Re: [Qemu-arm] [RFC v4 09/16] virtio-iommu: Implement translate

[Bharat Bhushan]

> -----Original Message-----
> From: Eric Auger [mailto:address@hidden
> Sent: Tuesday, September 19, 2017 1:17 PM
> To: address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; jean-
> address@hidden
> Cc: address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden; Bharat Bhushan <address@hidden>;
> address@hidden; address@hidden
> Subject: [RFC v4 09/16] virtio-iommu: Implement translate
> 
> This patch implements the translate callback
> 
> Signed-off-by: Eric Auger <address@hidden>
> ---
>  hw/virtio/trace-events   |  1 +
>  hw/virtio/virtio-iommu.c | 39
> +++++++++++++++++++++++++++++++++++++--
>  2 files changed, 38 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events index
> da298c1..9010fbd 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -45,3 +45,4 @@ virtio_iommu_put_as(uint32_t asid) "Free asid=%d"
>  virtio_iommu_unmap_left_interval(uint64_t low, uint64_t high, uint64_t
> next_low, uint64_t next_high) "Unmap left [0x%"PRIx64",0x%"PRIx64"],
> new interval=[0x%"PRIx64",0x%"PRIx64"]"
>  virtio_iommu_unmap_right_interval(uint64_t low, uint64_t high, uint64_t
> next_low, uint64_t next_high) "Unmap right [0x%"PRIx64",0x%"PRIx64"],
> new interval=[0x%"PRIx64",0x%"PRIx64"]"
>  virtio_iommu_unmap_inc_interval(uint64_t low, uint64_t high) "Unmap inc
> [0x%"PRIx64",0x%"PRIx64"]"
> +virtio_iommu_translate_out(uint64_t virt_addr, uint64_t phys_addr,
> uint32_t sid) "0x%"PRIx64" -> 0x%"PRIx64 " for sid=%d"
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c index
> 6f1a7d1..db46a91 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -496,19 +496,54 @@ static IOMMUTLBEntry
> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>                                              IOMMUAccessFlags flag)  {
>      IOMMUDevice *sdev = container_of(mr, IOMMUDevice, iommu_mr);
> +    VirtIOIOMMU *s = sdev->viommu;
>      uint32_t sid;
> +    viommu_dev *dev;
> +    viommu_mapping *mapping;
> +    viommu_interval interval;
> +
> +    interval.low = addr;
> +    interval.high = addr + 1;
> 
>      IOMMUTLBEntry entry = {
>          .target_as = &address_space_memory,
>          .iova = addr,
>          .translated_addr = addr,
> -        .addr_mask = ~(hwaddr)0,
> -        .perm = IOMMU_NONE,
> +        .addr_mask = (1 << ctz32(s->config.page_size_mask)) - 1,
> +        .perm = flag,
>      };
> 
>      sid = virtio_iommu_get_sid(sdev);
> 
>      trace_virtio_iommu_translate(mr->parent_obj.name, sid, addr, flag);
> +    qemu_mutex_lock(&s->mutex);
> +
> +    dev = g_tree_lookup(s->devices, GUINT_TO_POINTER(sid));
> +    if (!dev) {
> +        /* device cannot be attached to another as */
> +        printf("%s sid=%d is not known!!\n", __func__, sid);
> +        goto unlock;
> +    }
> +
> +    mapping = g_tree_lookup(dev->as->mappings, (gpointer)(&interval));

Should check of !dev->as before accessing this.

Thanks
-Bharat 

> +    if (!mapping) {
> +        printf("%s no mapping for 0x%"PRIx64" for sid=%d\n", __func__,
> +               addr, sid);
> +        goto unlock;
> +    }
> +
> +    if (((flag & IOMMU_RO) && !(mapping->flags &
> VIRTIO_IOMMU_MAP_F_READ)) ||
> +        ((flag & IOMMU_WO) && !(mapping->flags &
> VIRTIO_IOMMU_MAP_F_WRITE))) {
> +        error_report("Permission error on 0x%"PRIx64"(%d): allowed=%d",
> +                     addr, flag, mapping->flags);
> +        entry.perm = IOMMU_NONE;
> +        goto unlock;
> +    }
> +    entry.translated_addr = addr - mapping->virt_addr + mapping-
> >phys_addr,
> +    trace_virtio_iommu_translate_out(addr, entry.translated_addr, sid);
> +
> +unlock:
> +    qemu_mutex_unlock(&s->mutex);
>      return entry;
>  }
> 
> --
> 2.5.5