Re: [RFC 2/2] target/riscv: Add server platform reference cpu

[Daniel Henrique Barboza <dbarboza@ventanamicro.com>]

On 3/4/24 07:25, Fei Wu wrote:
> The harts requirements of RISC-V server platform [1] require RVA23 ISA
> profile support, plus Sv48, Svadu, H, Sscofmpf etc. This patch provides
> a virt CPU type (rvsp-ref) as compliant as possible.
> 
> [1] https://github.com/riscv-non-isa/riscv-server-platform/blob/main/server_platform_requirements.adoc
> 
> Signed-off-by: Fei Wu <fei2.wu@intel.com>
> --->   hw/riscv/server_platform_ref.c |  6 +++-
>   target/riscv/cpu-qom.h         |  1 +
>   target/riscv/cpu.c             | 62 ++++++++++++++++++++++++++++++++++
>   3 files changed, 68 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/riscv/server_platform_ref.c b/hw/riscv/server_platform_ref.c
> index ae90c4b27a..52ec607cee 100644
> --- a/hw/riscv/server_platform_ref.c
> +++ b/hw/riscv/server_platform_ref.c
> @@ -1205,11 +1205,15 @@ static void rvsp_ref_machine_class_init(ObjectClass *oc, void *data)
>   {
>       char str[128];
>       MachineClass *mc = MACHINE_CLASS(oc);
> +    static const char * const valid_cpu_types[] = {
> +        TYPE_RISCV_CPU_RVSP_REF,
> +    };
>   
>       mc->desc = "RISC-V Server SoC Reference board";
>       mc->init = rvsp_ref_machine_init;
>       mc->max_cpus = RVSP_CPUS_MAX;
> -    mc->default_cpu_type = TYPE_RISCV_CPU_BASE;
> +    mc->default_cpu_type = TYPE_RISCV_CPU_RVSP_REF;
> +    mc->valid_cpu_types = valid_cpu_types;

I suggest introducing this patch first, then the new machine type that will use it as a default
CPU. The reason is to facilitate future bisects. If we introduce the board first, a future bisect
might hit the previous patch, the board will be run using RV64 instead of the correct CPU, and
we'll have different results because of it.

>       mc->pci_allow_0_address = true;
>       mc->default_nic = "e1000e";
>       mc->possible_cpu_arch_ids = riscv_numa_possible_cpu_arch_ids;
> diff --git a/target/riscv/cpu-qom.h b/target/riscv/cpu-qom.h
> index 3670cfe6d9..adb934d19e 100644
> --- a/target/riscv/cpu-qom.h
> +++ b/target/riscv/cpu-qom.h
> @@ -49,6 +49,7 @@
>   #define TYPE_RISCV_CPU_SIFIVE_U54       RISCV_CPU_TYPE_NAME("sifive-u54")
>   #define TYPE_RISCV_CPU_THEAD_C906       RISCV_CPU_TYPE_NAME("thead-c906")
>   #define TYPE_RISCV_CPU_VEYRON_V1        RISCV_CPU_TYPE_NAME("veyron-v1")
> +#define TYPE_RISCV_CPU_RVSP_REF         RISCV_CPU_TYPE_NAME("rvsp-ref")
>   #define TYPE_RISCV_CPU_HOST             RISCV_CPU_TYPE_NAME("host")
>   
>   OBJECT_DECLARE_CPU_TYPE(RISCVCPU, RISCVCPUClass, RISCV_CPU)
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 5ff0192c52..bc91be702b 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -2282,6 +2282,67 @@ static void rva22s64_profile_cpu_init(Object *obj)
>   
>       RVA22S64.enabled = true;
>   }
> +
> +static void rv64_rvsp_ref_cpu_init(Object *obj)
> +{
> +    CPURISCVState *env = &RISCV_CPU(obj)->env;
> +    RISCVCPU *cpu = RISCV_CPU(obj);
> +
> +    riscv_cpu_set_misa_ext(env, RVG | RVC | RVS | RVU | RVH | RVV);
> +
> +    /* FIXME: change to 1.13 */
> +    env->priv_ver = PRIV_VERSION_1_12_0;
> +
> +    /* RVA22U64 */
> +    cpu->cfg.mmu = true;
> +    cpu->cfg.ext_zifencei = true;
> +    cpu->cfg.ext_zicsr = true;
> +    cpu->cfg.ext_zicntr = true;
> +    cpu->cfg.ext_zihpm = true;
> +    cpu->cfg.ext_zihintpause = true;
> +    cpu->cfg.ext_zba = true;
> +    cpu->cfg.ext_zbb = true;
> +    cpu->cfg.ext_zbs = true;
> +    cpu->cfg.zic64b = true;
> +    cpu->cfg.ext_zicbom = true;
> +    cpu->cfg.ext_zicbop = true;
> +    cpu->cfg.ext_zicboz = true;
> +    cpu->cfg.cbom_blocksize = 64;
> +    cpu->cfg.cbop_blocksize = 64;
> +    cpu->cfg.cboz_blocksize = 64;
> +    cpu->cfg.ext_zfhmin = true;
> +    cpu->cfg.ext_zkt = true;

You can change this whole block with:

RVA22U64.enabled = true;


riscv_cpu_add_profiles() will check if we have a profile enabled and, if that's the
case, we'll enable all its extensions in the CPU.

In the near future, when we implement a proper RVA23 support, we'll be able to just do
a single RVA23S64.enabled = true in this cpu_init(). But for now we can at least declare
RVA22U64 (perhaps RVA22S64) support for this CPU.


Thanks,

Daniel


> +
> +    /* RVA23U64 */
> +    cpu->cfg.ext_zvfhmin = true;
> +    cpu->cfg.ext_zvbb = true;
> +    cpu->cfg.ext_zvkt = true;
> +    cpu->cfg.ext_zihintntl = true;
> +    cpu->cfg.ext_zicond = true;
> +    cpu->cfg.ext_zcb = true;
> +    cpu->cfg.ext_zfa = true;
> +    cpu->cfg.ext_zawrs = true;
> +
> +    /* RVA23S64 */
> +    cpu->cfg.ext_zifencei = true;
> +    cpu->cfg.svade = true;
> +    cpu->cfg.ext_svpbmt = true;
> +    cpu->cfg.ext_svinval = true;
> +    cpu->cfg.ext_svnapot = true;
> +    cpu->cfg.ext_sstc = true;
> +    cpu->cfg.ext_sscofpmf = true;
> +    cpu->cfg.ext_smstateen = true;
> +
> +    cpu->cfg.ext_smaia = true;
> +    cpu->cfg.ext_ssaia = true;
> +
> +    /* Server Platform */
> +#ifndef CONFIG_USER_ONLY
> +    set_satp_mode_max_supported(cpu, VM_1_10_SV48);
> +#endif
> +    cpu->cfg.ext_svadu = true;
> +    cpu->cfg.ext_zkr = true;
> +}
>   #endif
>   
>   static const gchar *riscv_gdb_arch_name(CPUState *cs)
> @@ -2547,6 +2608,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
>       DEFINE_BARE_CPU(TYPE_RISCV_CPU_RV64E,        MXL_RV64,  rv64e_bare_cpu_init),
>       DEFINE_PROFILE_CPU(TYPE_RISCV_CPU_RVA22U64,  MXL_RV64,  rva22u64_profile_cpu_init),
>       DEFINE_PROFILE_CPU(TYPE_RISCV_CPU_RVA22S64,  MXL_RV64,  rva22s64_profile_cpu_init),
> +    DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_RVSP_REF,   MXL_RV64,  rv64_rvsp_ref_cpu_init),
>   #endif
>   };
>