Re: [kvm-unit-tests PATCH v2 13/18] run_tests: Do not probe for maximum number of VCPUs when using kvmtool

[Andrew Jones <andrew.jones@linux.dev>]

On Mon, Jan 20, 2025 at 04:43:11PM +0000, Alexandru Elisei wrote:
> The --probe-maxsmp parameter updates MAX_SMP with the maximum number of
> VCPUs that the host supports. Qemu will exit with an error when creating a
> virtual machine if the number of VCPUs is exceeded.
> 
> kvmtool behaves differently: it will automatically limit the number of
> VCPUs to the what KVM supports, which is exactly what --probe-maxsmp wants
> to achieve. When doing --probe-maxsmp with kvmtool, print a message
> explaining why it's redundant and don't do anything else.
> 
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> ---
>  run_tests.sh | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/run_tests.sh b/run_tests.sh
> index 61480d0c05ed..acaaadbb879b 100755
> --- a/run_tests.sh
> +++ b/run_tests.sh
> @@ -89,7 +89,15 @@ while [ $# -gt 0 ]; do
>              list_tests="yes"
>              ;;
>          --probe-maxsmp)
> -            probe_maxsmp
> +            case "$TARGET" in
> +            qemu)
> +                probe_maxsmp
> +                ;;
> +            kvmtool)
> +                echo "kvmtool automatically limits the number of VCPUs to maximum supported"
> +                echo "The 'smp' test parameter won't be modified"
> +                ;;
> +            esac
>              ;;
>          --)
>              ;;
> -- 
> 2.47.1
>

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>

but I hope we can do something with the associative array idea to
avoid all the TARGET case statements that are getting scattered
around. Here, we could rename probe_maxsmp to qemu_probe_maxmp and
then add kvmtool_probe_maxsmp which does this output and each
to their respective vmm[$vmm,probe_maxsmp] member.

Thanks,
drew