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6720c2b327
Current logic assumes that channel connections on the destination side are always established in the same order as the source and the first one will always be the main channel followed by the multifid or post-copy preemption channel. This may not be always true, as even if a channel has a connection established on the source side it can be in the pending state on the destination side and a newer connection can be established first. Basically causing out of order mapping of channels on the destination side. Currently, all channels except post-copy preempt send a magic number, this patch uses that magic number to decide the type of channel. This logic is applicable only for precopy(multifd) live migration, as mentioned, the post-copy preempt channel does not send any magic number. Also, tls live migrations already does tls handshake before creating other channels, so this issue is not possible with tls, hence this logic is avoided for tls live migrations. This patch uses read peek to check the magic number of channels so that current data/control stream management remains un-effected. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Suggested-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: manish.mishra <manish.mishra@nutanix.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
140 lines
3.8 KiB
C
140 lines
3.8 KiB
C
/*
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* QEMU live migration channel operations
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*
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* Copyright Red Hat, Inc. 2016
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*
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* Authors:
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* Daniel P. Berrange <berrange@redhat.com>
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "qemu/osdep.h"
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#include "channel.h"
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#include "tls.h"
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#include "migration.h"
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#include "qemu-file.h"
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#include "trace.h"
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#include "qapi/error.h"
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#include "io/channel-tls.h"
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#include "io/channel-socket.h"
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#include "qemu/yank.h"
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#include "yank_functions.h"
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/**
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* @migration_channel_process_incoming - Create new incoming migration channel
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*
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* Notice that TLS is special. For it we listen in a listener socket,
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* and then create a new client socket from the TLS library.
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*
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* @ioc: Channel to which we are connecting
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*/
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void migration_channel_process_incoming(QIOChannel *ioc)
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{
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MigrationState *s = migrate_get_current();
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Error *local_err = NULL;
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trace_migration_set_incoming_channel(
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ioc, object_get_typename(OBJECT(ioc)));
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if (migrate_channel_requires_tls_upgrade(ioc)) {
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migration_tls_channel_process_incoming(s, ioc, &local_err);
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} else {
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migration_ioc_register_yank(ioc);
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migration_ioc_process_incoming(ioc, &local_err);
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}
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if (local_err) {
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error_report_err(local_err);
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}
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}
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/**
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* @migration_channel_connect - Create new outgoing migration channel
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*
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* @s: Current migration state
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* @ioc: Channel to which we are connecting
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* @hostname: Where we want to connect
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* @error: Error indicating failure to connect, free'd here
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*/
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void migration_channel_connect(MigrationState *s,
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QIOChannel *ioc,
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const char *hostname,
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Error *error)
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{
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trace_migration_set_outgoing_channel(
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ioc, object_get_typename(OBJECT(ioc)), hostname, error);
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if (!error) {
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if (migrate_channel_requires_tls_upgrade(ioc)) {
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migration_tls_channel_connect(s, ioc, hostname, &error);
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if (!error) {
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/* tls_channel_connect will call back to this
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* function after the TLS handshake,
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* so we mustn't call migrate_fd_connect until then
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*/
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return;
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}
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} else {
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QEMUFile *f = qemu_file_new_output(ioc);
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migration_ioc_register_yank(ioc);
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qemu_mutex_lock(&s->qemu_file_lock);
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s->to_dst_file = f;
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qemu_mutex_unlock(&s->qemu_file_lock);
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}
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}
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migrate_fd_connect(s, error);
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error_free(error);
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}
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/**
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* @migration_channel_read_peek - Peek at migration channel, without
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* actually removing it from channel buffer.
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*
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* @ioc: the channel object
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* @buf: the memory region to read data into
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* @buflen: the number of bytes to read in @buf
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* @errp: pointer to a NULL-initialized error object
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*
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* Returns 0 if successful, returns -1 and sets @errp if fails.
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*/
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int migration_channel_read_peek(QIOChannel *ioc,
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const char *buf,
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const size_t buflen,
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Error **errp)
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{
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ssize_t len = 0;
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struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen };
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while (true) {
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len = qio_channel_readv_full(ioc, &iov, 1, NULL, NULL,
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QIO_CHANNEL_READ_FLAG_MSG_PEEK, errp);
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if (len <= 0 && len != QIO_CHANNEL_ERR_BLOCK) {
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error_setg(errp,
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"Failed to peek at channel");
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return -1;
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}
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if (len == buflen) {
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break;
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}
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/* 1ms sleep. */
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if (qemu_in_coroutine()) {
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qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000);
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} else {
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g_usleep(1000);
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}
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}
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return 0;
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}
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