131fe9b843
libvirt prefers opening the TCP connection itself, for two reasons. First, connection failed errors can be detected easier, without having to parse qemu's error output. Second, libvirt might be asked to secure the transfer by tunnelling the communication through an TLS layer. Therefore, libvirt opens the TCP connection itself and passes an FD to qemu using QMP and a POSIX-specific mechanism. Hence, in order to make the reverse-path work in such cases, qemu needs to distinguish if the transmitted FD is a socket (reverse-path available) or not (reverse-path might not be available) and use the corresponding abstraction. Signed-off-by: Cristian Klein <cristian.klein@cs.umu.se> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com>
89 lines
2.0 KiB
C
89 lines
2.0 KiB
C
/*
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* QEMU live migration via generic fd
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*
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* Copyright Red Hat, Inc. 2009
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*
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* Authors:
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* Chris Lalancette <clalance@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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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-common.h"
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#include "qemu/main-loop.h"
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#include "qemu/sockets.h"
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#include "migration/migration.h"
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#include "monitor/monitor.h"
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#include "migration/qemu-file.h"
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#include "block/block.h"
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//#define DEBUG_MIGRATION_FD
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#ifdef DEBUG_MIGRATION_FD
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#define DPRINTF(fmt, ...) \
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do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
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#else
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#define DPRINTF(fmt, ...) \
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do { } while (0)
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#endif
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static bool fd_is_socket(int fd)
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{
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struct stat stat;
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int ret = fstat(fd, &stat);
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if (ret == -1) {
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/* When in doubt say no */
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return false;
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}
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return S_ISSOCK(stat.st_mode);
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}
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void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
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{
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int fd = monitor_get_fd(cur_mon, fdname, errp);
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if (fd == -1) {
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return;
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}
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if (fd_is_socket(fd)) {
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s->file = qemu_fopen_socket(fd, "wb");
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} else {
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s->file = qemu_fdopen(fd, "wb");
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}
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migrate_fd_connect(s);
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}
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static void fd_accept_incoming_migration(void *opaque)
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{
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QEMUFile *f = opaque;
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qemu_set_fd_handler2(qemu_get_fd(f), NULL, NULL, NULL, NULL);
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process_incoming_migration(f);
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}
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void fd_start_incoming_migration(const char *infd, Error **errp)
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{
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int fd;
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QEMUFile *f;
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DPRINTF("Attempting to start an incoming migration via fd\n");
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fd = strtol(infd, NULL, 0);
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if (fd_is_socket(fd)) {
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f = qemu_fopen_socket(fd, "rb");
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} else {
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f = qemu_fdopen(fd, "rb");
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}
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if(f == NULL) {
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error_setg_errno(errp, errno, "failed to open the source descriptor");
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return;
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}
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qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f);
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}
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