Re: [PATCH v19 QEMU 4/4] memory: Do not allow direct write access to rom_device regions

[Alexander Duyck <alexander.duyck@gmail.com>]

On Fri, Apr 10, 2020 at 3:50 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 10/04/20 05:41, Alexander Duyck wrote:
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> >
> > According to the documentation in memory.h a ROM memory region will be
> > backed by RAM for reads, but is supposed to go through a callback for
> > writes. Currently we were not checking for the existence of the rom_device
> > flag when determining if we could perform a direct write or not.
> >
> > To correct that add a check to memory_region_is_direct so that if the
> > memory region has the rom_device flag set we will return false for all
> > checks where is_write is set.
> >
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > ---
> >  include/exec/memory.h |    4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/exec/memory.h b/include/exec/memory.h
> > index 1614d9a02c0c..e000bd2f97b2 100644
> > --- a/include/exec/memory.h
> > +++ b/include/exec/memory.h
> > @@ -2351,8 +2351,8 @@ void address_space_write_cached_slow(MemoryRegionCache *cache,
> >  static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
> >  {
> >      if (is_write) {
> > -        return memory_region_is_ram(mr) &&
> > -               !mr->readonly && !memory_region_is_ram_device(mr);
> > +        return memory_region_is_ram(mr) && !mr->readonly &&
> > +               !mr->rom_device && !memory_region_is_ram_device(mr);
> >      } else {
> >          return (memory_region_is_ram(mr) && !memory_region_is_ram_device(mr)) ||
> >                 memory_region_is_romd(mr);
> >
>
> Good catch.  I queued this up for 5.0.
>
> Thanks,
>
> Paolo

Thanks Paolo,

It looks like you only pulled this patch correct?

If so, David & Michael, do I need to resubmit the first 3 in this
series or can those be pulled separately?

Thanks.

Alex