[Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram

Greg Kurz posted 1 patch 6 years, 1 month ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/151801810352.29167.4832480228518630626.stgit@bahia.lan
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docs/devel/migration.rst |    4 ++--
hmp-commands.hx          |    3 ++-
qapi/migration.json      |   10 ++++++----
3 files changed, 10 insertions(+), 7 deletions(-)
[Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram
Posted by Greg Kurz 6 years, 1 month ago
This capability must have the same value on both source and destination,
otherwise migration fails (commit 875fcd013ab6 "migration: incoming
postcopy advise sanity checks").

Let's write it down in various places where postcopy-ram is documented.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 docs/devel/migration.rst |    4 ++--
 hmp-commands.hx          |    3 ++-
 qapi/migration.json      |   10 ++++++----
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
index bf97080dac2f..9d1b7657f0cf 100644
--- a/docs/devel/migration.rst
+++ b/docs/devel/migration.rst
@@ -387,8 +387,8 @@ doesn't finish in a given time the switch is made to postcopy.
 Enabling postcopy
 -----------------
 
-To enable postcopy, issue this command on the monitor prior to the
-start of migration:
+To enable postcopy, issue this command on the monitor (both source and
+destination) prior to the start of migration:
 
 ``migrate_set_capability postcopy-ram on``
 
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 15620c94d3fc..d26eb4119b9d 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1041,7 +1041,8 @@ ETEXI
         .params     = "",
         .help       = "Followup to a migration command to switch the migration"
                       " to postcopy mode. The postcopy-ram capability must "
-                      "be set before the original migration command.",
+                      "be set on both source and destination before the "
+                      "original migration command .",
         .cmd        = hmp_migrate_start_postcopy,
     },
 
diff --git a/qapi/migration.json b/qapi/migration.json
index 4cd3d1315884..7f465a1902ce 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -327,8 +327,10 @@
 #          to speed up convergence of RAM migration. (since 1.6)
 #
 # @postcopy-ram: Start executing on the migration target before all of RAM has
-#          been migrated, pulling the remaining pages along as needed. NOTE: If
-#          the migration fails during postcopy the VM will fail.  (since 2.6)
+#          been migrated, pulling the remaining pages along as needed. The
+#          capacity must have the same setting on both source and target
+#          or migration will not even start. NOTE: If the migration fails during
+#          postcopy the VM will fail.  (since 2.6)
 #
 # @x-colo: If enabled, migration will never end, and the state of the VM on the
 #        primary side will be migrated continuously to the VM on secondary
@@ -742,8 +744,8 @@
 # @migrate-start-postcopy:
 #
 # Followup to a migration command to switch the migration to postcopy mode.
-# The postcopy-ram capability must be set before the original migration
-# command.
+# The postcopy-ram capability must be set on both source and destination
+# before the original migration command.
 #
 # Since: 2.5
 #


Re: [Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram
Posted by Eric Blake 6 years, 1 month ago
On 02/07/2018 09:41 AM, Greg Kurz wrote:
> This capability must have the same value on both source and destination,
> otherwise migration fails (commit 875fcd013ab6 "migration: incoming
> postcopy advise sanity checks").
> 
> Let's write it down in various places where postcopy-ram is documented.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>
> ---
>   docs/devel/migration.rst |    4 ++--
>   hmp-commands.hx          |    3 ++-
>   qapi/migration.json      |   10 ++++++----
>   3 files changed, 10 insertions(+), 7 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram
Posted by Dr. David Alan Gilbert 6 years, 1 month ago
* Greg Kurz (groug@kaod.org) wrote:
> This capability must have the same value on both source and destination,
> otherwise migration fails (commit 875fcd013ab6 "migration: incoming
> postcopy advise sanity checks").
> 
> Let's write it down in various places where postcopy-ram is documented.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>

Thanks,

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  docs/devel/migration.rst |    4 ++--
>  hmp-commands.hx          |    3 ++-
>  qapi/migration.json      |   10 ++++++----
>  3 files changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
> index bf97080dac2f..9d1b7657f0cf 100644
> --- a/docs/devel/migration.rst
> +++ b/docs/devel/migration.rst
> @@ -387,8 +387,8 @@ doesn't finish in a given time the switch is made to postcopy.
>  Enabling postcopy
>  -----------------
>  
> -To enable postcopy, issue this command on the monitor prior to the
> -start of migration:
> +To enable postcopy, issue this command on the monitor (both source and
> +destination) prior to the start of migration:
>  
>  ``migrate_set_capability postcopy-ram on``
>  
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 15620c94d3fc..d26eb4119b9d 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1041,7 +1041,8 @@ ETEXI
>          .params     = "",
>          .help       = "Followup to a migration command to switch the migration"
>                        " to postcopy mode. The postcopy-ram capability must "
> -                      "be set before the original migration command.",
> +                      "be set on both source and destination before the "
> +                      "original migration command .",
>          .cmd        = hmp_migrate_start_postcopy,
>      },
>  
> diff --git a/qapi/migration.json b/qapi/migration.json
> index 4cd3d1315884..7f465a1902ce 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -327,8 +327,10 @@
>  #          to speed up convergence of RAM migration. (since 1.6)
>  #
>  # @postcopy-ram: Start executing on the migration target before all of RAM has
> -#          been migrated, pulling the remaining pages along as needed. NOTE: If
> -#          the migration fails during postcopy the VM will fail.  (since 2.6)
> +#          been migrated, pulling the remaining pages along as needed. The
> +#          capacity must have the same setting on both source and target
> +#          or migration will not even start. NOTE: If the migration fails during
> +#          postcopy the VM will fail.  (since 2.6)
>  #
>  # @x-colo: If enabled, migration will never end, and the state of the VM on the
>  #        primary side will be migrated continuously to the VM on secondary
> @@ -742,8 +744,8 @@
>  # @migrate-start-postcopy:
>  #
>  # Followup to a migration command to switch the migration to postcopy mode.
> -# The postcopy-ram capability must be set before the original migration
> -# command.
> +# The postcopy-ram capability must be set on both source and destination
> +# before the original migration command.
>  #
>  # Since: 2.5
>  #
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram
Posted by Greg Kurz 6 years, 1 month ago
On Wed, 7 Feb 2018 15:55:01 +0000
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:

> * Greg Kurz (groug@kaod.org) wrote:
> > This capability must have the same value on both source and destination,
> > otherwise migration fails (commit 875fcd013ab6 "migration: incoming
> > postcopy advise sanity checks").
> > 
> > Let's write it down in various places where postcopy-ram is documented.
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>  
> 
> Thanks,
> 
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 

Who should pick this up ?

> > ---
> >  docs/devel/migration.rst |    4 ++--
> >  hmp-commands.hx          |    3 ++-
> >  qapi/migration.json      |   10 ++++++----
> >  3 files changed, 10 insertions(+), 7 deletions(-)
> > 
> > diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
> > index bf97080dac2f..9d1b7657f0cf 100644
> > --- a/docs/devel/migration.rst
> > +++ b/docs/devel/migration.rst
> > @@ -387,8 +387,8 @@ doesn't finish in a given time the switch is made to postcopy.
> >  Enabling postcopy
> >  -----------------
> >  
> > -To enable postcopy, issue this command on the monitor prior to the
> > -start of migration:
> > +To enable postcopy, issue this command on the monitor (both source and
> > +destination) prior to the start of migration:
> >  
> >  ``migrate_set_capability postcopy-ram on``
> >  
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index 15620c94d3fc..d26eb4119b9d 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -1041,7 +1041,8 @@ ETEXI
> >          .params     = "",
> >          .help       = "Followup to a migration command to switch the migration"
> >                        " to postcopy mode. The postcopy-ram capability must "
> > -                      "be set before the original migration command.",
> > +                      "be set on both source and destination before the "
> > +                      "original migration command .",
> >          .cmd        = hmp_migrate_start_postcopy,
> >      },
> >  
> > diff --git a/qapi/migration.json b/qapi/migration.json
> > index 4cd3d1315884..7f465a1902ce 100644
> > --- a/qapi/migration.json
> > +++ b/qapi/migration.json
> > @@ -327,8 +327,10 @@
> >  #          to speed up convergence of RAM migration. (since 1.6)
> >  #
> >  # @postcopy-ram: Start executing on the migration target before all of RAM has
> > -#          been migrated, pulling the remaining pages along as needed. NOTE: If
> > -#          the migration fails during postcopy the VM will fail.  (since 2.6)
> > +#          been migrated, pulling the remaining pages along as needed. The
> > +#          capacity must have the same setting on both source and target
> > +#          or migration will not even start. NOTE: If the migration fails during
> > +#          postcopy the VM will fail.  (since 2.6)
> >  #
> >  # @x-colo: If enabled, migration will never end, and the state of the VM on the
> >  #        primary side will be migrated continuously to the VM on secondary
> > @@ -742,8 +744,8 @@
> >  # @migrate-start-postcopy:
> >  #
> >  # Followup to a migration command to switch the migration to postcopy mode.
> > -# The postcopy-ram capability must be set before the original migration
> > -# command.
> > +# The postcopy-ram capability must be set on both source and destination
> > +# before the original migration command.
> >  #
> >  # Since: 2.5
> >  #
> >   
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> 


Re: [Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram
Posted by Dr. David Alan Gilbert 6 years, 1 month ago
* Greg Kurz (groug@kaod.org) wrote:
> On Wed, 7 Feb 2018 15:55:01 +0000
> "Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> 
> > * Greg Kurz (groug@kaod.org) wrote:
> > > This capability must have the same value on both source and destination,
> > > otherwise migration fails (commit 875fcd013ab6 "migration: incoming
> > > postcopy advise sanity checks").
> > > 
> > > Let's write it down in various places where postcopy-ram is documented.
> > > 
> > > Signed-off-by: Greg Kurz <groug@kaod.org>  
> > 
> > Thanks,
> > 
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > 
> 
> Who should pick this up ?

I was going to pick it up in a migration pull today.

Dave

> > > ---
> > >  docs/devel/migration.rst |    4 ++--
> > >  hmp-commands.hx          |    3 ++-
> > >  qapi/migration.json      |   10 ++++++----
> > >  3 files changed, 10 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
> > > index bf97080dac2f..9d1b7657f0cf 100644
> > > --- a/docs/devel/migration.rst
> > > +++ b/docs/devel/migration.rst
> > > @@ -387,8 +387,8 @@ doesn't finish in a given time the switch is made to postcopy.
> > >  Enabling postcopy
> > >  -----------------
> > >  
> > > -To enable postcopy, issue this command on the monitor prior to the
> > > -start of migration:
> > > +To enable postcopy, issue this command on the monitor (both source and
> > > +destination) prior to the start of migration:
> > >  
> > >  ``migrate_set_capability postcopy-ram on``
> > >  
> > > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > > index 15620c94d3fc..d26eb4119b9d 100644
> > > --- a/hmp-commands.hx
> > > +++ b/hmp-commands.hx
> > > @@ -1041,7 +1041,8 @@ ETEXI
> > >          .params     = "",
> > >          .help       = "Followup to a migration command to switch the migration"
> > >                        " to postcopy mode. The postcopy-ram capability must "
> > > -                      "be set before the original migration command.",
> > > +                      "be set on both source and destination before the "
> > > +                      "original migration command .",
> > >          .cmd        = hmp_migrate_start_postcopy,
> > >      },
> > >  
> > > diff --git a/qapi/migration.json b/qapi/migration.json
> > > index 4cd3d1315884..7f465a1902ce 100644
> > > --- a/qapi/migration.json
> > > +++ b/qapi/migration.json
> > > @@ -327,8 +327,10 @@
> > >  #          to speed up convergence of RAM migration. (since 1.6)
> > >  #
> > >  # @postcopy-ram: Start executing on the migration target before all of RAM has
> > > -#          been migrated, pulling the remaining pages along as needed. NOTE: If
> > > -#          the migration fails during postcopy the VM will fail.  (since 2.6)
> > > +#          been migrated, pulling the remaining pages along as needed. The
> > > +#          capacity must have the same setting on both source and target
> > > +#          or migration will not even start. NOTE: If the migration fails during
> > > +#          postcopy the VM will fail.  (since 2.6)
> > >  #
> > >  # @x-colo: If enabled, migration will never end, and the state of the VM on the
> > >  #        primary side will be migrated continuously to the VM on secondary
> > > @@ -742,8 +744,8 @@
> > >  # @migrate-start-postcopy:
> > >  #
> > >  # Followup to a migration command to switch the migration to postcopy mode.
> > > -# The postcopy-ram capability must be set before the original migration
> > > -# command.
> > > +# The postcopy-ram capability must be set on both source and destination
> > > +# before the original migration command.
> > >  #
> > >  # Since: 2.5
> > >  #
> > >   
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH] migration: improve documentation of postcopy-ram
Posted by Greg Kurz 6 years, 1 month ago
On Wed, 14 Feb 2018 09:45:50 +0000
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:

> * Greg Kurz (groug@kaod.org) wrote:
> > On Wed, 7 Feb 2018 15:55:01 +0000
> > "Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> >   
> > > * Greg Kurz (groug@kaod.org) wrote:  
> > > > This capability must have the same value on both source and destination,
> > > > otherwise migration fails (commit 875fcd013ab6 "migration: incoming
> > > > postcopy advise sanity checks").
> > > > 
> > > > Let's write it down in various places where postcopy-ram is documented.
> > > > 
> > > > Signed-off-by: Greg Kurz <groug@kaod.org>    
> > > 
> > > Thanks,
> > > 
> > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > >   
> > 
> > Who should pick this up ?  
> 
> I was going to pick it up in a migration pull today.
> 

Cool, thanks !

> Dave
> 
> > > > ---
> > > >  docs/devel/migration.rst |    4 ++--
> > > >  hmp-commands.hx          |    3 ++-
> > > >  qapi/migration.json      |   10 ++++++----
> > > >  3 files changed, 10 insertions(+), 7 deletions(-)
> > > > 
> > > > diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
> > > > index bf97080dac2f..9d1b7657f0cf 100644
> > > > --- a/docs/devel/migration.rst
> > > > +++ b/docs/devel/migration.rst
> > > > @@ -387,8 +387,8 @@ doesn't finish in a given time the switch is made to postcopy.
> > > >  Enabling postcopy
> > > >  -----------------
> > > >  
> > > > -To enable postcopy, issue this command on the monitor prior to the
> > > > -start of migration:
> > > > +To enable postcopy, issue this command on the monitor (both source and
> > > > +destination) prior to the start of migration:
> > > >  
> > > >  ``migrate_set_capability postcopy-ram on``
> > > >  
> > > > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > > > index 15620c94d3fc..d26eb4119b9d 100644
> > > > --- a/hmp-commands.hx
> > > > +++ b/hmp-commands.hx
> > > > @@ -1041,7 +1041,8 @@ ETEXI
> > > >          .params     = "",
> > > >          .help       = "Followup to a migration command to switch the migration"
> > > >                        " to postcopy mode. The postcopy-ram capability must "
> > > > -                      "be set before the original migration command.",
> > > > +                      "be set on both source and destination before the "
> > > > +                      "original migration command .",
> > > >          .cmd        = hmp_migrate_start_postcopy,
> > > >      },
> > > >  
> > > > diff --git a/qapi/migration.json b/qapi/migration.json
> > > > index 4cd3d1315884..7f465a1902ce 100644
> > > > --- a/qapi/migration.json
> > > > +++ b/qapi/migration.json
> > > > @@ -327,8 +327,10 @@
> > > >  #          to speed up convergence of RAM migration. (since 1.6)
> > > >  #
> > > >  # @postcopy-ram: Start executing on the migration target before all of RAM has
> > > > -#          been migrated, pulling the remaining pages along as needed. NOTE: If
> > > > -#          the migration fails during postcopy the VM will fail.  (since 2.6)
> > > > +#          been migrated, pulling the remaining pages along as needed. The
> > > > +#          capacity must have the same setting on both source and target
> > > > +#          or migration will not even start. NOTE: If the migration fails during
> > > > +#          postcopy the VM will fail.  (since 2.6)
> > > >  #
> > > >  # @x-colo: If enabled, migration will never end, and the state of the VM on the
> > > >  #        primary side will be migrated continuously to the VM on secondary
> > > > @@ -742,8 +744,8 @@
> > > >  # @migrate-start-postcopy:
> > > >  #
> > > >  # Followup to a migration command to switch the migration to postcopy mode.
> > > > -# The postcopy-ram capability must be set before the original migration
> > > > -# command.
> > > > +# The postcopy-ram capability must be set on both source and destination
> > > > +# before the original migration command.
> > > >  #
> > > >  # Since: 2.5
> > > >  #
> > > >     
> > > --
> > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > >   
> >   
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK