On Mon, Jul 17, 2017 at 03:42:23PM +0200, Juan Quintela wrote:
> We need to receive the ioc to be able to implement multifd.
>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
> migration/channel.c | 3 +--
> migration/migration.c | 16 +++++++++++++---
> migration/migration.h | 2 ++
> 3 files changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/migration/channel.c b/migration/channel.c
> index 719055d..5b777ef 100644
> --- a/migration/channel.c
> +++ b/migration/channel.c
> @@ -36,8 +36,7 @@ gboolean migration_channel_process_incoming(QIOChannel *ioc)
> error_report_err(local_err);
> }
> } else {
> - QEMUFile *f = qemu_fopen_channel_input(ioc);
> - migration_fd_process_incoming(f);
> + return migration_ioc_process_incoming(ioc);
> }
> return FALSE; /* unregister */
> }
This is going to break TLS with multi FD I'm afraid.
We have two code paths:
1. Non-TLS
event loop POLLIN on migration listener socket
+-> socket_accept_incoming_migration()
+-> migration_channel_process_incoming()
+-> migration_ioc_process_incoming()
-> returns FALSE if all required FD channels are now present
2. TLS
event loop POLLIN on migration listener socket
+-> socket_accept_incoming_migration()
+-> migration_channel_process_incoming()
+-> migration_tls_channel_process_incoming
-> Registers watch for TLS handhsake on client socket
-> returns FALSE immediately to remove listener watch
event loop POLLIN on migration *client* socket
+-> migration_tls_incoming_handshake
+-> migration_channel_process_incoming()
+-> migration_ioc_process_incoming()
-> return value ignored
So, in this patch your going to immediately unregister the
migration listener socket watch when the TLS handshake
starts.
You can't rely on propagating a return value back from
migration_ioc_process_incoming(), because that is called
from a different context when using TLS.
To fix this we need to migrati onsocket_accept_incoming_migration()
so that it can do a call like
if (migration_expect_more_clients())
return TRUE;
else
return FALSE;
and have migration_expect_more_clients() do something like
if (migrate_use_multifd() && mulitfd_recv_state->count < thread_count)
return TRUE;
else
return FALSE;
> diff --git a/migration/migration.c b/migration/migration.c
> index a0db40d..c24ad03 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -299,17 +299,15 @@ static void process_incoming_migration_bh(void *opaque)
>
> static void process_incoming_migration_co(void *opaque)
> {
> - QEMUFile *f = opaque;
> MigrationIncomingState *mis = migration_incoming_get_current();
> PostcopyState ps;
> int ret;
>
> - mis->from_src_file = f;
> mis->largest_page_size = qemu_ram_pagesize_largest();
> postcopy_state_set(POSTCOPY_INCOMING_NONE);
> migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
> MIGRATION_STATUS_ACTIVE);
> - ret = qemu_loadvm_state(f);
> + ret = qemu_loadvm_state(mis->from_src_file);
>
> ps = postcopy_state_get();
> trace_process_incoming_migration_co_end(ret, ps);
> @@ -362,6 +360,18 @@ void migration_fd_process_incoming(QEMUFile *f)
> qemu_coroutine_enter(co);
> }
>
> +gboolean migration_ioc_process_incoming(QIOChannel *ioc)
> +{
> + MigrationIncomingState *mis = migration_incoming_get_current();
> +
> + if (!mis->from_src_file) {
> + QEMUFile *f = qemu_fopen_channel_input(ioc);
> + mis->from_src_file = f;
> + migration_fd_process_incoming(f);
> + }
> + return FALSE; /* unregister */
> +}
> +
> /*
> * Send a 'SHUT' message on the return channel with the given value
> * to indicate that we've finished with the RP. Non-0 value indicates
> diff --git a/migration/migration.h b/migration/migration.h
> index 148c9fa..5a18aea 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -20,6 +20,7 @@
> #include "exec/cpu-common.h"
> #include "qemu/coroutine_int.h"
> #include "hw/qdev.h"
> +#include "io/channel.h"
>
> /* State for the incoming migration */
> struct MigrationIncomingState {
> @@ -152,6 +153,7 @@ struct MigrationState
> void migrate_set_state(int *state, int old_state, int new_state);
>
> void migration_fd_process_incoming(QEMUFile *f);
> +gboolean migration_ioc_process_incoming(QIOChannel *ioc);
>
> uint64_t migrate_max_downtime(void);
>
> --
> 2.9.4
>
Regards,
Daniel
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