lkml.org 
[lkml]   [2019]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [RFC PATCH 3/4] iommu/vt-d: Map/unmap domain with mmmap/mmunmap
From
Date
Hi,

On 9/25/19 1:00 PM, Tian, Kevin wrote:
>> From: Lu Baolu [mailto:baolu.lu@linux.intel.com]
>> Sent: Monday, September 23, 2019 8:25 PM
>>
>> If a dmar domain has DOMAIN_FLAG_FIRST_LEVEL_TRANS bit set
>> in its flags, IOMMU will use the first level page table for
>> translation. Hence, we need to map or unmap addresses in the
>> first level page table.
>>
>> Cc: Ashok Raj <ashok.raj@intel.com>
>> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
>> Cc: Kevin Tian <kevin.tian@intel.com>
>> Cc: Liu Yi L <yi.l.liu@intel.com>
>> Cc: Yi Sun <yi.y.sun@linux.intel.com>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>> drivers/iommu/intel-iommu.c | 94 ++++++++++++++++++++++++++++++++-
>> ----
>> 1 file changed, 82 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>> index 9cfe8098d993..103480016010 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -168,6 +168,11 @@ static inline unsigned long virt_to_dma_pfn(void
>> *p)
>> return page_to_dma_pfn(virt_to_page(p));
>> }
>>
>> +static inline unsigned long dma_pfn_to_addr(unsigned long pfn)
>> +{
>> + return pfn << VTD_PAGE_SHIFT;
>> +}
>> +
>> /* global iommu list, set NULL for ignored DMAR units */
>> static struct intel_iommu **g_iommus;
>>
>> @@ -307,6 +312,9 @@ static int hw_pass_through = 1;
>> */
>> #define DOMAIN_FLAG_LOSE_CHILDREN BIT(1)
>>
>> +/* Domain uses first level translation for DMA remapping. */
>> +#define DOMAIN_FLAG_FIRST_LEVEL_TRANS BIT(2)
>> +
>> #define for_each_domain_iommu(idx, domain) \
>> for (idx = 0; idx < g_num_of_iommus; idx++) \
>> if (domain->iommu_refcnt[idx])
>> @@ -552,6 +560,11 @@ static inline int domain_type_is_si(struct
>> dmar_domain *domain)
>> return domain->flags & DOMAIN_FLAG_STATIC_IDENTITY;
>> }
>>
>> +static inline int domain_type_is_flt(struct dmar_domain *domain)
>> +{
>> + return domain->flags & DOMAIN_FLAG_FIRST_LEVEL_TRANS;
>> +}
>> +
>> static inline int domain_pfn_supported(struct dmar_domain *domain,
>> unsigned long pfn)
>> {
>> @@ -1147,8 +1160,15 @@ static struct page *domain_unmap(struct
>> dmar_domain *domain,
>> BUG_ON(start_pfn > last_pfn);
>>
>> /* we don't need lock here; nobody else touches the iova range */
>> - freelist = dma_pte_clear_level(domain, agaw_to_level(domain-
>>> agaw),
>> - domain->pgd, 0, start_pfn, last_pfn,
>> NULL);
>> + if (domain_type_is_flt(domain))
>> + freelist = intel_mmunmap_range(domain,
>> + dma_pfn_to_addr(start_pfn),
>> + dma_pfn_to_addr(last_pfn + 1));
>> + else
>> + freelist = dma_pte_clear_level(domain,
>> + agaw_to_level(domain->agaw),
>> + domain->pgd, 0, start_pfn,
>> + last_pfn, NULL);
>
> what about providing an unified interface at the caller side, then having
> the level differentiated within the interface?

Good point! I ever thought about adding some ops in struct dmar_domain,
something like:

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index ed11ef594378..1dd184f76bfb 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -489,7 +489,14 @@ struct dmar_domain {
struct list_head auxd; /* link to device's auxiliary
list */
struct iova_domain iovad; /* iova's that belong to this
domain */

+ /* per domain page table and manipulation ops */
struct dma_pte *pgd; /* virtual address */
+ int (*map)(struct dmar_domain *domain,
+ unsigned long addr, unsigned long end,
+ phys_addr_t phys_addr, int dma_prot);
+ struct page *(*unmap)(struct dmar_domain *domain,
+ unsigned long addr, unsigned long end);
+
int gaw; /* max guest address width */

/* adjusted guest address width, 0 is level 2 30-bit */
So that this code could be simply like this:

freelist = domain->unmap(...);

Best regards,
Baolu

\
 
 \ /
  Last update: 2019-09-25 09:09    [W:0.057 / U:0.608 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site