Re: [v2][PATCH 1/1] xen:vtd: missing RMRR mapping while share EPT

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

On 2014/7/24 16:57, Andrew Cooper wrote:
> On 24/07/14 09:50, Tiejun Chen wrote:
>> intel_iommu_map_page() does nothing if VT-d shares EPT page table.
>> So rmrr_identity_mapping() never create RMRR mapping but in some
>> cases like some GFX drivers it still need to access RMRR.
>>
>> Here we will create those RMRR mappings even in shared EPT case.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>> ---
>>   xen/drivers/passthrough/vtd/iommu.c | 18 ++++++++++++++++--
>>   1 file changed, 16 insertions(+), 2 deletions(-)
>>
>> v2:
>>
>> * Fix coding style.
>> * Still need to abide intel_iommu_map_page(), so we should do nothing
>>    if dom0 and iommu supports pass thru.
>>
>> diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
>> index 042b882..aca79db 100644
>> --- a/xen/drivers/passthrough/vtd/iommu.c
>> +++ b/xen/drivers/passthrough/vtd/iommu.c
>> @@ -41,6 +41,7 @@
>>   #include "extern.h"
>>   #include "vtd.h"
>>   #include "../ats.h"
>> +#include "../../../arch/x86/mm/mm-locks.h"
>
> <asm/mm/mm-locks.h>

iommu.c:38:29: fatal error: asm/mm/mm-locks.h: No such file or directory
  #include <asm/mm/mm-locks.h>
                              ^
compilation terminated.

Tiejun

>
> ~Andrew
>
>>
>>   struct mapped_rmrr {
>>       struct list_head list;
>> @@ -1842,6 +1843,7 @@ static int rmrr_identity_mapping(struct domain *d,
>>       unsigned long base_pfn, end_pfn;
>>       struct mapped_rmrr *mrmrr;
>>       struct hvm_iommu *hd = domain_hvm_iommu(d);
>> +    struct p2m_domain *p2m = p2m_get_hostp2m(d);
>>
>>       ASSERT(spin_is_locked(&pcidevs_lock));
>>       ASSERT(rmrr->base_address < rmrr->end_address);
>> @@ -1867,8 +1869,20 @@ static int rmrr_identity_mapping(struct domain *d,
>>
>>       while ( base_pfn < end_pfn )
>>       {
>> -        if ( intel_iommu_map_page(d, base_pfn, base_pfn,
>> -                                  IOMMUF_readable|IOMMUF_writable) )
>> +        if ( iommu_use_hap_pt(d) && (!iommu_passthrough ||
>> +                                     !is_hardware_domain(d)) )
>> +        {
>> +            p2m_lock(p2m);
>> +            if ( p2m_set_entry(p2m, base_pfn, _mfn(base_pfn), PAGE_ORDER_4K,
>> +                               p2m_mmio_direct, p2m_access_rw) )
>> +            {
>> +                p2m_unlock(p2m);
>> +                return -1;
>> +            }
>> +            p2m_unlock(p2m);
>> +        }
>> +        else if ( intel_iommu_map_page(d, base_pfn, base_pfn,
>> +                                       IOMMUF_readable|IOMMUF_writable) )
>>               return -1;
>>           base_pfn++;
>>       }
>
>
>