[PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming

Paolo Bonzini posted 37 patches 5 years, 3 months ago
Only 29 patches received!
There is a newer version of this series
[PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Paolo Bonzini 5 years, 3 months ago
Make qemu_start_incoming_migration local to migration/migration.c.
By using the runstate instead of a separate flag, vl need not do
anything to setup deferred incoming migration.

qmp_migrate_incoming also does not need the deferred_incoming flag
anymore, because "-incoming PROTOCOL" will clear the "once" flag
before the main loop starts.  Therefore, later invocations of
the migrate-incoming command will fail with the existing
"The incoming migration has already been started" error message.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/migration/misc.h |  1 -
 migration/migration.c    | 33 ++++++++-------------------------
 softmmu/vl.c             | 11 +++++++----
 3 files changed, 15 insertions(+), 30 deletions(-)

diff --git a/include/migration/misc.h b/include/migration/misc.h
index 34e7d75713..bccc1b6b44 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -58,7 +58,6 @@ void dump_vmstate_json_to_file(FILE *out_fp);
 /* migration/migration.c */
 void migration_object_init(void);
 void migration_shutdown(void);
-void qemu_start_incoming_migration(const char *uri, Error **errp);
 bool migration_is_idle(void);
 bool migration_is_active(MigrationState *);
 void add_migration_state_change_notifier(Notifier *notify);
diff --git a/migration/migration.c b/migration/migration.c
index f48b03cac2..d078094c56 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -114,8 +114,6 @@
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
 
-static bool deferred_incoming;
-
 /* Messages sent on the return path from destination to source */
 enum mig_rp_message_type {
     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
@@ -257,19 +255,6 @@ static bool migrate_late_block_activate(void)
         MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE];
 }
 
-/*
- * Called on -incoming with a defer: uri.
- * The migration can be started later after any parameters have been
- * changed.
- */
-static void deferred_incoming_migration(Error **errp)
-{
-    if (deferred_incoming) {
-        error_setg(errp, "Incoming migration already deferred");
-    }
-    deferred_incoming = true;
-}
-
 /*
  * Send a message on the return channel back to the source
  * of the migration.
@@ -380,16 +365,14 @@ void migrate_add_address(SocketAddress *address)
     addrs->value = QAPI_CLONE(SocketAddress, address);
 }
 
-void qemu_start_incoming_migration(const char *uri, Error **errp)
+static void qemu_start_incoming_migration(const char *uri, Error **errp)
 {
     const char *p = NULL;
 
     qapi_event_send_migration(MIGRATION_STATUS_SETUP);
-    if (!strcmp(uri, "defer")) {
-        deferred_incoming_migration(errp);
-    } else if (strstart(uri, "tcp:", &p) ||
-               strstart(uri, "unix:", NULL) ||
-               strstart(uri, "vsock:", NULL)) {
+    if (strstart(uri, "tcp:", &p) ||
+        strstart(uri, "unix:", NULL) ||
+        strstart(uri, "vsock:", NULL)) {
         socket_start_incoming_migration(p ? p : uri, errp);
 #ifdef CONFIG_RDMA
     } else if (strstart(uri, "rdma:", &p)) {
@@ -1926,14 +1909,14 @@ void qmp_migrate_incoming(const char *uri, Error **errp)
     Error *local_err = NULL;
     static bool once = true;
 
-    if (!deferred_incoming) {
-        error_setg(errp, "For use with '-incoming defer'");
-        return;
-    }
     if (!once) {
         error_setg(errp, "The incoming migration has already been started");
         return;
     }
+    if (!runstate_check(RUN_STATE_INMIGRATE)) {
+        error_setg(errp, "'-incoming' was not specified on the command line");
+        return;
+    }
 
     qemu_start_incoming_migration(uri, &local_err);
 
diff --git a/softmmu/vl.c b/softmmu/vl.c
index ae2854d8af..583366510b 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -109,6 +109,7 @@
 #include "qapi/qapi-visit-block-core.h"
 #include "qapi/qapi-visit-ui.h"
 #include "qapi/qapi-commands-block-core.h"
+#include "qapi/qapi-commands-migration.h"
 #include "qapi/qapi-commands-run-state.h"
 #include "qapi/qapi-commands-ui.h"
 #include "qapi/qmp/qerror.h"
@@ -4557,10 +4558,12 @@ void qemu_init(int argc, char **argv, char **envp)
     }
     if (incoming) {
         Error *local_err = NULL;
-        qemu_start_incoming_migration(incoming, &local_err);
-        if (local_err) {
-            error_reportf_err(local_err, "-incoming %s: ", incoming);
-            exit(1);
+        if (strcmp(incoming, "defer") != 0) {
+            qmp_migrate_incoming(incoming, &local_err);
+            if (local_err) {
+                error_reportf_err(local_err, "-incoming %s: ", incoming);
+                exit(1);
+            }
         }
     } else if (autostart) {
         vm_start();
-- 
2.26.2



Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Igor Mammedov 5 years, 2 months ago
On Tue, 27 Oct 2020 14:21:39 -0400
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Make qemu_start_incoming_migration local to migration/migration.c.
> By using the runstate instead of a separate flag, vl need not do
> anything to setup deferred incoming migration.
> 
> qmp_migrate_incoming also does not need the deferred_incoming flag
> anymore, because "-incoming PROTOCOL" will clear the "once" flag
> before the main loop starts.  Therefore, later invocations of
> the migrate-incoming command will fail with the existing
> "The incoming migration has already been started" error message.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  include/migration/misc.h |  1 -
>  migration/migration.c    | 33 ++++++++-------------------------
>  softmmu/vl.c             | 11 +++++++----
>  3 files changed, 15 insertions(+), 30 deletions(-)
> 
> diff --git a/include/migration/misc.h b/include/migration/misc.h
> index 34e7d75713..bccc1b6b44 100644
> --- a/include/migration/misc.h
> +++ b/include/migration/misc.h
> @@ -58,7 +58,6 @@ void dump_vmstate_json_to_file(FILE *out_fp);
>  /* migration/migration.c */
>  void migration_object_init(void);
>  void migration_shutdown(void);
> -void qemu_start_incoming_migration(const char *uri, Error **errp);
>  bool migration_is_idle(void);
>  bool migration_is_active(MigrationState *);
>  void add_migration_state_change_notifier(Notifier *notify);
> diff --git a/migration/migration.c b/migration/migration.c
> index f48b03cac2..d078094c56 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -114,8 +114,6 @@
>  static NotifierList migration_state_notifiers =
>      NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
>  
> -static bool deferred_incoming;
> -
>  /* Messages sent on the return path from destination to source */
>  enum mig_rp_message_type {
>      MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
> @@ -257,19 +255,6 @@ static bool migrate_late_block_activate(void)
>          MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE];
>  }
>  
> -/*
> - * Called on -incoming with a defer: uri.
> - * The migration can be started later after any parameters have been
> - * changed.
> - */
> -static void deferred_incoming_migration(Error **errp)
> -{
> -    if (deferred_incoming) {
> -        error_setg(errp, "Incoming migration already deferred");
> -    }
> -    deferred_incoming = true;
> -}
> -
>  /*
>   * Send a message on the return channel back to the source
>   * of the migration.
> @@ -380,16 +365,14 @@ void migrate_add_address(SocketAddress *address)
>      addrs->value = QAPI_CLONE(SocketAddress, address);
>  }
>  
> -void qemu_start_incoming_migration(const char *uri, Error **errp)
> +static void qemu_start_incoming_migration(const char *uri, Error **errp)
>  {
>      const char *p = NULL;
>  
>      qapi_event_send_migration(MIGRATION_STATUS_SETUP);
> -    if (!strcmp(uri, "defer")) {
> -        deferred_incoming_migration(errp);
> -    } else if (strstart(uri, "tcp:", &p) ||
> -               strstart(uri, "unix:", NULL) ||
> -               strstart(uri, "vsock:", NULL)) {
considering the last hunk does won't call qmp_migrate_incoming
if 'defer' was used, wouldn't we will lose QAPI event here?
not sure how important it to users,
Ccing David

> +    if (strstart(uri, "tcp:", &p) ||
> +        strstart(uri, "unix:", NULL) ||
> +        strstart(uri, "vsock:", NULL)) {
>          socket_start_incoming_migration(p ? p : uri, errp);
>  #ifdef CONFIG_RDMA
>      } else if (strstart(uri, "rdma:", &p)) {
> @@ -1926,14 +1909,14 @@ void qmp_migrate_incoming(const char *uri, Error **errp)
>      Error *local_err = NULL;
>      static bool once = true;
>  
> -    if (!deferred_incoming) {
> -        error_setg(errp, "For use with '-incoming defer'");
> -        return;
> -    }
>      if (!once) {
>          error_setg(errp, "The incoming migration has already been started");
>          return;
>      }
> +    if (!runstate_check(RUN_STATE_INMIGRATE)) {
> +        error_setg(errp, "'-incoming' was not specified on the command line");
> +        return;
> +    }
>  
>      qemu_start_incoming_migration(uri, &local_err);
>  
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index ae2854d8af..583366510b 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -109,6 +109,7 @@
>  #include "qapi/qapi-visit-block-core.h"
>  #include "qapi/qapi-visit-ui.h"
>  #include "qapi/qapi-commands-block-core.h"
> +#include "qapi/qapi-commands-migration.h"
>  #include "qapi/qapi-commands-run-state.h"
>  #include "qapi/qapi-commands-ui.h"
>  #include "qapi/qmp/qerror.h"
> @@ -4557,10 +4558,12 @@ void qemu_init(int argc, char **argv, char **envp)
>      }
>      if (incoming) {
>          Error *local_err = NULL;
> -        qemu_start_incoming_migration(incoming, &local_err);
> -        if (local_err) {
> -            error_reportf_err(local_err, "-incoming %s: ", incoming);
> -            exit(1);
> +        if (strcmp(incoming, "defer") != 0) {
> +            qmp_migrate_incoming(incoming, &local_err);
> +            if (local_err) {
> +                error_reportf_err(local_err, "-incoming %s: ", incoming);
> +                exit(1);
> +            }
>          }
>      } else if (autostart) {
>          vm_start();


Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Paolo Bonzini 5 years, 2 months ago
On 20/11/20 16:34, Igor Mammedov wrote:
>>       qapi_event_send_migration(MIGRATION_STATUS_SETUP);
>> -    if (!strcmp(uri, "defer")) {
>> -        deferred_incoming_migration(errp);
>> -    } else if (strstart(uri, "tcp:", &p) ||
>> -               strstart(uri, "unix:", NULL) ||
>> -               strstart(uri, "vsock:", NULL)) {
> considering the last hunk does won't call qmp_migrate_incoming
> if 'defer' was used, wouldn't we will lose QAPI event here?
> not sure how important it to users,

Hmm yeah that's true.  That might even be considered a bugfix (no setup 
is done until the "real" migrate-incoming command), but I can also add 
the event manually in qemu_init.

(Libvirt doesn't use the SETUP case of the event but that's of course 
only part of the story).

Paolo


Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Dr. David Alan Gilbert 5 years, 2 months ago
* Paolo Bonzini (pbonzini@redhat.com) wrote:
> On 20/11/20 16:34, Igor Mammedov wrote:
> > >       qapi_event_send_migration(MIGRATION_STATUS_SETUP);
> > > -    if (!strcmp(uri, "defer")) {
> > > -        deferred_incoming_migration(errp);
> > > -    } else if (strstart(uri, "tcp:", &p) ||
> > > -               strstart(uri, "unix:", NULL) ||
> > > -               strstart(uri, "vsock:", NULL)) {
> > considering the last hunk does won't call qmp_migrate_incoming
> > if 'defer' was used, wouldn't we will lose QAPI event here?
> > not sure how important it to users,
> 
> Hmm yeah that's true.  That might even be considered a bugfix (no setup is
> done until the "real" migrate-incoming command), but I can also add the
> event manually in qemu_init.
> 
> (Libvirt doesn't use the SETUP case of the event but that's of course only
> part of the story).

I'm more worried about how this stops a repeated 'migrate incoming'
or a 'migrate_incoming' that's issued following a qemu that's been
started with -incoming tcp:... but which a socket hasn't yet connected
to.

Dave

> Paolo
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK


Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Daniel P. Berrangé 5 years, 2 months ago
On Wed, Dec 02, 2020 at 01:10:37PM +0000, Dr. David Alan Gilbert wrote:
> * Paolo Bonzini (pbonzini@redhat.com) wrote:
> > On 20/11/20 16:34, Igor Mammedov wrote:
> > > >       qapi_event_send_migration(MIGRATION_STATUS_SETUP);
> > > > -    if (!strcmp(uri, "defer")) {
> > > > -        deferred_incoming_migration(errp);
> > > > -    } else if (strstart(uri, "tcp:", &p) ||
> > > > -               strstart(uri, "unix:", NULL) ||
> > > > -               strstart(uri, "vsock:", NULL)) {
> > > considering the last hunk does won't call qmp_migrate_incoming
> > > if 'defer' was used, wouldn't we will lose QAPI event here?
> > > not sure how important it to users,
> > 
> > Hmm yeah that's true.  That might even be considered a bugfix (no setup is
> > done until the "real" migrate-incoming command), but I can also add the
> > event manually in qemu_init.
> > 
> > (Libvirt doesn't use the SETUP case of the event but that's of course only
> > part of the story).
> 
> I'm more worried about how this stops a repeated 'migrate incoming'
> or a 'migrate_incoming' that's issued following a qemu that's been
> started with -incoming tcp:... but which a socket hasn't yet connected
> to.

Can someone remind me why we need to have an -incoming arg at all ?

With snapshots, we can just start QEMU normally, using -S if desired,
and then invoke "loadvm" to restore from a snapshot at any time.

What is different thet means we can't just run "migrate_incoming" on
any QEMU at any time, ignoring -incoming entirely ?


Regards,
Daniel
-- 
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Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Paolo Bonzini 5 years, 2 months ago
On 02/12/20 14:15, Daniel P. Berrangé wrote:
> Can someone remind me why we need to have an -incoming arg at all ?
> 
> With snapshots, we can just start QEMU normally, using -S if desired,
> and then invoke "loadvm" to restore from a snapshot at any time.
> 
> What is different thet means we can't just run "migrate_incoming" on
> any QEMU at any time, ignoring -incoming entirely ?

There are some parts of QEMU that operate differently based on 
RUN_STATE_INCOMING.  Removing those is one of the things that these 
patches should enable, though there are also some uses in Xen that I'm 
more worried about.

Paolo


Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Paolo Bonzini 5 years, 2 months ago
On 02/12/20 14:10, Dr. David Alan Gilbert wrote:
> I'm more worried about how this stops a repeated 'migrate incoming'
> or a 'migrate_incoming' that's issued following a qemu that's been
> started with -incoming tcp:... but which a socket hasn't yet connected
> to.

Good question, fortunately it is simply handled answer:

void qmp_migrate_incoming(const char *uri, Error **errp)
{
     Error *local_err = NULL;
     static bool once = true;

     if (!once) {
         error_setg(errp, "The incoming migration has already been 
started");
         return;
     }
     if (!runstate_check(RUN_STATE_INMIGRATE)) {
         error_setg(errp, "'-incoming' was not specified on the command 
line");
         return;
     }

     qemu_start_incoming_migration(uri, &local_err);

     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }

     once = false;
}

This patch can simplify things because every incoming migrations (no 
matter if '-incoming defer' or '-incoming tcp:...') goes through the 
qmp_migrate_incoming function above.

Paolo


Re: [PATCH 24/29] migration, vl: start migration via qmp_migrate_incoming
Posted by Dr. David Alan Gilbert 5 years, 2 months ago
* Paolo Bonzini (pbonzini@redhat.com) wrote:
> On 02/12/20 14:10, Dr. David Alan Gilbert wrote:
> > I'm more worried about how this stops a repeated 'migrate incoming'
> > or a 'migrate_incoming' that's issued following a qemu that's been
> > started with -incoming tcp:... but which a socket hasn't yet connected
> > to.
> 
> Good question, fortunately it is simply handled answer:
> 
> void qmp_migrate_incoming(const char *uri, Error **errp)
> {
>     Error *local_err = NULL;
>     static bool once = true;
> 
>     if (!once) {
>         error_setg(errp, "The incoming migration has already been started");
>         return;
>     }
>     if (!runstate_check(RUN_STATE_INMIGRATE)) {
>         error_setg(errp, "'-incoming' was not specified on the command
> line");
>         return;
>     }
> 
>     qemu_start_incoming_migration(uri, &local_err);
> 
>     if (local_err) {
>         error_propagate(errp, local_err);
>         return;
>     }
> 
>     once = false;
> }
> 
> This patch can simplify things because every incoming migrations (no matter
> if '-incoming defer' or '-incoming tcp:...') goes through the
> qmp_migrate_incoming function above.

Yeh I think that's OK.

Dave

> Paolo
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK