>>> On 23.08.18 at 11:47, <paul.durr...@citrix.com> wrote:
> This patch adds a new method to the VT-d IOMMU implementation to find the
> MFN currently mapped by the specified BFN along with a wrapper function in
> generic IOMMU code to call the implementation if it exists.
For this to go in, I think the AMD side of it wants to also be implemented.
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -305,6 +305,17 @@ int iommu_unmap_page(struct domain *d, bfn_t bfn)
> return rc;
> }
>
> +int iommu_lookup_page(struct domain *d, bfn_t bfn, mfn_t *mfn,
> + unsigned int *flags)
> +{
> + const struct domain_iommu *hd = dom_iommu(d);
> +
> + if ( !iommu_enabled || !hd->platform_ops )
> + return -EOPNOTSUPP;
> +
> + return hd->platform_ops->lookup_page(d, bfn, mfn, flags);
> +}
Shouldn't this be restricted to PV guests? HVM ones aren't supposed
to know about MFNs.
> +static int intel_iommu_lookup_page(struct domain *d, bfn_t bfn, mfn_t *mfn,
> + unsigned int *flags)
> +{
> + struct domain_iommu *hd = dom_iommu(d);
> + struct dma_pte *page = NULL, *pte = NULL, val;
Pointless initializers. I also question the usefulness of "pte":
> + u64 pg_maddr;
> +
> + spin_lock(&hd->arch.mapping_lock);
> +
> + pg_maddr = addr_to_dma_page_maddr(d, bfn_to_baddr(bfn), 0);
> + if ( pg_maddr == 0 )
> + {
> + spin_unlock(&hd->arch.mapping_lock);
> + return -ENOMEM;
> + }
> +
> + page = map_vtd_domain_page(pg_maddr);
> + pte = page + (bfn_x(bfn) & LEVEL_MASK);
> + val = *pte;
val = page[bfn_x(bfn) & LEVEL_MASK];
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
