[PATCH v5 4/9] iommu/vt-d: Setup pasid entries for iova over first level

Lu Baolu
2019-12-24T07:46:22Z

Intel VT-d in scalable mode supports two types of page tables for
IOVA translation: first level and second level. The IOMMU driver
can choose one from both for IOVA translation according to the use
case. This sets up the pasid entry if a domain is selected to use
the first-level page table for iova translation.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 57 +++++++++++++++++++++++++++++++++----
include/linux/intel-iommu.h | 16 +++++++----
2 files changed, 62 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 35f65628202c..071cbc172ce8 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -571,6 +571,11 @@ static inline int domain_type_is_si(struct dmar_domain *domain)
return domain->flags & DOMAIN_FLAG_STATIC_IDENTITY;
}

+static inline bool domain_use_first_level(struct dmar_domain *domain)
+{
+ return domain->flags & DOMAIN_FLAG_USE_FIRST_LEVEL;
+}
+
static inline int domain_pfn_supported(struct dmar_domain *domain,
unsigned long pfn)
{
@@ -932,6 +937,8 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,

domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
+ if (domain_use_first_level(domain))
+ pteval |= DMA_FL_PTE_XD;
if (cmpxchg64(&pte->val, 0ULL, pteval))
/* Someone else set it while we were thinking; use theirs. */
free_pgtable_page(tmp_page);
@@ -2281,17 +2288,20 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
unsigned long sg_res = 0;
unsigned int largepage_lvl = 0;
unsigned long lvl_pages = 0;
+ u64 attr;

BUG_ON(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1));

if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
return -EINVAL;

- prot &= DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP;
+ attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP);
+ if (domain_use_first_level(domain))
+ attr |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD;

if (!sg) {
sg_res = nr_pages;
- pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | prot;
+ pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr;
}

while (nr_pages > 0) {
@@ -2303,7 +2313,7 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
sg_res = aligned_nrpages(sg->offset, sg->length);
sg->dma_address = ((dma_addr_t)iov_pfn << VTD_PAGE_SHIFT) + pgoff;
sg->dma_length = sg->length;
- pteval = (sg_phys(sg) - pgoff) | prot;
+ pteval = (sg_phys(sg) - pgoff) | attr;
phys_pfn = pteval >> VTD_PAGE_SHIFT;
}

@@ -2515,6 +2525,36 @@ dmar_search_domain_by_dev_info(int segment, int bus, int devfn)
return NULL;
}

+static int domain_setup_first_level(struct intel_iommu *iommu,
+ struct dmar_domain *domain,
+ struct device *dev,
+ int pasid)
+{
+ int flags = PASID_FLAG_SUPERVISOR_MODE;
+ struct dma_pte *pgd = domain->pgd;
+ int agaw, level;
+
+ /*
+ * Skip top levels of page tables for iommu which has
+ * less agaw than default. Unnecessary for PT mode.
+ */
+ for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
+ pgd = phys_to_virt(dma_pte_addr(pgd));
+ if (!dma_pte_present(pgd))
+ return -ENOMEM;
+ }
+
+ level = agaw_to_level(agaw);
+ if (level != 4 && level != 5)
+ return -EINVAL;
+
+ flags |= (level == 5) ? PASID_FLAG_FL5LP : 0;
+
+ return intel_pasid_setup_first_level(iommu, dev, (pgd_t *)pgd, pasid,
+ domain->iommu_did[iommu->seq_id],
+ flags);
+}
+
static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
int bus, int devfn,
struct device *dev,
@@ -2614,6 +2654,9 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
if (hw_pass_through && domain_type_is_si(domain))
ret = intel_pasid_setup_pass_through(iommu, domain,
dev, PASID_RID2PASID);
+ else if (domain_use_first_level(domain))
+ ret = domain_setup_first_level(iommu, domain, dev,
+ PASID_RID2PASID);
else
ret = intel_pasid_setup_second_level(iommu, domain,
dev, PASID_RID2PASID);
@@ -5374,8 +5417,12 @@ static int aux_domain_add_dev(struct dmar_domain *domain,
goto attach_failed;

/* Setup the PASID entry for mediated devices: */
- ret = intel_pasid_setup_second_level(iommu, domain, dev,
- domain->default_pasid);
+ if (domain_use_first_level(domain))
+ ret = domain_setup_first_level(iommu, domain, dev,
+ domain->default_pasid);
+ else
+ ret = intel_pasid_setup_second_level(iommu, domain, dev,
+ domain->default_pasid);
if (ret)
goto table_failed;
spin_unlock(&iommu->lock);
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index aaece25c055f..454c69712131 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -34,10 +34,13 @@
#define VTD_STRIDE_SHIFT (9)
#define VTD_STRIDE_MASK (((u64)-1) << VTD_STRIDE_SHIFT)

-#define DMA_PTE_READ (1)
-#define DMA_PTE_WRITE (2)
-#define DMA_PTE_LARGE_PAGE (1 << 7)
-#define DMA_PTE_SNP (1 << 11)
+#define DMA_PTE_READ BIT_ULL(0)
+#define DMA_PTE_WRITE BIT_ULL(1)
+#define DMA_PTE_LARGE_PAGE BIT_ULL(7)
+#define DMA_PTE_SNP BIT_ULL(11)
+
+#define DMA_FL_PTE_PRESENT BIT_ULL(0)
+#define DMA_FL_PTE_XD BIT_ULL(63)

#define CONTEXT_TT_MULTI_LEVEL 0
#define CONTEXT_TT_DEV_IOTLB 1
@@ -610,10 +613,11 @@ static inline void dma_clear_pte(struct dma_pte *pte)
static inline u64 dma_pte_addr(struct dma_pte *pte)
{
#ifdef CONFIG_64BIT
- return pte->val & VTD_PAGE_MASK;
+ return pte->val & VTD_PAGE_MASK & (~DMA_FL_PTE_XD);
#else
/* Must have a full atomic 64-bit read */
- return __cmpxchg64(&pte->val, 0ULL, 0ULL) & VTD_PAGE_MASK;
+ return __cmpxchg64(&pte->val, 0ULL, 0ULL) &
+ VTD_PAGE_MASK & (~DMA_FL_PTE_XD);
#endif