Re: [PATCH RESEND v2 3/6] target/arm/kvm: Add an option to turn on/off el2 support

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

On Thu, 1 Apr 2021 at 13:55, Haibo Xu <haibo.xu@linaro.org> wrote:
>
> Adds an el2=[on/off] option to enable/disable el2(nested virtualization)
> support in KVM guest vCPU.
>
> Signed-off-by: Haibo Xu <haibo.xu@linaro.org>
> ---
>  target/arm/cpu.c   | 11 ++++++++++
>  target/arm/cpu.h   |  4 ++++
>  target/arm/cpu64.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 67 insertions(+)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index ae04884408..30cc330f50 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -1349,6 +1349,17 @@ void arm_cpu_finalize_features(ARMCPU *cpu, Error **errp)
>                  return;
>              }
>          }
> +
> +        /*
> +         * Currently, vCPU feature 'el2' only supported in KVM mode.
> +         */
> +        if (kvm_enabled()) {
> +            arm_cpu_el2_finalize(cpu, &local_err);
> +            if (local_err != NULL) {
> +                error_propagate(errp, local_err);
> +                return;
> +            }
> +        }

I don't understand this. EL2 is supported in TCG as well...

thanks
-- PMM