Re: [Qemu-devel] [PATCH for-4.0] hw/arm/raspi: Diagnose requests for too much RAM

[Peter Maydell]

On Thu, 28 Mar 2019 at 09:57, Peter Maydell <address@hidden> 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>
> ---
>  hw/arm/raspi.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
> index 66899c28dc1..c7a18a319bc 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");
> +        exit(1);
> +    }

No patch is so simple that it can't have a bug or that it's
not necessary to run 'make check'. The condition in the if()
should be ">", not ">=", as 1GB is both valid and the default...

thanks
-- PMM