On Mon, Dec 18, 2023 at 10:57 PM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
> Enabling a profile and then disabling some of its mandatory extensions
> is a valid use. It can be useful for debugging and testing. But the
> common expected use of enabling a profile is to enable all its mandatory
> extensions.
>
> Add an user warning when mandatory extensions from an enabled profile
> are disabled in the command line. We're also going to disable the
> profile flag in this case since the profile must include all the
> mandatory extensions. This flag can be exposed by QMP to indicate the
> actual profile state after the CPU is realized.
>
> After this patch, this will throw warnings:
>
> -cpu rv64,rva22u64=true,zihintpause=false,zicbom=false,zicboz=false
>
> qemu-system-riscv64: warning: Profile rva22u64 mandates disabled extension zihintpause
> qemu-system-riscv64: warning: Profile rva22u64 mandates disabled extension zicbom
> qemu-system-riscv64: warning: Profile rva22u64 mandates disabled extension zicboz
>
> Note that the following will NOT throw warnings because the profile is
> being enabled last, hence all its mandatory extensions will be enabled:
>
> -cpu rv64,zihintpause=false,zicbom=false,zicboz=false,rva22u64=true
>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> target/riscv/tcg/tcg-cpu.c | 69 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 69 insertions(+)
>
> diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
> index c9df783c51..005d8be26b 100644
> --- a/target/riscv/tcg/tcg-cpu.c
> +++ b/target/riscv/tcg/tcg-cpu.c
> @@ -147,6 +147,26 @@ static int cpu_cfg_ext_get_min_version(uint32_t ext_offset)
> g_assert_not_reached();
> }
>
> +static const char *cpu_cfg_ext_get_name(uint32_t ext_offset)
> +{
> + const RISCVCPUMultiExtConfig *feat;
> + const RISCVIsaExtData *edata;
> +
> + for (edata = isa_edata_arr; edata->name != NULL; edata++) {
> + if (edata->ext_enable_offset == ext_offset) {
> + return edata->name;
> + }
> + }
> +
> + for (feat = riscv_cpu_named_features; feat->name != NULL; feat++) {
> + if (feat->offset == ext_offset) {
> + return feat->name;
> + }
> + }
> +
> + g_assert_not_reached();
> +}
> +
> static bool cpu_cfg_offset_is_named_feat(uint32_t ext_offset)
> {
> const RISCVCPUMultiExtConfig *feat;
> @@ -727,6 +747,54 @@ void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
> riscv_cpu_disable_priv_spec_isa_exts(cpu);
> }
>
> +static void riscv_cpu_validate_profile(RISCVCPU *cpu,
> + RISCVCPUProfile *profile)
> +{
> + const char *warn_msg = "Profile %s mandates disabled extension %s";
> + bool send_warn = profile->user_set && profile->enabled;
> + bool profile_impl = true;
> + int i;
> +
> + for (i = 0; misa_bits[i] != 0; i++) {
> + uint32_t bit = misa_bits[i];
> +
> + if (!(profile->misa_ext & bit)) {
> + continue;
> + }
> +
> + if (!riscv_has_ext(&cpu->env, bit)) {
> + profile_impl = false;
> +
> + if (send_warn) {
> + warn_report(warn_msg, profile->name,
> + riscv_get_misa_ext_name(bit));
> + }
> + }
> + }
> +
> + for (i = 0; profile->ext_offsets[i] != RISCV_PROFILE_EXT_LIST_END; i++) {
> + int ext_offset = profile->ext_offsets[i];
> +
> + if (!isa_ext_is_enabled(cpu, ext_offset)) {
> + profile_impl = false;
> +
> + if (send_warn) {
> + warn_report(warn_msg, profile->name,
> + cpu_cfg_ext_get_name(ext_offset));
> + }
> + }
> + }
> +
> + profile->enabled = profile_impl;
> +}
> +
> +static void riscv_cpu_validate_profiles(RISCVCPU *cpu)
> +{
> + for (int i = 0; riscv_profiles[i] != NULL; i++) {
> + riscv_cpu_validate_profile(cpu, riscv_profiles[i]);
> + }
> +}
> +
> void riscv_tcg_cpu_finalize_features(RISCVCPU *cpu, Error **errp)
> {
> CPURISCVState *env = &cpu->env;
> @@ -745,6 +813,7 @@ void riscv_tcg_cpu_finalize_features(RISCVCPU *cpu, Error **errp)
> }
>
> riscv_cpu_update_named_features(cpu);
> + riscv_cpu_validate_profiles(cpu);
>
> if (cpu->cfg.ext_smepmp && !cpu->cfg.pmp) {
> /*
> --
> 2.43.0
>
>