+               *space_avail_now = false;
+       }
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_recv_init(struct sock *sk,
+                               size_t target,
+                               struct vsock_vmci_recv_notify_data *data)
+{
+       struct vsock_vmci_sock *vsk;
+
+       vsk = vsock_sk(sk);
+
+#ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY
+       data->consume_head = 0;
+       data->produce_tail = 0;
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+       data->notify_on_block = false;
+
+       if (PKT_FIELD(vsk, write_notify_min_window) < target + 1) {
+               PKT_FIELD(vsk, write_notify_min_window) = target + 1;
+               if (PKT_FIELD(vsk, write_notify_window) <
+                   PKT_FIELD(vsk, write_notify_min_window)) {
+                       /* If the current window is smaller than the new
+                        * minimal window size, we need to reevaluate whether
+                        * we need to notify the sender. If the number of ready
+                        * bytes are smaller than the new window, we need to
+                        * send a notification to the sender before we block.
+                        */
+
+                       PKT_FIELD(vsk, write_notify_window) =
+                           PKT_FIELD(vsk, write_notify_min_window);
+                       data->notify_on_block = true;
+               }
+       }
+#endif
+#endif
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_recv_pre_block(struct sock *sk,
+                                    size_t target,
+                                    struct vsock_vmci_recv_notify_data *data)
+{
+       int err = 0;
+
+       /* Notify our peer that we are waiting for data to read. */
+       if (!vsock_vmci_send_waiting_read(sk, target)) {
+               err = -EHOSTUNREACH;
+               return err;
+       }
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+       if (data->notify_on_block) {
+               err = vsock_vmci_send_read_notification(sk);
+               if (err < 0)
+                       return err;
+
+               data->notify_on_block = false;
+       }
+#endif
+
+       return err;
+}
+
+static int
+vsock_vmci_notify_pkt_recv_pre_dequeue(struct sock *sk,
+                                      size_t target,
+                                      struct vsock_vmci_recv_notify_data *data)
+{
+       struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+       /* Now consume up to len bytes from the queue.  Note that since we have
+        * the socket locked we should copy at least ready bytes.
+        */
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       vmci_qpair_get_consume_indexes(vsk->qpair,
+                                      &data->produce_tail,
+                                      &data->consume_head);
+#endif
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_recv_post_dequeue(struct sock *sk,
+                               size_t target,
+                               ssize_t copied,
+                               bool data_read,
+                               struct vsock_vmci_recv_notify_data *data)
+{
+       struct vsock_vmci_sock *vsk;
+       int err;
+
+       vsk = vsock_sk(sk);
+       err = 0;
+
+       if (data_read) {
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+               /* Detect a wrap-around to maintain queue generation.  Note
+                * that this is safe since we hold the socket lock across the
+                * two queue pair operations.
+                */
+               if (copied >= vsk->consume_size - data->consume_head)
+                       PKT_FIELD(vsk, consume_q_generation)++;
+
+#endif
+
+               err = vsock_vmci_send_read_notification(sk);
+               if (err < 0)
+                       return err;
+
+       }
+       return err;
+}
+
+static int
+vsock_vmci_notify_pkt_send_init(struct sock *sk,
+                               struct vsock_vmci_send_notify_data *data)
+{
+#ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY
+       data->consume_head = 0;
+       data->produce_tail = 0;
+#endif
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_send_pre_block(struct sock *sk,
+                                    struct vsock_vmci_send_notify_data *data)
+{
+       /* Notify our peer that we are waiting for room to write. */
+       if (!vsock_vmci_send_waiting_write(sk, 1))
+               return -EHOSTUNREACH;
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_send_pre_enqueue(struct sock *sk,
+                                      struct vsock_vmci_send_notify_data *data)
+{
+       struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       vmci_qpair_get_produce_indexes(vsk->qpair,
+                                      &data->produce_tail,
+                                      &data->consume_head);
+#endif
+
+       return 0;
+}
+
+static int
+vsock_vmci_notify_pkt_send_post_enqueue(struct sock *sk,
+                               ssize_t written,
+                               struct vsock_vmci_send_notify_data *data)
+{
+       int err = 0;
+       struct vsock_vmci_sock *vsk;
+       bool sent_wrote = false;
+       int retries = 0;
+
+       vsk = vsock_sk(sk);
+
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+       /* Detect a wrap-around to maintain queue generation.  Note that this
+        * is safe since we hold the socket lock across the two queue pair
+        * operations.
+        */
+       if (written >= vsk->produce_size - data->produce_tail)
+               PKT_FIELD(vsk, produce_q_generation)++;
+
+#endif
+
+       if (vsock_vmci_notify_waiting_read(vsk)) {
+               /* Notify the peer that we have written, retrying the send on
+                * failure up to our maximum value. See the XXX comment for the
+                * corresponding piece of code in StreamRecvmsg() for potential
+                * improvements.
+                */
+               while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
+                      !sent_wrote && retries < VSOCK_MAX_DGRAM_RESENDS) {
+                       err = VSOCK_SEND_WROTE(sk);
+                       if (err >= 0)
+                               sent_wrote = true;
+
+                       retries++;
+               }
+
+               if (retries >= VSOCK_MAX_DGRAM_RESENDS) {
+                       pr_err("%p unable to send wrote notify to peer\n", sk);
+                       return err;
+               } else {
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+                       PKT_FIELD(vsk, peer_waiting_read) = false;
+#endif
+               }
+       }
+       return err;
+}
+
+static void
+vsock_vmci_notify_pkt_handle_pkt(struct sock *sk,
+                                struct vsock_packet *pkt,
+                                bool bottom_half,
+                                struct sockaddr_vm *dst,
+                                struct sockaddr_vm *src, bool *pkt_processed)
+{
+       bool processed = false;
+
+       switch (pkt->type) {
+       case VSOCK_PACKET_TYPE_WROTE:
+               vsock_vmci_handle_wrote(sk, pkt, bottom_half, dst, src);
+               processed = true;
+               break;
+       case VSOCK_PACKET_TYPE_READ:
+               vsock_vmci_handle_read(sk, pkt, bottom_half, dst, src);
+               processed = true;
+               break;
+       case VSOCK_PACKET_TYPE_WAITING_WRITE:
+               vsock_vmci_handle_waiting_write(sk, pkt, bottom_half, dst, src);
+               processed = true;
+               break;
+
+       case VSOCK_PACKET_TYPE_WAITING_READ:
+               vsock_vmci_handle_waiting_read(sk, pkt, bottom_half, dst, src);
+               processed = true;
+               break;
+       }
+
+       if (pkt_processed)
+               *pkt_processed = processed;
+
+}
+
+static void vsock_vmci_notify_pkt_process_request(struct sock *sk)
+{
+       struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+       PKT_FIELD(vsk, write_notify_window) = vsk->consume_size;
+       if (vsk->consume_size < PKT_FIELD(vsk, write_notify_min_window))
+               PKT_FIELD(vsk, write_notify_min_window) = vsk->consume_size;
+
+}
+
+static void vsock_vmci_notify_pkt_process_negotiate(struct sock *sk)
+{
+       struct vsock_vmci_sock *vsk = vsock_sk(sk);
+
+       PKT_FIELD(vsk, write_notify_window) = vsk->consume_size;
+       if (vsk->consume_size < PKT_FIELD(vsk, write_notify_min_window))
+               PKT_FIELD(vsk, write_notify_min_window) = vsk->consume_size;
+
+}
+
+/* Socket control packet based operations. */
+struct vsock_vmci_notify_ops vsock_vmci_notify_pkt_ops = {
+       vsock_vmci_notify_pkt_socket_init,
+       vsock_vmci_notify_pkt_socket_destruct,
+       vsock_vmci_notify_pkt_poll_in,
+       vsock_vmci_notify_pkt_poll_out,
+       vsock_vmci_notify_pkt_handle_pkt,
+       vsock_vmci_notify_pkt_recv_init,
+       vsock_vmci_notify_pkt_recv_pre_block,
+       vsock_vmci_notify_pkt_recv_pre_dequeue,
+       vsock_vmci_notify_pkt_recv_post_dequeue,
+       vsock_vmci_notify_pkt_send_init,
+       vsock_vmci_notify_pkt_send_pre_block,
+       vsock_vmci_notify_pkt_send_pre_enqueue,
+       vsock_vmci_notify_pkt_send_post_enqueue,
+       vsock_vmci_notify_pkt_process_request,
+       vsock_vmci_notify_pkt_process_negotiate,
+};
diff --git a/net/vmw_vsock/notify.h b/net/vmw_vsock/notify.h
new file mode 100644
index 0000000..dc52217
--- /dev/null
+++ b/net/vmw_vsock/notify.h
@@ -0,0 +1,124 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2009-2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#ifndef __NOTIFY_H__
+#define __NOTIFY_H__
+
+#include <linux/types.h>
+
+#include "vsock_common.h"
+#include "vsock_packet.h"
+
+/* Comment this out to compare with old protocol. */
+#define VSOCK_OPTIMIZATION_WAITING_NOTIFY 1
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+/* Comment this out to remove flow control for "new" protocol */
+#define VSOCK_OPTIMIZATION_FLOW_CONTROL 1
+#endif
+
+#define VSOCK_MAX_DGRAM_RESENDS       10
+
+#define NOTIFYCALLRET(vsk, rv, mod_fn, args...)                        \
+       do {                                                    \
+               if (vsk->notify_ops &&                          \
+                   vsk->notify_ops->mod_fn != NULL)            \
+                       rv = (vsk->notify_ops->mod_fn)(args);   \
+               else                                            \
+                       rv = 0;                                 \
+                                                               \
+       } while (0)
+
+#define NOTIFYCALL(vsk, mod_fn, args...)                       \
+       do {                                                    \
+               if (vsk->notify_ops &&                          \
+                   vsk->notify_ops->mod_fn != NULL)            \
+                       (vsk->notify_ops->mod_fn)(args);        \
+                                                               \
+       } while (0)
+
+struct vsock_vmci_notify_pkt {
+       u64 write_notify_window;
+       u64 write_notify_min_window;
+       bool peer_waiting_read;
+       bool peer_waiting_write;
+       bool peer_waiting_write_detected;
+       bool sent_waiting_read;
+       bool sent_waiting_write;
+       struct vsock_waiting_info peer_waiting_read_info;
+       struct vsock_waiting_info peer_waiting_write_info;
+       u64 produce_q_generation;
+       u64 consume_q_generation;
+};
+
+struct vsock_vmci_notify_pkt_q_state {
+       u64 write_notify_window;
+       u64 write_notify_min_window;
+       bool peer_waiting_write;
+       bool peer_waiting_write_detected;
+};
+
+union vsock_vmci_notify {
+       struct vsock_vmci_notify_pkt pkt;
+       struct vsock_vmci_notify_pkt_q_state pkt_q_state;
+};
+
+struct vsock_vmci_recv_notify_data {
+       u64 consume_head;
+       u64 produce_tail;
+       bool notify_on_block;
+};
+
+struct vsock_vmci_send_notify_data {
+       u64 consume_head;
+       u64 produce_tail;
+};
+
+/* Socket notification callbacks. */
+struct vsock_vmci_notify_ops {
+       void (*socket_init) (struct sock *sk);
+       void (*socket_destruct) (struct sock *sk);
+       int (*poll_in) (struct sock *sk, size_t target,
+                         bool *data_ready_now);
+       int (*poll_out) (struct sock *sk, size_t target,
+                          bool *space_avail_now);
+       void (*handle_notify_pkt) (struct sock *sk, struct vsock_packet *pkt,
+                                  bool bottom_half, struct sockaddr_vm *dst,
+                                  struct sockaddr_vm *src,
+                                  bool *pkt_processed);
+       int (*recv_init) (struct sock *sk, size_t target,
+                         struct vsock_vmci_recv_notify_data *data);
+       int (*recv_pre_block) (struct sock *sk, size_t target,
+                              struct vsock_vmci_recv_notify_data *data);
+       int (*recv_pre_dequeue) (struct sock *sk, size_t target,
+                                struct vsock_vmci_recv_notify_data *data);
+       int (*recv_post_dequeue) (struct sock *sk, size_t target,
+                                 ssize_t copied, bool data_read,
+                                 struct vsock_vmci_recv_notify_data *data);
+       int (*send_init) (struct sock *sk,
+                         struct vsock_vmci_send_notify_data *data);
+       int (*send_pre_block) (struct sock *sk,
+                              struct vsock_vmci_send_notify_data *data);
+       int (*send_pre_enqueue) (struct sock *sk,
+                                struct vsock_vmci_send_notify_data *data);
+       int (*send_post_enqueue) (struct sock *sk, ssize_t written,
+                                 struct vsock_vmci_send_notify_data *data);
+       void (*process_request) (struct sock *sk);
+       void (*process_negotiate) (struct sock *sk);
+};
+
+extern struct vsock_vmci_notify_ops vsock_vmci_notify_pkt_ops;
+extern struct vsock_vmci_notify_ops vsock_vmci_notify_pkt_q_state_ops;
+
+#endif /* __NOTIFY_H__ */

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