Re: [PATCH 08/13] hw/arm/mps3r: Initial skeleton for mps3-an536 board

[Cédric Le Goater]

> > > +/*
> > > + * The MPS3 DDR is 3GiB, but on a 32-bit host QEMU doesn't permit
> > > + * emulation of that much guest RAM, so artificially make it smaller.
> > > + */
> > > +#if HOST_LONG_BITS == 32
> > > +#define MPS3_DDR_SIZE (1 * GiB)
> > > +#else
> > > +#define MPS3_DDR_SIZE (3 * GiB)
> > > +#endif
> >
> > Generically, can we migrate a VM started on a 32-bit host to a 64-bit
> > one?
>
> I think it's one of those things that in theory is supposed
> to be possible and in practice nobody tests so it might well
> not work. At any rate, this is the same thing we do already
> in mps2-tz.c for the 2GB DRAM those boards have.

We could have a common helper may be. Aspeed does:

  /* On 32-bit hosts, lower RAM to 1G because of the 2047 MB limit */
  #if HOST_LONG_BITS == 32
  #define ASPEED_RAM_SIZE(sz) MIN((sz), 1 * GiB)
  #else
  #define ASPEED_RAM_SIZE(sz) (sz)
  #endif

Thanks,

C.