Re: [Qemu-devel] [PATCH qemu v18 3/5] vfio: Add host side DMA window capabilities

[David Gibson <david@gibson.dropbear.id.au>]

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On Tue, Jun 21, 2016 at 11:14:03AM +1000, Alexey Kardashevskiy wrote:
> There are going to be multiple IOMMUs per a container. This moves
> the single host IOMMU parameter set to a list of VFIOHostDMAWindow.
> 
> This should cause no behavioral change and will be used later by
> the SPAPR TCE IOMMU v2 which will also add a vfio_host_win_del() helper.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

Looks ok to me.  Again, Alex, your tree or mine?

One minor point..
[snip]
> @@ -878,17 +908,14 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as)
>           * existing Type1 IOMMUs generally support any IOVA we're
>           * going to actually try in practice.
>           */
> -        container->min_iova = 0;
> -        container->max_iova = (hwaddr)-1;
> -
> -        /* Assume just 4K IOVA page size */
> -        container->iova_pgsizes = 0x1000;
>          info.argsz = sizeof(info);
>          ret = ioctl(fd, VFIO_IOMMU_GET_INFO, &info);
>          /* Ignore errors */
> -        if ((ret == 0) && (info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> -            container->iova_pgsizes = info.iova_pgsizes;
> +        if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> +            /* Assume 4k IOVA page size */
> +            info.iova_pgsizes = 4096;
>          }
> +        vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);

I don't think it needs to hold this patch up, but at some point we
should work out the real range covered by the x86 IOMMU tables and put
that in here.  I'm pretty sure it won't actually be 2^64-1.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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