Re: [PATCH v4 15/19] hw/arm/smmuv3: Support nested SMMUs in smmuv3_notify_iova()

[Jean-Philippe Brucker]

On Mon, Jul 01, 2024 at 11:02:37AM +0000, Mostafa Saleh wrote:
> IOMMUTLBEvent only understands IOVA, for stage-1 or stage-2
> SMMU instances we consider the input address as the IOVA, but when
> nesting is used, we can't mix stage-1 and stage-2 addresses, so for
> nesting only stage-1 is considered the IOVA and would be notified.
> 
> Signed-off-by: Mostafa Saleh <smostafa@google.com>
> ---
>  hw/arm/smmuv3.c     | 28 +++++++++++++++++++---------
>  hw/arm/trace-events |  2 +-
>  2 files changed, 20 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index e9007af3cd..36eb6f514a 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -1064,17 +1064,17 @@ epilogue:
>   * @iova: iova
>   * @tg: translation granule (if communicated through range invalidation)
>   * @num_pages: number of @granule sized pages (if tg != 0), otherwise 1
> + * @stage: Which stage(1 or 2) is used
>   */
>  static void smmuv3_notify_iova(IOMMUMemoryRegion *mr,
>                                 IOMMUNotifier *n,
>                                 int asid, int vmid,
>                                 dma_addr_t iova, uint8_t tg,
> -                               uint64_t num_pages)
> +                               uint64_t num_pages, int stage)
>  {
>      SMMUDevice *sdev = container_of(mr, SMMUDevice, iommu);
>      IOMMUTLBEvent event;
>      uint8_t granule;
> -    SMMUv3State *s = sdev->smmu;
>  
>      if (!tg) {

Should the stage check be outside of the TG test?  I think CMD_TLBI_S2_IPA
with TG != 0 and nesting enabled would still go through.

Thanks,
Jean

>          SMMUEventInfo eventinfo = {.inval_ste_allowed = true};
> @@ -1093,14 +1093,24 @@ static void smmuv3_notify_iova(IOMMUMemoryRegion *mr,
>              return;
>          }
>  
> -        if (STAGE1_SUPPORTED(s)) {
> +        /*
> +         * stage is passed from TLB invalidation commands which can be either
> +         * stage-1 or stage-2.
> +         * However, IOMMUTLBEvent only understands IOVA, for stage-1 or 
> stage-2
> +         * SMMU instances we consider the input address as the IOVA, but when
> +         * nesting is used, we can't mix stage-1 and stage-2 addresses, so 
> for
> +         * nesting only stage-1 is considered the IOVA and would be notified.
> +         */
> +        if (stage == SMMU_STAGE_1) {
>              tt = select_tt(cfg, iova);
>              if (!tt) {
>                  return;
>              }
>              granule = tt->granule_sz;
> -        } else {
> +        } else if ((stage == SMMU_STAGE_2) && (cfg->stage != SMMU_NESTED)) {
>              granule = cfg->s2cfg.granule_sz;
> +        } else {
> +            return;
>          }
>  
>      } else {
> @@ -1119,7 +1129,7 @@ static void smmuv3_notify_iova(IOMMUMemoryRegion *mr,
>  /* invalidate an asid/vmid/iova range tuple in all mr's */
>  static void smmuv3_inv_notifiers_iova(SMMUState *s, int asid, int vmid,
>                                        dma_addr_t iova, uint8_t tg,
> -                                      uint64_t num_pages)
> +                                      uint64_t num_pages, int stage)
>  {
>      SMMUDevice *sdev;
>  
> @@ -1128,10 +1138,10 @@ static void smmuv3_inv_notifiers_iova(SMMUState *s, 
> int asid, int vmid,
>          IOMMUNotifier *n;
>  
>          trace_smmuv3_inv_notifiers_iova(mr->parent_obj.name, asid, vmid,
> -                                        iova, tg, num_pages);
> +                                        iova, tg, num_pages, stage);
>  
>          IOMMU_NOTIFIER_FOREACH(n, mr) {
> -            smmuv3_notify_iova(mr, n, asid, vmid, iova, tg, num_pages);
> +            smmuv3_notify_iova(mr, n, asid, vmid, iova, tg, num_pages, 
> stage);
>          }
>      }
>  }
> @@ -1162,7 +1172,7 @@ static void smmuv3_range_inval(SMMUState *s, Cmd *cmd, 
> SMMUStage stage)
>  
>      if (!tg) {
>          trace_smmuv3_range_inval(vmid, asid, addr, tg, 1, ttl, leaf, stage);
> -        smmuv3_inv_notifiers_iova(s, asid, vmid, addr, tg, 1);
> +        smmuv3_inv_notifiers_iova(s, asid, vmid, addr, tg, 1, stage);
>          if (stage == SMMU_STAGE_1) {
>              smmu_iotlb_inv_iova(s, asid, vmid, addr, tg, 1, ttl);
>          } else {
> @@ -1185,7 +1195,7 @@ static void smmuv3_range_inval(SMMUState *s, Cmd *cmd, 
> SMMUStage stage)
>          num_pages = (mask + 1) >> granule;
>          trace_smmuv3_range_inval(vmid, asid, addr, tg, num_pages,
>                                   ttl, leaf, stage);
> -        smmuv3_inv_notifiers_iova(s, asid, vmid, addr, tg, num_pages);
> +        smmuv3_inv_notifiers_iova(s, asid, vmid, addr, tg, num_pages, stage);
>          if (stage == SMMU_STAGE_1) {
>              smmu_iotlb_inv_iova(s, asid, vmid, addr, tg, num_pages, ttl);
>          } else {
> diff --git a/hw/arm/trace-events b/hw/arm/trace-events
> index 593cc571da..be6c8f720b 100644
> --- a/hw/arm/trace-events
> +++ b/hw/arm/trace-events
> @@ -55,7 +55,7 @@ smmuv3_cmdq_tlbi_s12_vmid(int vmid) "vmid=%d"
>  smmuv3_config_cache_inv(uint32_t sid) "Config cache INV for sid=0x%x"
>  smmuv3_notify_flag_add(const char *iommu) "ADD SMMUNotifier node for iommu 
> mr=%s"
>  smmuv3_notify_flag_del(const char *iommu) "DEL SMMUNotifier node for iommu 
> mr=%s"
> -smmuv3_inv_notifiers_iova(const char *name, int asid, int vmid, uint64_t 
> iova, uint8_t tg, uint64_t num_pages) "iommu mr=%s asid=%d vmid=%d 
> iova=0x%"PRIx64" tg=%d num_pages=0x%"PRIx64
> +smmuv3_inv_notifiers_iova(const char *name, int asid, int vmid, uint64_t 
> iova, uint8_t tg, uint64_t num_pages, int stage) "iommu mr=%s asid=%d vmid=%d 
> iova=0x%"PRIx64" tg=%d num_pages=0x%"PRIx64" stage=%d"
>  
>  # strongarm.c
>  strongarm_uart_update_parameters(const char *label, int speed, char parity, 
> int data_bits, int stop_bits) "%s speed=%d parity=%c data=%d stop=%d"
> -- 
> 2.45.2.803.g4e1b14247a-goog
>