Re: [Qemu-devel] [PATCH for-2.10] hw/display/sm501: Don't use vmstate_register_ram_global()

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Peter Maydell (peter.maydell@linaro.org) wrote:
> Ping for review, please? Would be nice to get this into rc0.

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

> 
> thanks
> -- PMM
> 
> On 17 July 2017 at 17:37, Peter Maydell <peter.maydell@linaro.org> wrote:
> > The sm501 device uses vmstate_register_ram_global() to register its
> > memory region for migration.  This means it gets a name that is
> > assumed to be global to the whole system, which in turn means that if
> > you create two of the device we assert because of the duplication:
> >
> > qemu-system-ppc -device sm501 -device sm501
> > RAMBlock "sm501.local" already registered, abort!
> > Aborted (core dumped)
> >
> > Changing this to just use memory_region_init_ram()'s automatic
> > registration of the memory region with a device-local name fixes
> > this.  The downside is that it breaks migration compatibility, but
> > luckily we only added migration support to this device in the 2.10
> > release cycle so we haven't released a QEMU version with the broken
> > implementation.
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > ---
> > Recent refactoring that renamed the old "memory_region_init_ram"
> > to memory_region_init_ram_nomigrate" made this bug a bit easier
> > to find via grep...
> >
> >  hw/display/sm501.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/hw/display/sm501.c b/hw/display/sm501.c
> > index af792c5..9aa515b 100644
> > --- a/hw/display/sm501.c
> > +++ b/hw/display/sm501.c
> > @@ -1578,9 +1578,8 @@ static void sm501_init(SM501State *s, DeviceState *dev,
> >                    s->local_mem_size_index);
> >
> >      /* local memory */
> > -    memory_region_init_ram_nomigrate(&s->local_mem_region, OBJECT(dev), "sm501.local",
> > +    memory_region_init_ram(&s->local_mem_region, OBJECT(dev), "sm501.local",
> >                             get_local_mem_size(s), &error_fatal);
> > -    vmstate_register_ram_global(&s->local_mem_region);
> >      memory_region_set_log(&s->local_mem_region, true, DIRTY_MEMORY_VGA);
> >      s->local_mem = memory_region_get_ram_ptr(&s->local_mem_region);
> >
> > --P
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK