Re: [Qemu-devel] [PATCH v4 0/5] Add a valid_cpu_types property

[Peter Maydell <peter.maydell@linaro.org>]

On 20 December 2017 at 00:27, Alistair Francis
<alistair.francis@xilinx.com> wrote:
> There are numorous QEMU machines that only have a single or a handful of
> valid CPU options. To simplyfy the management of specificying which CPU
> is/isn't valid let's create a property that can be set in the machine
> init. We can then check to see if the user supplied CPU is in that list
> or not.
>
> I have added the valid_cpu_types for some ARM machines only at the
> moment.
>
> Here is what specifying the CPUs looks like now:
>
> $ aarch64-softmmu/qemu-system-aarch64 -M netduino2 -kernel ./u-boot.elf -nographic -cpu "cortex-m3" -S
> QEMU 2.10.50 monitor - type 'help' for more information
> (qemu) info cpus
> * CPU #0: thread_id=24175
> (qemu) q
>
> $ aarch64-softmmu/qemu-system-aarch64 -M netduino2 -kernel ./u-boot.elf -nographic -cpu "cortex-m4" -S
> QEMU 2.10.50 monitor - type 'help' for more information
> (qemu) q
>
> $ aarch64-softmmu/qemu-system-aarch64 -M netduino2 -kernel ./u-boot.elf -nographic -cpu "cortex-m5" -S
> qemu-system-aarch64: unable to find CPU model 'cortex-m5'
>
> $ aarch64-softmmu/qemu-system-aarch64 -M netduino2 -kernel ./u-boot.elf -nographic -cpu "cortex-a9" -S
> qemu-system-aarch64: Invalid CPU type: cortex-a9-arm-cpu
> The valid types are: cortex-m3-arm-cpu, cortex-m4-arm-cpu

Thanks for this; we really should be more strict about
forbidding "won't work" combinations than we have
been in the past.

In the last of these cases, I think that when we
list the invalid CPU type and the valid types
we should use the same names we want the user to
use on the command line, without the "-arm-cpu"
suffixes.

thanks
-- PMM