Re: [Qemu-devel] [PATCH v2 for-4.1] hw/arm/raspi: Diagnose requests for too much RAM

[Peter Maydell]

On Thu, 28 Mar 2019 at 21:29, Wainer dos Santos Moschetta
<address@hidden> wrote:
>
>
> On 03/28/2019 12:29 PM, Peter Maydell wrote:
> > The Raspberry Pi boards have a physical memory map which does
> > not allow for more than 1GB of RAM. Currently if the user tries
> > to ask for more then we fail in a confusing way:
> >
> > $ qemu-system-aarch64 --machine raspi3 -m 8G
> > Unexpected error in visit_type_uintN() at qapi/qapi-visit-core.c:164:
> > qemu-system-aarch64: Parameter 'vcram-base' expects uint32_t
> > Aborted (core dumped)
> >
> > Catch this earlier and diagnose it with a more friendly message:
> > $ qemu-system-aarch64 --machine raspi3 -m 8G
> > qemu-system-aarch64: Requested ram size is too large for this machine: 
> > maximum is 1GB
> >
> > Fixes: https://bugs.launchpad.net/qemu/+bug/1794187
> > Signed-off-by: Peter Maydell <address@hidden>
> > ---
> > Changes v1->v2: use '>', not '>='...
> >
> >   hw/arm/raspi.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
> > index 66899c28dc1..fe2bb511b98 100644
> > --- a/hw/arm/raspi.c
> > +++ b/hw/arm/raspi.c
> > @@ -12,6 +12,7 @@
> >    */
> >
> >   #include "qemu/osdep.h"
> > +#include "qemu/units.h"
> >   #include "qapi/error.h"
> >   #include "qemu-common.h"
> >   #include "cpu.h"
> > @@ -175,6 +176,12 @@ static void raspi_init(MachineState *machine, int 
> > version)
> >       BusState *bus;
> >       DeviceState *carddev;
> >
> > +    if (machine->ram_size > 1 * GiB) {
> > +        error_report("Requested ram size is too large for this machine: "
> > +                     "maximum is 1GB");
>
> 1GB vs 1GiB... maybe the message should display "GiB" to avoid any
> confusion?

I don't know why we call our #defined constant GiB -- to me
the unit is GB and I think printing anything else in user
messages is weird.

thanks
-- PMM