Re: [PATCH 2/3] target/arm: Avoid assertion trying to use KVM and multiple ASes

[Philippe Mathieu-Daudé]

On 8/16/21 3:58 PM, Peter Maydell wrote:
> KVM cannot support multiple address spaces per CPU; if you try to
> create more than one then cpu_address_space_init() will assert.
> 
> In the Arm CPU realize function, detect the configurations which
> would cause us to need more than one AS, and cleanly fail the
> realize rather than blundering on into the assertion. This
> turns this:
>   $ qemu-system-aarch64  -enable-kvm -display none -cpu max -machine raspi3b
>   qemu-system-aarch64: ../../softmmu/physmem.c:747: cpu_address_space_init: 
> Assertion `asidx == 0 || !kvm_enabled()' failed.
>   Aborted
> 
> into:
>   $ qemu-system-aarch64  -enable-kvm -display none -machine raspi3b
>   qemu-system-aarch64: Cannot enable KVM when guest CPU has EL3 enabled
> 
> and this:
>   $ qemu-system-aarch64  -enable-kvm -display none -machine mps3-an524
>   qemu-system-aarch64: ../../softmmu/physmem.c:747: cpu_address_space_init: 
> Assertion `asidx == 0 || !kvm_enabled()' failed.
>   Aborted
> 
> into:
>   $ qemu-system-aarch64  -enable-kvm -display none -machine mps3-an524
>   qemu-system-aarch64: Cannot enable KVM when using an M-profile guest CPU
> 
> Fixes: https://gitlab.com/qemu-project/qemu/-/issues/528
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target/arm/cpu.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>