On Thu, Apr 24, 2025 at 09:01:59PM +0530, Anup Patel wrote:
> It is useful to allow including extensions in the min CPU type on need
> basis via command-line. To achieve this, parse extension names as comma
> separated values appended to the "min" CPU type using command-line.
>
> For example, to include Sstc and Ssaia in the min CPU type use
> "--cpu-type min,sstc,ssaia" command-line option.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> riscv/fdt.c | 43 ++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 40 insertions(+), 3 deletions(-)
>
> diff --git a/riscv/fdt.c b/riscv/fdt.c
> index 5d9b9bf..722493a 100644
> --- a/riscv/fdt.c
> +++ b/riscv/fdt.c
> @@ -108,6 +108,20 @@ static bool __isa_ext_warn_disable_failure(struct kvm *kvm, struct isa_ext_info
> return true;
> }
>
> +static void __min_enable(const char *ext, size_t ext_len)
> +{
> + struct isa_ext_info *info;
> + unsigned long i;
> +
> + for (i = 0; i < ARRAY_SIZE(isa_info_arr); i++) {
> + info = &isa_info_arr[i];
> + if (strlen(info->name) != ext_len)
> + continue;
> + if (!strncmp(ext, info->name, ext_len))
Just strcmp since we already checked the length and wouldn't want
something like info->name = mmmmnnnn to match ext = mmmm anyway.
> + info->min_enabled = true;
> + }
> +}
> +
> bool riscv__isa_extension_disabled(struct kvm *kvm, unsigned long isa_ext_id)
> {
> struct isa_ext_info *info = NULL;
> @@ -128,15 +142,38 @@ bool riscv__isa_extension_disabled(struct kvm *kvm, unsigned long isa_ext_id)
> int riscv__cpu_type_parser(const struct option *opt, const char *arg, int unset)
> {
> struct kvm *kvm = opt->ptr;
> + const char *str, *nstr;
> + int len;
>
> - if ((strncmp(arg, "min", 3) && strncmp(arg, "max", 3)) || strlen(arg) != 3)
> + if ((strncmp(arg, "min", 3) || strlen(arg) < 3) &&
The strlen(arg) < 3 will never be true because if strncmp(arg, "min", 3)
returns 0 (false), then that means arg starts with 'min', and therefore
can't have a length less than 3. And, if strncmp(arg, "min", 3) returns
nonzero, then the '|| expression' will be short-circuited.
> + (strncmp(arg, "max", 3) || strlen(arg) != 3))
So
if (strncmp(arg, "min", 3) && (strncmp(arg, "max", 3) || strlen(arg) != 3))
should do it.
> die("Invalid CPU type %s\n", arg);
>
> - if (!strcmp(arg, "max"))
> + if (!strcmp(arg, "max")) {
> kvm->cfg.arch.cpu_type = RISCV__CPU_TYPE_MAX;
> - else
> + } else {
> kvm->cfg.arch.cpu_type = RISCV__CPU_TYPE_MIN;
>
> + str = arg;
> + str += 3;
> + while (*str) {
> + if (*str == ',') {
> + str++;
> + continue;
> + }
> +
> + nstr = strchr(str, ',');
> + if (!nstr)
> + nstr = str + strlen(str);
> +
> + len = nstr - str;
> + if (len) {
> + __min_enable(str, len);
> + str += len;
> + }
> + }
> + }
> +
> return 0;
> }
>
> --
> 2.43.0
>
Otherwise,
Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
