[QEMU-PPC,V3,4/6] target/ppc/spapr_caps: Add new tristate cap safe_bounds_check

Add new tristate cap cap-sbbc to represent the speculation barrier
bounds checking capability.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
---
 hw/ppc/spapr.c         |  2 ++
 hw/ppc/spapr_caps.c    | 39 +++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h |  5 ++++-
 3 files changed, 45 insertions(+), 1 deletion(-)

On Mon, Jan 15, 2018 at 05:32:33PM +1100, Suraj Jitindar Singh wrote:
> Add new tristate cap cap-sbbc to represent the speculation barrier
> bounds checking capability.
> 
> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  hw/ppc/spapr.c         |  2 ++
>  hw/ppc/spapr_caps.c    | 39 +++++++++++++++++++++++++++++++++++++++
>  include/hw/ppc/spapr.h |  5 ++++-
>  3 files changed, 45 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 5d62dc9968..02a0cb656b 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1792,6 +1792,7 @@ static const VMStateDescription vmstate_spapr = {
>          &vmstate_spapr_cap_vsx,
>          &vmstate_spapr_cap_dfp,
>          &vmstate_spapr_cap_cfpc,
> +        &vmstate_spapr_cap_sbbc,
>          NULL
>      }
>  };
> @@ -3865,6 +3866,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>      smc->default_caps.caps[SPAPR_CAP_VSX] = SPAPR_CAP_ON;
>      smc->default_caps.caps[SPAPR_CAP_DFP] = SPAPR_CAP_ON;
>      smc->default_caps.caps[SPAPR_CAP_CFPC] = SPAPR_CAP_BROKEN;
> +    smc->default_caps.caps[SPAPR_CAP_SBBC] = SPAPR_CAP_BROKEN;
>      spapr_caps_add_properties(smc, &error_abort);
>  }
>  
> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
> index bc2b2c3590..518e019cf7 100644
> --- a/hw/ppc/spapr_caps.c
> +++ b/hw/ppc/spapr_caps.c
> @@ -191,6 +191,17 @@ static void cap_safe_cache_apply(sPAPRMachineState *spapr, uint8_t val,
>      }
>  }
>  
> +static void cap_safe_bounds_check_apply(sPAPRMachineState *spapr, uint8_t val,
> +                                        Error **errp)
> +{
> +    if (tcg_enabled() && val) {
> +        /* TODO - for now only allow broken for TCG */
> +        error_setg(errp, "Requested safe bounds check capability level not supported by tcg, try a different value for cap-sbbc");
> +    } else if (kvm_enabled() && (val > kvmppc_get_cap_safe_bounds_check())) {
> +        error_setg(errp, "Requested safe bounds check capability level not supported by kvm, try a different value for cap-sbbc");
> +    }
> +}
> +
>  #define VALUE_DESC_TRISTATE     " (broken, workaround, fixed)"
>  
>  sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
> @@ -230,6 +241,15 @@ sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
>          .type = "string",
>          .apply = cap_safe_cache_apply,
>      },
> +    [SPAPR_CAP_SBBC] = {
> +        .name = "sbbc",
> +        .description = "Speculation Barrier Bounds Checking" VALUE_DESC_TRISTATE,
> +        .index = SPAPR_CAP_SBBC,
> +        .get = spapr_cap_get_tristate,
> +        .set = spapr_cap_set_tristate,
> +        .type = "string",
> +        .apply = cap_safe_bounds_check_apply,
> +    },
>  };
>  
>  static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
> @@ -385,6 +405,25 @@ const VMStateDescription vmstate_spapr_cap_cfpc = {
>      },
>  };
>  
> +static bool spapr_cap_sbbc_needed(void *opaque)
> +{
> +    sPAPRMachineState *spapr = opaque;
> +
> +    return spapr->cmd_line_caps[SPAPR_CAP_SBBC] &&
> +           (spapr->eff.caps[SPAPR_CAP_SBBC] != spapr->def.caps[SPAPR_CAP_SBBC]);
> +}
> +
> +const VMStateDescription vmstate_spapr_cap_sbbc = {
> +    .name = "spapr/cap/sbbc",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .needed = spapr_cap_sbbc_needed,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT8(mig.caps[SPAPR_CAP_SBBC], sPAPRMachineState),
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
>  void spapr_caps_reset(sPAPRMachineState *spapr)
>  {
>      sPAPRCapabilities default_caps;
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index ff476693d1..c65be62e92 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -62,8 +62,10 @@ typedef enum {
>  #define SPAPR_CAP_DFP                   0x02
>  /* Cache Flush on Privilege Change */
>  #define SPAPR_CAP_CFPC                  0x03
> +/* Speculation Barrier Bounds Checking */
> +#define SPAPR_CAP_SBBC                  0x04
>  /* Num Caps */
> -#define SPAPR_CAP_NUM                   (SPAPR_CAP_CFPC + 1)
> +#define SPAPR_CAP_NUM                   (SPAPR_CAP_SBBC + 1)
>  
>  /*
>   * Capability Values
> @@ -782,6 +784,7 @@ extern const VMStateDescription vmstate_spapr_cap_htm;
>  extern const VMStateDescription vmstate_spapr_cap_vsx;
>  extern const VMStateDescription vmstate_spapr_cap_dfp;
>  extern const VMStateDescription vmstate_spapr_cap_cfpc;
> +extern const VMStateDescription vmstate_spapr_cap_sbbc;
>  
>  static inline uint8_t spapr_get_cap(sPAPRMachineState *spapr, int cap)
>  {