Re: [PATCH v4 05/10] hw/arm/smmuv3: Parse STE config for stage-2

[Eric Auger <eric.auger@redhat.com>]

Hi Mostafa,

On 5/16/23 22:33, Mostafa Saleh wrote:
> Parse stage-2 configuration from STE and populate it in SMMUS2Cfg.
> Validity of field values are checked when possible.
>
> Only AA64 tables are supported and Small Translation Tables (STT) are
> not supported.
>
> According to SMMUv3 UM(IHI0070E) "5.2 Stream Table Entry": All fields
> with an S2 prefix (with the exception of S2VMID) are IGNORED when
> stage-2 bypasses translation (Config[1] == 0).
>
> Which means that VMID can be used(for TLB tagging) even if stage-2 is
> bypassed, so we parse it unconditionally when S2P exists. Otherwise
> it is set to -1.(only S1P)
>
> As stall is not supported, if S2S is set the translation would abort.
> For S2R, we reuse the same code used for stage-1 with flag
> record_faults. However when nested translation is supported we would
> need to separate stage-1 and stage-2 faults.
>
> Fix wrong shift in STE_S2HD, STE_S2HA, STE_S2S.
>
> Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
> Changes in V4:
> - Rename and simplify PTW_FAULT_ALLOWED
> - Fix comment indent
> Changes in V3:
> - Separate fault handling.
> - Fix shift in STE_S2HD, STE_S2HA, STE_S2S, STE_S2R.
> - Rename t0sz_valid to s2t0sz_valid.
> - separate stage-2 STE parsing in decode_ste_s2_cfg.
> - Add a log for invalid S2ENDI and S2TTB.
> - Set default value for stage-1 OAS.
> - Move and rename SMMU_MAX_S2_CONCAT to VMSA_MAX_S2_CONCAT.
> Changes in V2:
> - Parse S2PS and S2ENDI
> - Squash with S2VMID parsing patch
> - Squash with S2AFF parsing
> - Squash with fault reporting patch
> - Add check for S2T0SZ
> - Renaming and refactoring code
> ---
>  hw/arm/smmuv3-internal.h     |  10 +-
>  hw/arm/smmuv3.c              | 181 +++++++++++++++++++++++++++++++++--
>  include/hw/arm/smmu-common.h |   1 +
>  include/hw/arm/smmuv3.h      |   3 +
>  4 files changed, 185 insertions(+), 10 deletions(-)
>
> diff --git a/hw/arm/smmuv3-internal.h b/hw/arm/smmuv3-internal.h
> index 183d5ac8dc..6d1c1edab7 100644
> --- a/hw/arm/smmuv3-internal.h
> +++ b/hw/arm/smmuv3-internal.h
> @@ -526,9 +526,13 @@ typedef struct CD {
>  #define STE_S2TG(x)        extract32((x)->word[5], 14, 2)
>  #define STE_S2PS(x)        extract32((x)->word[5], 16, 3)
>  #define STE_S2AA64(x)      extract32((x)->word[5], 19, 1)
> -#define STE_S2HD(x)        extract32((x)->word[5], 24, 1)
> -#define STE_S2HA(x)        extract32((x)->word[5], 25, 1)
> -#define STE_S2S(x)         extract32((x)->word[5], 26, 1)
> +#define STE_S2ENDI(x)      extract32((x)->word[5], 20, 1)
> +#define STE_S2AFFD(x)      extract32((x)->word[5], 21, 1)
> +#define STE_S2HD(x)        extract32((x)->word[5], 23, 1)
> +#define STE_S2HA(x)        extract32((x)->word[5], 24, 1)
> +#define STE_S2S(x)         extract32((x)->word[5], 25, 1)
> +#define STE_S2R(x)         extract32((x)->word[5], 26, 1)
> +
>  #define STE_CTXPTR(x)                                           \
>      ({                                                          \
>          unsigned long addr;                                     \
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index 4e90343996..27840f2d66 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -33,6 +33,9 @@
>  #include "smmuv3-internal.h"
>  #include "smmu-internal.h"
>  
> +#define PTW_RECORD_FAULT(cfg)   (((cfg)->stage == 1) ? (cfg)->record_faults : \
> +                                 (cfg)->s2cfg.record_faults)
> +
>  /**
>   * smmuv3_trigger_irq - pulse @irq if enabled and update
>   * GERROR register in case of GERROR interrupt
> @@ -329,11 +332,141 @@ static int smmu_get_cd(SMMUv3State *s, STE *ste, uint32_t ssid,
>      return 0;
>  }
>  
> +/*
> + * Max valid value is 39 when SMMU_IDR3.STT == 0.
> + * In architectures after SMMUv3.0:
> + * - If STE.S2TG selects a 4KB or 16KB granule, the minimum valid value for this
> + *   field is MAX(16, 64-IAS)
> + * - If STE.S2TG selects a 64KB granule, the minimum valid value for this field
> + *   is (64-IAS).
> + * As we only support AA64, IAS = OAS.
> + */
> +static bool s2t0sz_valid(SMMUTransCfg *cfg)
> +{
> +    if (cfg->s2cfg.tsz > 39) {
> +        return false;
> +    }
> +
> +    if (cfg->s2cfg.granule_sz == 16) {
> +        return (cfg->s2cfg.tsz >= 64 - oas2bits(SMMU_IDR5_OAS));
> +    }
> +
> +    return (cfg->s2cfg.tsz >= MAX(64 - oas2bits(SMMU_IDR5_OAS), 16));
> +}
> +
> +/*
> + * Return true if s2 page table config is valid.
> + * This checks with the configured start level, ias_bits and granularity we can
> + * have a valid page table as described in ARM ARM D8.2 Translation process.
> + * The idea here is to see for the highest possible number of IPA bits, how
> + * many concatenated tables we would need, if it is more than 16, then this is
> + * not possible.
> + */
> +static bool s2_pgtable_config_valid(uint8_t sl0, uint8_t t0sz, uint8_t gran)
> +{
> +    int level = get_start_level(sl0, gran);
> +    uint64_t ipa_bits = 64 - t0sz;
> +    uint64_t max_ipa = (1ULL << ipa_bits) - 1;
> +    int nr_concat = pgd_concat_idx(level, gran, max_ipa) + 1;
> +
> +    return nr_concat <= VMSA_MAX_S2_CONCAT;
> +}
> +
> +static int decode_ste_s2_cfg(SMMUTransCfg *cfg, STE *ste)
> +{
> +    cfg->stage = 2;
> +
> +    if (STE_S2AA64(ste) == 0x0) {
> +        qemu_log_mask(LOG_UNIMP,
> +                      "SMMUv3 AArch32 tables not supported\n");
> +        g_assert_not_reached();
> +    }
> +
> +    switch (STE_S2TG(ste)) {
> +    case 0x0: /* 4KB */
> +        cfg->s2cfg.granule_sz = 12;
> +        break;
> +    case 0x1: /* 64KB */
> +        cfg->s2cfg.granule_sz = 16;
> +        break;
> +    case 0x2: /* 16KB */
> +        cfg->s2cfg.granule_sz = 14;
> +        break;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "SMMUv3 bad STE S2TG: %x\n", STE_S2TG(ste));
> +        goto bad_ste;
> +    }
> +
> +    cfg->s2cfg.vttb = STE_S2TTB(ste);
> +
> +    cfg->s2cfg.sl0 = STE_S2SL0(ste);
> +    /* FEAT_TTST not supported. */
> +    if (cfg->s2cfg.sl0 == 0x3) {
> +        qemu_log_mask(LOG_UNIMP, "SMMUv3 S2SL0 = 0x3 has no meaning!\n");
> +        goto bad_ste;
> +    }
> +
> +    /* For AA64, The effective S2PS size is capped to the OAS. */
> +    cfg->s2cfg.eff_ps = oas2bits(MIN(STE_S2PS(ste), SMMU_IDR5_OAS));
> +    /*
> +     * It is ILLEGAL for the address in S2TTB to be outside the range
> +     * described by the effective S2PS value.
> +     */
> +    if (cfg->s2cfg.vttb & ~(MAKE_64BIT_MASK(0, cfg->s2cfg.eff_ps))) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "SMMUv3 S2TTB too large 0x%lx, effective PS %d bits\n",
> +                      cfg->s2cfg.vttb,  cfg->s2cfg.eff_ps);
> +        goto bad_ste;
> +    }
> +
> +    cfg->s2cfg.tsz = STE_S2T0SZ(ste);
> +
> +    if (!s2t0sz_valid(cfg)) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "SMMUv3 bad STE S2T0SZ = %d\n",
> +                      cfg->s2cfg.tsz);
> +        goto bad_ste;
> +    }
> +
> +    if (!s2_pgtable_config_valid(cfg->s2cfg.sl0, cfg->s2cfg.tsz,
> +                                    cfg->s2cfg.granule_sz)) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "SMMUv3 STE stage 2 config not valid!\n");
> +        goto bad_ste;
> +    }
> +
> +    /* Only LE supported(IDR0.TTENDIAN). */
> +    if (STE_S2ENDI(ste)) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "SMMUv3 STE_S2ENDI only supports LE!\n");
> +        goto bad_ste;
> +    }
> +
> +    cfg->s2cfg.affd = STE_S2AFFD(ste);
> +
> +    cfg->s2cfg.record_faults = STE_S2R(ste);
> +    /* As stall is not supported. */
> +    if (STE_S2S(ste)) {
> +        qemu_log_mask(LOG_UNIMP, "SMMUv3 Stall not implemented!\n");
> +        goto bad_ste;
> +    }
> +
> +    /* This is still here as stage 2 has not been fully enabled yet. */
> +    qemu_log_mask(LOG_UNIMP, "SMMUv3 does not support stage 2 yet\n");
> +    goto bad_ste;
> +
> +    return 0;
> +
> +bad_ste:
> +    return -EINVAL;
> +}
> +
>  /* Returns < 0 in case of invalid STE, 0 otherwise */
>  static int decode_ste(SMMUv3State *s, SMMUTransCfg *cfg,
>                        STE *ste, SMMUEventInfo *event)
>  {
>      uint32_t config;
> +    int ret;
>  
>      if (!STE_VALID(ste)) {
>          if (!event->inval_ste_allowed) {
> @@ -354,11 +487,39 @@ static int decode_ste(SMMUv3State *s, SMMUTransCfg *cfg,
>          return 0;
>      }
>  
> -    if (STE_CFG_S2_ENABLED(config)) {
> -        qemu_log_mask(LOG_UNIMP, "SMMUv3 does not support stage 2 yet\n");
> +    /*
> +     * If a stage is enabled in SW while not advertised, throw bad ste
> +     * according to user manual(IHI0070E) "5.2 Stream Table Entry".
> +     */
> +    if (!STAGE1_SUPPORTED(s) && STE_CFG_S1_ENABLED(config)) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "SMMUv3 S1 used but not supported.\n");
> +        goto bad_ste;
> +    }
> +    if (!STAGE2_SUPPORTED(s) && STE_CFG_S2_ENABLED(config)) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "SMMUv3 S2 used but not supported.\n");
>          goto bad_ste;
>      }
>  
> +    if (STAGE2_SUPPORTED(s)) {
> +        /* VMID is considered even if s2 is disabled. */
> +        cfg->s2cfg.vmid = STE_S2VMID(ste);
> +    } else {
> +        /* Default to -1 */
> +        cfg->s2cfg.vmid = -1;
> +    }
> +
> +    if (STE_CFG_S2_ENABLED(config)) {
> +        /*
> +         * Stage-1 OAS defaults to OAS even if not enabled as it would be used
> +         * in input address check for stage-2.
> +         */
> +        cfg->oas = oas2bits(SMMU_IDR5_OAS);
> +        ret = decode_ste_s2_cfg(cfg, ste);
> +        if (ret) {
> +            goto bad_ste;
> +        }
> +    }
> +
>      if (STE_S1CDMAX(ste) != 0) {
>          qemu_log_mask(LOG_UNIMP,
>                        "SMMUv3 does not support multiple context descriptors yet\n");
> @@ -702,7 +863,13 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>      if (cached_entry) {
>          if ((flag & IOMMU_WO) && !(cached_entry->entry.perm & IOMMU_WO)) {
>              status = SMMU_TRANS_ERROR;
> -            if (cfg->record_faults) {
> +            /*
> +             * We know that the TLB only contains either stage-1 or stage-2 as
> +             * nesting is not supported. So it is sufficient to check the
> +             * translation stage to know the TLB stage for now.
> +             */
> +            event.u.f_walk_eabt.s2 = (cfg->stage == 2);
> +            if (PTW_RECORD_FAULT(cfg)) {
>                  event.type = SMMU_EVT_F_PERMISSION;
>                  event.u.f_permission.addr = addr;
>                  event.u.f_permission.rnw = flag & 0x1;
> @@ -728,28 +895,28 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>              event.u.f_walk_eabt.addr2 = ptw_info.addr;
>              break;
>          case SMMU_PTW_ERR_TRANSLATION:
> -            if (cfg->record_faults) {
> +            if (PTW_RECORD_FAULT(cfg)) {
>                  event.type = SMMU_EVT_F_TRANSLATION;
>                  event.u.f_translation.addr = addr;
>                  event.u.f_translation.rnw = flag & 0x1;
>              }
>              break;
>          case SMMU_PTW_ERR_ADDR_SIZE:
> -            if (cfg->record_faults) {
> +            if (PTW_RECORD_FAULT(cfg)) {
>                  event.type = SMMU_EVT_F_ADDR_SIZE;
>                  event.u.f_addr_size.addr = addr;
>                  event.u.f_addr_size.rnw = flag & 0x1;
>              }
>              break;
>          case SMMU_PTW_ERR_ACCESS:
> -            if (cfg->record_faults) {
> +            if (PTW_RECORD_FAULT(cfg)) {
>                  event.type = SMMU_EVT_F_ACCESS;
>                  event.u.f_access.addr = addr;
>                  event.u.f_access.rnw = flag & 0x1;
>              }
>              break;
>          case SMMU_PTW_ERR_PERMISSION:
> -            if (cfg->record_faults) {
> +            if (PTW_RECORD_FAULT(cfg)) {
>                  event.type = SMMU_EVT_F_PERMISSION;
>                  event.u.f_permission.addr = addr;
>                  event.u.f_permission.rnw = flag & 0x1;
> diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
> index 97cea8ea06..4f1405d4e4 100644
> --- a/include/hw/arm/smmu-common.h
> +++ b/include/hw/arm/smmu-common.h
> @@ -29,6 +29,7 @@
>  
>  /* VMSAv8-64 Translation constants and functions */
>  #define VMSA_LEVELS                         4
> +#define VMSA_MAX_S2_CONCAT                  16
>  
>  #define VMSA_STRIDE(gran)                   ((gran) - VMSA_LEVELS + 1)
>  #define VMSA_BIT_LVL(isz, strd, lvl)        ((isz) - (strd) * \
> diff --git a/include/hw/arm/smmuv3.h b/include/hw/arm/smmuv3.h
> index a0c026402e..6031d7d325 100644
> --- a/include/hw/arm/smmuv3.h
> +++ b/include/hw/arm/smmuv3.h
> @@ -83,4 +83,7 @@ struct SMMUv3Class {
>  #define TYPE_ARM_SMMUV3   "arm-smmuv3"
>  OBJECT_DECLARE_TYPE(SMMUv3State, SMMUv3Class, ARM_SMMUV3)
>  
> +#define STAGE1_SUPPORTED(s)      FIELD_EX32(s->idr[0], IDR0, S1P)
> +#define STAGE2_SUPPORTED(s)      FIELD_EX32(s->idr[0], IDR0, S2P)
> +
>  #endif