Re: [Qemu-arm] [PATCH for-4.2 v10 13/15] virtio_iommu: Handle reserved regions in translation process

[Michael S. Tsirkin]

On Tue, Jul 30, 2019 at 07:21:35PM +0200, Eric Auger wrote:
> When translating an address we need to check if it belongs to
> a reserved virtual address range. If it does, there are 2 cases:
> 
> - it belongs to a RESERVED region: the guest should neither use
>   this address in a MAP not instruct the end-point to DMA on
>   them. We report an error
> 
> - It belongs to an MSI region: we bypass the translation.
> 
> Signed-off-by: Eric Auger <address@hidden>

something wrong with the subject here.

> ---
> 
> v9 -> v10:
> - in case of MSI region, we immediatly return
> ---
>  hw/virtio/virtio-iommu.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index 8e54a17227..20d92b7ab0 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -711,6 +711,7 @@ static IOMMUTLBEntry 
> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>      viommu_interval interval;
>      bool bypass_allowed;
>      bool read_fault, write_fault;
> +    struct virtio_iommu_probe_resv_mem *reg;
>  
>      interval.low = addr;
>      interval.high = addr + 1;
> @@ -743,6 +744,21 @@ static IOMMUTLBEntry 
> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>          goto unlock;
>      }
>  
> +    reg = g_tree_lookup(ep->reserved_regions, (gpointer)(&interval));
> +    if (reg) {
> +        switch (reg->subtype) {
> +        case VIRTIO_IOMMU_RESV_MEM_T_MSI:
> +            entry.perm = flag;
> +            return entry;
> +        case VIRTIO_IOMMU_RESV_MEM_T_RESERVED:
> +        default:
> +            virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_MAPPING,
> +                                      0, sid, addr);
> +            break;
> +        }
> +        goto unlock;
> +    }
> +
>      if (!ep->domain) {
>          if (!bypass_allowed) {
>              qemu_log_mask(LOG_GUEST_ERROR,
> -- 
> 2.20.1