From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>,
qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v1 10/22] migration: convert tcp socket protocol to use QIOChannel
Date: Wed, 3 Feb 2016 10:33:10 +0000 [thread overview]
Message-ID: <20160203103309.GG2376@work-vm> (raw)
In-Reply-To: <20160203100217.GA30222@redhat.com>
* Daniel P. Berrange (berrange@redhat.com) wrote:
> On Tue, Feb 02, 2016 at 06:19:03PM +0000, Dr. David Alan Gilbert wrote:
> > * Daniel P. Berrange (berrange@redhat.com) wrote:
> > > Convert the tcp socket migration protocol driver to use
> > > QIOChannel and QEMUFileChannel, instead of plain sockets
> > > APIs.
> > >
> > > While this now looks pretty similar to the migration/unix.c
> > > file from the previous patch, it was decided not to merge
> > > the two, because when TLS is added to the TCP impl later,
> > > this file diverge from unix.c once again.
> >
> > Hmm OK, although I'd kind of like to see merging, but lets
> > see the TLS code later in the series....
> >
> > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> > > ---
> > > migration/tcp.c | 119 ++++++++++++++++++++++++++++++++++++++------------------
> > > 1 file changed, 82 insertions(+), 37 deletions(-)
> > >
> > > diff --git a/migration/tcp.c b/migration/tcp.c
> > > index ae89172..ac73977 100644
> > > --- a/migration/tcp.c
> > > +++ b/migration/tcp.c
> > > @@ -2,9 +2,11 @@
> > > * QEMU live migration
> > > *
> > > * Copyright IBM, Corp. 2008
> > > + * Copyright Red Hat, Inc. 2015
> > > *
> > > * Authors:
> > > * Anthony Liguori <aliguori@us.ibm.com>
> > > + * Daniel P. Berrange <berrange@redhat.com>
> > > *
> > > * This work is licensed under the terms of the GNU GPL, version 2. See
> > > * the COPYING file in the top-level directory.
> > > @@ -17,11 +19,9 @@
> > >
> > > #include "qemu-common.h"
> > > #include "qemu/error-report.h"
> > > -#include "qemu/sockets.h"
> > > #include "migration/migration.h"
> > > #include "migration/qemu-file.h"
> > > -#include "block/block.h"
> > > -#include "qemu/main-loop.h"
> > > +#include "io/channel-socket.h"
> > >
> > > //#define DEBUG_MIGRATION_TCP
> > >
> > > @@ -33,71 +33,116 @@
> > > do { } while (0)
> > > #endif
> > >
> > > -static void tcp_wait_for_connect(int fd, Error *err, void *opaque)
> > > +
> > > +static SocketAddress *tcp_build_address(const char *host_port, Error **errp)
> > > +{
> > > + InetSocketAddress *iaddr = inet_parse(host_port, errp);
> > > + SocketAddress *saddr;
> > > +
> > > + if (!iaddr) {
> > > + return NULL;
> > > + }
> > > +
> > > + saddr = g_new0(SocketAddress, 1);
> > > + saddr->type = SOCKET_ADDRESS_KIND_INET;
> > > + saddr->u.inet = iaddr;
> > > +
> > > + return saddr;
> > > +}
> > > +
> > > +
> > > +static void tcp_outgoing_migration(Object *src,
> > > + Error *err,
> > > + gpointer opaque)
> > > {
> > > MigrationState *s = opaque;
> > > + QIOChannel *sioc = QIO_CHANNEL(src);
> > >
> > > - if (fd < 0) {
> > > + if (err) {
> > > DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
> > > s->file = NULL;
> > > migrate_fd_error(s);
> > > } else {
> > > DPRINTF("migrate connect success\n");
> > > - s->file = qemu_fopen_socket(fd, "wb");
> > > + s->file = qemu_fopen_channel_output(sioc);
> > > migrate_fd_connect(s);
> > > }
> > > + object_unref(src);
> > > }
> > >
> > > -void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp)
> > > +
> > > +void tcp_start_outgoing_migration(MigrationState *s,
> > > + const char *host_port,
> > > + Error **errp)
> > > {
> > > - inet_nonblocking_connect(host_port, tcp_wait_for_connect, s, errp);
> > > + SocketAddress *saddr = tcp_build_address(host_port, errp);
> > > + QIOChannelSocket *sioc;
> > > +
> > > + if (!saddr) {
> > > + return;
> > > + }
> > > +
> > > + sioc = qio_channel_socket_new();
> > > + qio_channel_socket_connect_async(sioc,
> > > + saddr,
> > > + tcp_outgoing_migration,
> > > + s,
> > > + NULL);
> > > + qapi_free_SocketAddress(saddr);
> > > }
> > >
> > > -static void tcp_accept_incoming_migration(void *opaque)
> > > +
> > > +static gboolean tcp_accept_incoming_migration(QIOChannel *ioc,
> > > + GIOCondition condition,
> > > + gpointer opaque)
> > > {
> > > - struct sockaddr_in addr;
> > > - socklen_t addrlen = sizeof(addr);
> > > - int s = (intptr_t)opaque;
> > > QEMUFile *f;
> > > - int c, err;
> > > + QIOChannelSocket *cioc;
> > > + Error *err = NULL;
> > >
> > > - do {
> > > - c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
> > > - err = socket_error();
> > > - } while (c < 0 && err == EINTR);
> > > - qemu_set_fd_handler(s, NULL, NULL, NULL);
> > > - closesocket(s);
> > > -
> > > - DPRINTF("accepted migration\n");
> > > -
> > > - if (c < 0) {
> > > + cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
> > > + &err);
> > > + if (!cioc) {
> > > error_report("could not accept migration connection (%s)",
> > > - strerror(err));
> > > - return;
> > > - }
> > > -
> > > - f = qemu_fopen_socket(c, "rb");
> > > - if (f == NULL) {
> > > - error_report("could not qemu_fopen socket");
> > > + error_get_pretty(err));
> > > goto out;
> > > }
> > >
> > > + DPRINTF("accepted migration\n");
> > > +
> > > + f = qemu_fopen_channel_input(QIO_CHANNEL(cioc));
> > > + object_unref(OBJECT(cioc));
> > > +
> > > process_incoming_migration(f);
> > > - return;
> > >
> > > out:
> > > - closesocket(c);
> > > + /* Close listening socket as its no longer needed */
> > > + qio_channel_close(ioc, NULL);
> > > + return FALSE;
> > > }
> > >
> > > +
> > > void tcp_start_incoming_migration(const char *host_port, Error **errp)
> > > {
> > > - int s;
> > > + SocketAddress *saddr = tcp_build_address(host_port, errp);
> > > + QIOChannelSocket *listen_ioc;
> > >
> > > - s = inet_listen(host_port, NULL, 256, SOCK_STREAM, 0, errp);
> > > - if (s < 0) {
> > > + if (!saddr) {
> > > return;
> > > }
> > >
> > > - qemu_set_fd_handler(s, tcp_accept_incoming_migration, NULL,
> > > - (void *)(intptr_t)s);
> > > + listen_ioc = qio_channel_socket_new();
> > > + if (qio_channel_socket_listen_sync(listen_ioc, saddr, errp) < 0) {
> >
> > In this case, although weird, that could block couldn't it?
> > The case I'm thinking of is using the migrate_incoming command with a hostname
> > (I've used it with hostnames before as aliases for networks to listen on,
> > admittedly it be rare for it to be DNS that would block).
>
> Yes it certainly could block and this is undesirable in general. The problem
> is that the only way we can provide errors back for the monitor reponse is
> if we do this synchronously from this method. If I ran async then we'd have
> no ability to report errors about non-existant host names, already in use tcp
> port, etc.
>
> I'm not really sure what todo about this long term, but the only way would
> be if the monitor response was able to be sent back asychronously from
> this method call. Then we can start an async listen call, and respond to
> the monitor when done.
>
> Since the current code being replaced is also blocking, I felt solving
> that problem is best left to a future patch series. At least with this
> explicit method naming with _sync() suffix we can easily identify the
> problems in future
Yeh that's fair enough. Failed incoming migrations generally just quit anyway.
Dave
>
> Regards,
> Daniel
> --
> |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
> |: http://libvirt.org -o- http://virt-manager.org :|
> |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
> |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2016-02-03 10:33 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-12 11:43 [Qemu-devel] [PATCH v1 00/22] Convert migration to QIOChannel & support TLS Daniel P. Berrange
2016-01-12 11:43 ` [Qemu-devel] [PATCH v1 01/22] s390: use FILE instead of QEMUFile for creating text file Daniel P. Berrange
2016-01-12 11:58 ` Cornelia Huck
2016-01-12 12:01 ` Daniel P. Berrange
2016-01-12 12:05 ` Cornelia Huck
2016-02-12 17:19 ` Dr. David Alan Gilbert
2016-01-12 11:43 ` [Qemu-devel] [PATCH v1 02/22] migration: remove use of qemu_bufopen from vmstate tests Daniel P. Berrange
2016-01-28 17:45 ` Dr. David Alan Gilbert
2016-01-12 11:43 ` [Qemu-devel] [PATCH v1 03/22] migration: ensure qemu_fflush() always writes full data amount Daniel P. Berrange
2016-01-28 17:53 ` Dr. David Alan Gilbert
2016-02-03 13:31 ` Daniel P. Berrange
2016-01-12 11:43 ` [Qemu-devel] [PATCH v1 04/22] migration: split migration hooks out of QEMUFileOps Daniel P. Berrange
2016-01-28 17:57 ` Dr. David Alan Gilbert
2016-01-12 11:43 ` [Qemu-devel] [PATCH v1 05/22] migration: introduce set_blocking function in QEMUFileOps Daniel P. Berrange
2016-01-28 18:00 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 06/22] migration: force QEMUFile to blocking mode for outgoing migration Daniel P. Berrange
2016-01-28 18:17 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 07/22] migration: introduce a new QEMUFile impl based on QIOChannel Daniel P. Berrange
2016-02-02 17:06 ` Dr. David Alan Gilbert
2016-02-03 13:37 ` Daniel P. Berrange
2016-02-12 17:16 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 08/22] migration: convert post-copy to use QIOChannelBuffer Daniel P. Berrange
2016-01-25 19:38 ` Dr. David Alan Gilbert
2016-01-25 22:15 ` Daniel P. Berrange
2016-01-26 18:59 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 09/22] migration: convert unix socket protocol to use QIOChannel Daniel P. Berrange
2016-02-02 18:02 ` Dr. David Alan Gilbert
2016-02-03 11:25 ` Daniel P. Berrange
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 10/22] migration: convert tcp " Daniel P. Berrange
2016-02-02 18:19 ` Dr. David Alan Gilbert
2016-02-03 10:02 ` Daniel P. Berrange
2016-02-03 10:33 ` Dr. David Alan Gilbert [this message]
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 11/22] migration: convert fd " Daniel P. Berrange
2016-02-02 18:46 ` Dr. David Alan Gilbert
2016-02-03 10:05 ` Daniel P. Berrange
2016-02-03 10:29 ` Dr. David Alan Gilbert
2016-02-03 10:39 ` Daniel P. Berrange
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 12/22] migration: convert exec " Daniel P. Berrange
2016-02-02 18:53 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 13/22] migration: convert RDMA to use QIOChannel interface Daniel P. Berrange
2016-02-02 20:01 ` Dr. David Alan Gilbert
2016-02-03 11:37 ` Daniel P. Berrange
2016-02-03 13:23 ` Dr. David Alan Gilbert
2016-02-03 13:25 ` Daniel P. Berrange
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 14/22] migration: convert savevm to use QIOChannel for writing to files Daniel P. Berrange
2016-02-03 9:52 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 15/22] migration: delete QEMUFile buffer implementation Daniel P. Berrange
2016-02-03 9:54 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 16/22] migration: delete QEMUSizedBuffer struct Daniel P. Berrange
2016-02-03 9:55 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 17/22] migration: delete QEMUFile sockets implementation Daniel P. Berrange
2016-02-03 9:56 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 18/22] migration: delete QEMUFile stdio implementation Daniel P. Berrange
2016-02-03 9:58 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 19/22] migration: move definition of struct QEMUFile back into qemu-file.c Daniel P. Berrange
2016-02-05 18:32 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 20/22] migration: support TLS encryption with TCP migration backend Daniel P. Berrange
2016-02-12 17:09 ` Dr. David Alan Gilbert
2016-02-12 17:25 ` Daniel P. Berrange
2016-02-15 11:00 ` Daniel P. Berrange
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 21/22] migration: remove support for non-iovec based write handlers Daniel P. Berrange
2016-02-12 15:48 ` Dr. David Alan Gilbert
2016-01-12 11:44 ` [Qemu-devel] [PATCH v1 22/22] migration: remove qemu_get_fd method from QEMUFile Daniel P. Berrange
2016-02-12 15:51 ` Dr. David Alan Gilbert
2016-01-12 11:59 ` [Qemu-devel] [PATCH v1 00/22] Convert migration to QIOChannel & support TLS Daniel P. Berrange
2016-01-20 18:01 ` Daniel P. Berrange
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