Re: [PATCH for 4.6] VT-d: Create IOMMU mappings for RMRR regions if shared EPT is not being used

["Chen, Tiejun" <tiejun.chen@intel.com>]

This kind of issue is already gone.

https://www.mail-archive.com/xen-devel@lists.xen.org/msg32464.html

Thanks
Tiejun

On 8/26/2015 11:49 PM, Malcolm Crossley wrote:
> Add RMRR 1:1 IOMMU mappings to IOMMU page tables if EPT page table are not being
> shared with the IOMMU.
>
> This is a regression in behaviour versus Xen 4.5.
>
> Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com>
> ---
>   xen/drivers/passthrough/vtd/iommu.c | 23 ++++++++++++++++++++---
>   1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
> index 836aed5..89de741 100644
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -1839,8 +1839,16 @@ static int rmrr_identity_mapping(struct domain *d, bool_t map,
>
>               while ( base_pfn < end_pfn )
>               {
> -                if ( clear_identity_p2m_entry(d, base_pfn) )
> -                    ret = -ENXIO;
> +                if ( iommu_use_hap_pt(d) )
> +                {
> +                    if ( clear_identity_p2m_entry(d, base_pfn) )
> +                            ret = -ENXIO;
> +                }
> +                else
> +                {
> +                    if ( intel_iommu_unmap_page(d, base_pfn) )
> +                        ret = -ENXIO;
> +                }
>                   base_pfn++;
>               }
>
> @@ -1855,7 +1863,16 @@ static int rmrr_identity_mapping(struct domain *d, bool_t map,
>
>       while ( base_pfn < end_pfn )
>       {
> -        int err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw, flag);
> +        int err;
> +        if ( iommu_use_hap_pt(d) )
> +        {
> +            err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw, flag);
> +        }
> +        else
> +        {
> +            err = intel_iommu_map_page(d, base_pfn, base_pfn,
> +                                       IOMMUF_readable|IOMMUF_writable);
> +        }
>
>           if ( err )
>               return err;
>