Hi Radim,

On Tue, Nov 25, 2025 at 11:26 PM Radim Krčmář <[email protected]>
wrote:

> 2025-11-21T13:04:10+08:00, <[email protected]>:
> > From: Frank Chang <[email protected]>
> >
> > mstatus.MPV only records the previous virtualization state, and does not
> > affect pointer masking according to the Zjpm specification.
> >
> > This patch rewrites riscv_pm_get_pmm() to follow the architectural
> > definition of Smmpm, Smnpm, and Ssnpm.
> >
> > The resulting PMM selection logic for each mode is summarized below:
> >
> >   * mstatus.MXR = 1: pointer masking disabled
> >
> >   * Smmpm + Smnpm + Ssnpm:
> >       M-mode:  mseccfg.PMM
> >       S-mode:  menvcfg.PMM
> >       U-mode:  senvcfg.PMM
> >       VS-mode: henvcfg.PMM
> >       VU-mode: senvcfg.PMM
> >
> >   * Smmpm + Smnpm (RVS implemented):
> >       M-mode:  mseccfg.PMM
> >       S-mode:  menvcfg.PMM
> >       U/VS/VU: disabled (Ssnpm not present)
> >
> >   * Smmpm + Smnpm (RVS not implemented):
> >       M-mode:  mseccfg.PMM
> >       U-mode:  menvcfg.PMM
> >       S/VS/VU: disabled (no S-mode)
> >
> >   * Smmpm only:
> >       M-mode:  mseccfg.PMM
> >       Other existing modes: pointer masking disabled
> >
> > Signed-off-by: Frank Chang <[email protected]>
> > Reviewed-by: Daniel Henrique Barboza <[email protected]>
> > ---
> > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> >  RISCVPmPmm riscv_pm_get_pmm(CPURISCVState *env)
> >  {
> >  #ifndef CONFIG_USER_ONLY
> > -    int priv_mode = cpu_address_mode(env);
> > +    int priv_mode;
> > +    bool virt;
> >
> > -    if (get_field(env->mstatus, MSTATUS_MPRV) &&
> > -        get_field(env->mstatus, MSTATUS_MXR)) {
> > +    if (get_field(env->mstatus, MSTATUS_MXR)) {
> >          return PMM_FIELD_DISABLED;
> >      }
>
> MSTATUS_MXR doesn't disable Pointer masking in M-mode, and we also need
> to consider virt, where vsstatus.MXR is in effect as well.
>
> >
> > +    riscv_cpu_eff_priv(env, &priv_mode, &virt);
>
> I think you could put something like this here:
>
>       if ((mode != PRV_M && get_field(env->mstatus, MSTATUS_MXR)) ||
>           (virt && get_field(env->vsstatus, MSTATUS_MXR))) {
>           return PMM_FIELD_DISABLED;
>       }
>
> >      /* Get current PMM field */
> >      switch (priv_mode) {
> >      case PRV_M:
> > @@ -189,22 +222,30 @@ RISCVPmPmm riscv_pm_get_pmm(CPURISCVState *env)
> >      case PRV_U:
> > -        if (riscv_has_ext(env, RVS)) {
> > +        if (!virt) {
> >              if (riscv_cpu_cfg(env)->ext_ssnpm) {
> >                  return get_field(env->senvcfg, SENVCFG_PMM);
> >              }
> > -        } else {
> > +
> >              if (riscv_cpu_cfg(env)->ext_smnpm) {
> > -                return get_field(env->menvcfg, MENVCFG_PMM);
> > +                if (!riscv_has_ext(env, RVS)) {
> > +                    return get_field(env->menvcfg, MENVCFG_PMM);
> > +                }
> > +            }
> > +        } else {
> > +            if (riscv_cpu_cfg(env)->ext_ssnpm) {
> > +                return get_field(env->senvcfg, SENVCFG_PMM);
> >              }
> >          }
>
> virt doesn't really matter, the original code was correct.
>
> Thanks.
>

Thanks for the review, I've sent out the v3 patchset:
https://patchew.org/QEMU/[email protected]/

Regards,
Frank Chang

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