Re: [Qemu-devel] [PATCH v1 08/28] target/riscv: Add Hypervisor CSR access functions

[Palmer Dabbelt <palmer@sifive.com>]

On Fri, 23 Aug 2019 16:38:10 PDT (-0700), Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/csr.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 471f23a1d0..388775d45a 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -98,6 +98,20 @@ static int smode(CPURISCVState *env, int csrno)
>      return -!riscv_has_ext(env, RVS);
>  }
>
> +static int hmode(CPURISCVState *env, int csrno)
> +{
> +    if (riscv_has_ext(env, RVS) &&
> +        riscv_has_ext(env, RVH)) {
> +        /* Hypervisor extension is supported */
> +        if ((env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
> +            env->priv == PRV_M) {
> +            return 0;
> +        }
> +    }
> +
> +    return -1;
> +}
> +
>  static int pmp(CPURISCVState *env, int csrno)
>  {
>      return -!riscv_feature(env, RISCV_FEATURE_PMP);
> @@ -754,6 +768,55 @@ static int write_satp(CPURISCVState *env, int csrno, target_ulong val)
>      return 0;
>  }
>
> +/* Hypervisor Extensions */
> +static int read_hstatus(CPURISCVState *env, int csrno, target_ulong *val)
> +{
> +    *val = env->hstatus;
> +    return 0;
> +}
> +
> +static int write_hstatus(CPURISCVState *env, int csrno, target_ulong val)
> +{
> +    env->hstatus = val;
> +    return 0;
> +}
> +
> +static int read_hedeleg(CPURISCVState *env, int csrno, target_ulong *val)
> +{
> +    *val = env->hedeleg;
> +    return 0;
> +}
> +
> +static int write_hedeleg(CPURISCVState *env, int csrno, target_ulong val)
> +{
> +    env->hedeleg = val;
> +    return 0;
> +}
> +
> +static int read_hideleg(CPURISCVState *env, int csrno, target_ulong *val)
> +{
> +    *val = env->hideleg;
> +    return 0;
> +}
> +
> +static int write_hideleg(CPURISCVState *env, int csrno, target_ulong val)
> +{
> +    env->hideleg = val;
> +    return 0;
> +}
> +
> +static int read_hgatp(CPURISCVState *env, int csrno, target_ulong *val)
> +{
> +    *val = env->hgatp;
> +    return 0;
> +}
> +
> +static int write_hgatp(CPURISCVState *env, int csrno, target_ulong val)
> +{
> +    env->hgatp = val;
> +    return 0;
> +}
> +
>  /* Physical Memory Protection */
>  static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
>  {
> @@ -950,6 +1013,11 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
>      /* Supervisor Protection and Translation */
>      [CSR_SATP] =                { smode, read_satp,        write_satp        },
>
> +    [CSR_HSTATUS] =             { hmode,   read_hstatus,     write_hstatus    },
> +    [CSR_HEDELEG] =             { hmode,   read_hedeleg,     write_hedeleg    },
> +    [CSR_HIDELEG] =             { hmode,   read_hideleg,     write_hideleg    },
> +    [CSR_HGATP] =               { hmode,   read_hgatp,       write_hgatp      },
> +
>      /* Physical Memory Protection */
>      [CSR_PMPCFG0  ... CSR_PMPADDR9] =  { pmp,   read_pmpcfg,  write_pmpcfg   },
>      [CSR_PMPADDR0 ... CSR_PMPADDR15] = { pmp,   read_pmpaddr, write_pmpaddr  },

Reviewed-by: Palmer Dabbelt <palmer@sifive.com>