Re: [PATCH v4 2/9] target/riscv/kvm: add 'rva22u64' flag as unavailable

[Andrew Jones]

On Wed, Oct 25, 2023 at 10:49:54AM -0300, Daniel Henrique Barboza wrote:
> KVM does not have the means to support enabling the rva22u64 profile.
> The main reasons are:
> 
> - we're missing support for some mandatory rva22u64 extensions in the
>   KVM module;
> 
> - we can't make promises about enabling a profile since it all depends
>   on host support in the end.
> 
> We'll revisit this decision in the future if needed. For now mark the
> 'rva22u64' profile as unavailable when running a KVM CPU:
> 
> $ qemu-system-riscv64 -machine virt,accel=kvm -cpu rv64,rva22u64=true
> qemu-system-riscv64: can't apply global rv64-riscv-cpu.rva22u64=true:
>     'rva22u64' is not available with KVM
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> ---
>  target/riscv/kvm/kvm-cpu.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
> index 6d1c0a7915..2243dfde64 100644
> --- a/target/riscv/kvm/kvm-cpu.c
> +++ b/target/riscv/kvm/kvm-cpu.c
> @@ -393,7 +393,7 @@ static void cpu_set_cfg_unavailable(Object *obj, Visitor 
> *v,
>      }
>  
>      if (value) {
> -        error_setg(errp, "extension %s is not available with KVM",
> +        error_setg(errp, "'%s' is not available with KVM",
>                     propname);
>      }
>  }
> @@ -474,6 +474,11 @@ static void kvm_riscv_add_cpu_user_properties(Object 
> *cpu_obj)
>      riscv_cpu_add_kvm_unavail_prop_array(cpu_obj, riscv_cpu_extensions);
>      riscv_cpu_add_kvm_unavail_prop_array(cpu_obj, riscv_cpu_vendor_exts);
>      riscv_cpu_add_kvm_unavail_prop_array(cpu_obj, 
> riscv_cpu_experimental_exts);
> +
> +   /* We don't have the needed KVM support for profiles */
> +    for (i = 0; riscv_profiles[i] != NULL; i++) {
> +        riscv_cpu_add_kvm_unavail_prop(cpu_obj, riscv_profiles[i]->name);
> +    }
>  }
>  
>  static int kvm_riscv_get_regs_core(CPUState *cs)
> -- 
> 2.41.0
> 
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>