Hi Igor
On Mon, 8 Apr 2019 at 18:35, Igor Mammedov <imamm...@redhat.com> wrote:
> On Sun, 7 Apr 2019 22:19:05 -0400
> Catherine Ho <catherine.h...@gmail.com> wrote:
>
> > Currently it is not forbidden to use "-object
> memory-backend-file,share=on"
> > and together with "-incoming". But after incoming migration is finished,
> > the memory-backend-file will be definitely written if share=on. So the
> > memory-backend-file can only be used once, but failed in the 2nd time
> > incoming.
> >
> > Thus it gives a warning and the users can run the qemu if they really
> > want to do it.
>
> Shouldn't we add a migration blocker in such a case instead of warning
> and letting qemu run wild?
>
IMO, it doesn't need to block this. With share=on and -incoming, the user
can
still save the device memory state into memory-backend file again if
ignore-shared
capability is on.
If we block this, the user can't use the ignore-shared capability in
incoming
migration.
B.R.
Catherine
>
>
> > Signed-off-by: Catherine Ho <catherine.h...@gmail.com>
> > ---
> > backends/hostmem-file.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
> > index 37ac6445d2..59429ee0b4 100644
> > --- a/backends/hostmem-file.c
> > +++ b/backends/hostmem-file.c
> > @@ -16,6 +16,7 @@
> > #include "sysemu/hostmem.h"
> > #include "sysemu/sysemu.h"
> > #include "qom/object_interfaces.h"
> > +#include "migration/migration.h"
> >
> > /* hostmem-file.c */
> > /**
> > @@ -79,6 +80,16 @@ file_backend_memory_alloc(HostMemoryBackend *backend,
> Error **errp)
> > }
> > }
> >
> > + /*
> > + * In ignore shared case, if share=on for host memory backend file,
> > + * the ram might be written after incoming process is finished. Thus
> > + * the memory backend can't be reused for 2nd/3rd... incoming
> > + */
> > + if (backend->share && migrate_ignore_shared()
> > + && runstate_check(RUN_STATE_INMIGRATE))
> > + warn_report("share=on for memory backend file might be "
> > + "conflicted with incoming in ignore shared
> case");
> > +
> > backend->force_prealloc = mem_prealloc;
> > name = host_memory_backend_get_name(backend);
> > memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
>
>
