Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933036Ab2KESBU (ORCPT ); Mon, 5 Nov 2012 13:01:20 -0500 Received: from smtp-outbound-1.vmware.com ([208.91.2.12]:54302 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754551Ab2KESBO (ORCPT ); Mon, 5 Nov 2012 13:01:14 -0500 Subject: [PATCH 3/6] VSOCK: notification implementation. To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, georgezhang@vmware.com, virtualization@lists.linux-foundation.org From: George Zhang Cc: pv-drivers@vmware.com, vm-crosstalk@vmware.com, davem@davemloft.net, gregkh@linuxfoundation.org Date: Mon, 05 Nov 2012 10:01:14 -0800 Message-ID: <20121105180108.21472.39071.stgit@promb-2n-dhcp175.eng.vmware.com> In-Reply-To: <20121105175730.21472.99155.stgit@promb-2n-dhcp175.eng.vmware.com> References: <20121105175730.21472.99155.stgit@promb-2n-dhcp175.eng.vmware.com> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 29448 Lines: 1143 VSOCK control notifications for VMCI Stream Sockets protocol. Signed-off-by: George Zhang --- net/vmw_vsock/notify.c | 984 ++++++++++++++++++++++++++++++++++++++++++++++++ net/vmw_vsock/notify.h | 130 ++++++ 2 files changed, 1114 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..5c69c7c --- /dev/null +++ b/net/vmw_vsock/notify.c @@ -0,0 +1,984 @@ +/* + * 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. + */ + +/* + * notify.c -- + * + * Linux control notifications for the VMCI Stream Sockets protocol. + */ + +#include + +#include +#include /* for NULL */ +#include + +#include "notify.h" +#include "af_vsock.h" + +#define PKT_FIELD(vsk, field_name) \ + (vsk)->notify.pkt.field_name + +#define VSOCK_MAX_DGRAM_RESENDS 10 + +/* + * + * vsock_vmci_notify_waiting_write -- + * + * Determines if the conditions have been met to notify a waiting writer. + * + * Results: true if a notification should be sent, false otherwise. + * + * Side effects: None. + */ + +static bool vsock_vmci_notify_waiting_write(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 +} + +/* + * + * vsock_vmci_notify_waiting_read -- + * + * Determines if the conditions have been met to notify a waiting reader. + * + * Results: true if a notification should be sent, false otherwise. + * + * Side effects: None. + */ + +static bool vsock_vmci_notify_waiting_read(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 +} + +/* + * + * vsock_vmci_handle_waiting_read -- + * + * Handles an incoming waiting read message. + * + * Results: None. + * + * Side effects: May send a notification to the peer, may update socket's wait + * info structure. + */ + +static void +vsock_vmci_handle_waiting_read(struct sock *sk, + vsock_packet *pkt, + bool bottom_half, + struct sockaddr_vm *dst, struct sockaddr_vm *src) +{ +#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY) + 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 +} + +/* + * + * vsock_vmci_handle_waiting_write -- + * + * Handles an incoming waiting write message. + * + * Results: None. + * + * Side effects: May send a notification to the peer, may update socket's wait + * info structure. + */ + +static void +vsock_vmci_handle_waiting_write(struct sock *sk, + vsock_packet *pkt, + bool bottom_half, + struct sockaddr_vm *dst, + struct sockaddr_vm *src) +{ +#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY) + 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 +} + +/* + * + * vsock_vmci_handle_read -- + * + * Handles an incoming read message. + * + * Results: None. + * + * Side effects: None. + */ + +static void +vsock_vmci_handle_read(struct sock *sk, + vsock_packet *pkt, + bool bottom_half, + struct sockaddr_vm *dst, struct sockaddr_vm *src) +{ +#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY) + vsock_vmci_sock *vsk; + + vsk = vsock_sk(sk); + PKT_FIELD(vsk, sent_waiting_write) = false; +#endif + + sk->sk_write_space(sk); +} + +/* + * + * vsock_vmci_send_waiting_read -- + * + * Sends a waiting read notification to this socket's peer. + * + * Results: true if the datagram is sent successfully, false otherwise. + * + * Side effects: Our peer will notify us when there is data to read from our + * consume queue. + */ + +static bool vsock_vmci_send_waiting_read(struct sock *sk, u64 room_needed) +{ +#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY) + vsock_vmci_sock *vsk; + 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 +} + +/* + * + * vsock_vmci_send_waiting_write -- + * + * Sends a waiting write notification to this socket's peer. + * + * Results: true if the datagram is sent successfully or does not need to be + * sent. false otherwise. + * + * Side effects: Our peer will notify us when there is room to write in to our + * produce queue. + */ + +static bool vsock_vmci_send_waiting_write(struct sock *sk, u64 room_needed) +{ +#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY) + vsock_vmci_sock *vsk; + 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 +} + +/* + * + * vsock_vmci_send_read_notification -- + * + * Sends a read notification to this socket's peer. + * + * Results: >= 0 if the datagram is sent successfully, negative error value + * otherwise. + * + * Side effects: None. + */ + +static int vsock_vmci_send_read_notification(struct sock *sk) +{ + 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) + printk + ("%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; +} + +/* + * + * vsock_vmci_handle_wrote -- + * + * Handles an incoming wrote message. + * + * Results: None. + * + * Side effects: None. + */ + +static void +vsock_vmci_handle_wrote(struct sock *sk, + vsock_packet *pkt, + bool bottom_half, + struct sockaddr_vm *dst, struct sockaddr_vm *src) +{ +#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY) + vsock_vmci_sock *vsk; + + vsk = vsock_sk(sk); + PKT_FIELD(vsk, sent_waiting_read) = false; +#endif + + sk->sk_data_ready(sk, 0); +} + +/* + * + * vsock_vmci_notify_pkt_socket_init -- + * + * Function that is called after a socket is created and before any notify ops + * are used. + * + * Results: None. + * + * Side effects: None. + */ + +static void vsock_vmci_notify_pkt_socket_init(struct sock *sk) +{ + 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)); +} + +/* + * + * vsock_vmci_notify_pkt_socket_destruct -- + * + * Function that is called when the socket is being released. + * + * Results: None. + * + * Side effects: None. + */ + +static void vsock_vmci_notify_pkt_socket_destruct(struct sock *sk) +{ + return; +} + +/* + * + * vsock_vmci_notify_pkt_poll_in -- + * + * Called by the poll function to figure out if there is data to read and to + * setup future notifications if needed. Only called on sockets that aren't + * shutdown for recv. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_poll_in(struct sock *sk, + size_t target, bool *data_ready_now) +{ + 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; +} + +/* + * + * vsock_vmci_notify_pkt_poll_out + * + * Called by the poll function to figure out if there is space to write and to + * setup future notifications if needed. Only called on a connected socket that + * isn't shutdown for send. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_poll_out(struct sock *sk, + size_t target, bool *space_avail_now) +{ + s64 produce_q_free_space; + 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; +} + +/* + * + * vsock_vmci_notify_pkt_recv_init -- + * + * Called at the start of a stream recv call with the socket lock held. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_recv_init(struct sock *sk, + size_t target, + vsock_vmci_recv_notify_data *data) +{ + 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) { + ASSERT(target < vsk->consume_size); + 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; +} + +/* + * + * vsock_vmci_notify_pkt_recv_pre_block -- + * + * Called right before a socket is about to block with the socket lock held. + * The socket lock may have been released between the entry function and the + * preblock call. + * + * Note: This function may be called multiple times before the post block + * function is called. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_recv_pre_block(struct sock *sk, + size_t target, + 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; +} + +/* + * + * vsock_vmci_notify_pkt_recv_pre_dequeue -- + * + * Called right before we dequeue / peek data from a socket. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_recv_pre_dequeue(struct sock *sk, + size_t target, + vsock_vmci_recv_notify_data *data) +{ + 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; +} + +/* + * + * vsock_vmci_notify_pkt_recv_post_dequeue -- + * + * Called right after we dequeue / peek data from a socket. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_recv_post_dequeue(struct sock *sk, + size_t target, + ssize_t copied, + bool data_read, + vsock_vmci_recv_notify_data *data) +{ + 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; +} + +/* + * + * vsock_vmci_notify_pkt_send_init -- + * + * Called at the start of a stream send call with the socket lock held. + * + * Results: 0 on success. A negative error code on failure. + * + * Side effects: + */ + +static int +vsock_vmci_notify_pkt_send_init(struct sock *sk, + vsock_vmci_send_notify_data *data) +{ +#ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY + data->consume_head = 0; + data->produce_tail = 0; +#endif + + return 0; +} + +/* + * + * vsock_vmci_notify_pkt_send_pre_block -- + * + * Called right before a socket is about to block with the socket lock held. + * The socket lock may have been released between the entry function and the + * preblock call. + * + * Note: This function may be called multiple times before the post block + * function is called. + * + * Results. 0 on success. A negative error code on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_send_pre_block(struct sock *sk, + 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; +} + +/* + * + * vsock_vmci_notifySendPreEnqueue -- + * + * Called right before we Enqueue to a socket. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_send_pre_enqueue(struct sock *sk, + vsock_vmci_send_notify_data *data) +{ + 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; +} + +/* + * + * vsock_vmci_notifySendPostEnqueue -- + * + * Called right after we enqueue data to a socket. + * + * Results: 0 on success. Negative error on failure. + * + * Side effects: None. + */ + +static int +vsock_vmci_notify_pkt_send_post_enqueue(struct sock *sk, + ssize_t written, + vsock_vmci_send_notify_data *data) +{ + int err = 0; + 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) { + printk + (" %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; +} + +/* + * + * vsock_vmci_notify_pkt_handle_pkt + * + * Called when a notify packet is recieved for a socket in the connected state. + * Note this might be called from a bottom half. + * + * Results: None. + * + * Side effects: None. + */ + +static void +vsock_vmci_notify_pkt_handle_pkt(struct sock *sk, + 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; + +} + +/* + * + * vsock_vmci_notify_pkt_process_request + * + * Called near the end of process request. + * + * Results: None. + * + * Side effects: None. + */ + +static void vsock_vmci_notify_pkt_process_request(struct sock *sk) +{ + 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; + +} + +/* + * + * vsock_vmci_notify_pkt_process_negotiate + * + * Called near the end of process negotiate. + * + * Results: None. + * + * Side effects: None. + */ + +static void vsock_vmci_notify_pkt_process_negotiate(struct sock *sk) +{ + 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. */ +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..fe39442 --- /dev/null +++ b/net/vmw_vsock/notify.h @@ -0,0 +1,130 @@ +/* + * 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. + */ + +/* + * notify.h -- + * + * Notify functions for Linux VSocket module. + */ + +#ifndef __NOTIFY_H__ +#define __NOTIFY_H__ + +#include + +#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) + +typedef 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; + vsock_waiting_info peer_waiting_read_info; + vsock_waiting_info peer_waiting_write_info; + u64 produce_q_generation; + u64 consume_q_generation; +} vsock_vmci_notify_pkt; + +typedef 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; +} vsock_vmci_notify_pkt_q_state; + +typedef union vsock_vmci_notify { + vsock_vmci_notify_pkt pkt; + vsock_vmci_notify_pkt_q_state pkt_q_state; +} vsock_vmci_notify; + +typedef struct vsock_vmci_recv_notify_data { + u64 consume_head; + u64 produce_tail; + bool notify_on_block; +} vsock_vmci_recv_notify_data; + +typedef struct vsock_vmci_send_notify_data { + u64 consume_head; + u64 produce_tail; +} vsock_vmci_send_notify_data; + +/* Socket notification callbacks. */ +typedef 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, 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, + vsock_vmci_recv_notify_data *data); + int (*recv_pre_block) (struct sock *sk, size_t target, + vsock_vmci_recv_notify_data *data); + int (*recv_pre_dequeue) (struct sock *sk, size_t target, + vsock_vmci_recv_notify_data *data); + int (*recv_post_dequeue) (struct sock *sk, size_t target, + ssize_t copied, bool data_read, + vsock_vmci_recv_notify_data *data); + int (*send_init) (struct sock *sk, + vsock_vmci_send_notify_data *data); + int (*send_pre_block) (struct sock *sk, + vsock_vmci_send_notify_data *data); + int (*send_pre_enqueue) (struct sock *sk, + vsock_vmci_send_notify_data *data); + int (*send_post_enqueue) (struct sock *sk, ssize_t written, + vsock_vmci_send_notify_data *data); + void (*process_request) (struct sock *sk); + void (*process_negotiate) (struct sock *sk); +} vsock_vmci_notify_ops; + +extern vsock_vmci_notify_ops vsock_vmci_notify_pkt_ops; +extern vsock_vmci_notify_ops vsock_vmci_notify_pkt_q_state_ops; + +#endif /* __NOTIFY_H__ */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/