[PATCH 11/13] check agaw is sufficient for mapped memory

[Han, Weidong]

virtual machine domain may own multiple devices from different iommus, and agaw 
may be different across iommus. Because one domain used one VT-d page table, 
it's necessary to check if agaw is sufficient for mapped memory.

Signed-off-by: Weidong Han <[EMAIL PROTECTED]>
---
 drivers/pci/intel-iommu.c     |   63 +++++++++++++++++++++++++++++++++++++++++
 include/linux/dma_remapping.h |    1 +
 2 files changed, 64 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 0db77e2..a8c2e58 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2552,6 +2552,25 @@ static void vm_domain_remove_all_dev_info(struct 
dmar_domain *domain)
 /* domain id for virtual machine, it won't be set in context */
 static unsigned long vm_domid;
 
+static int vm_domain_min_agaw(struct dmar_domain *domain)
+{
+       struct dmar_drhd_unit *drhd;
+       struct intel_iommu *iommu;
+       int min_agaw = domain->agaw;
+
+       for_each_drhd_unit(drhd) {
+               if (drhd->ignored)
+                       continue;
+               iommu = drhd->iommu;
+
+               if (test_bit(iommu->seq_id, &domain->iommu_bmp))
+                       if (min_agaw > iommu->agaw)
+                               min_agaw = iommu->agaw;
+       }
+
+       return min_agaw;
+}
+
 static struct dmar_domain *iommu_alloc_vm_domain(void)
 {
        struct dmar_domain *domain;
@@ -2563,6 +2582,7 @@ static struct dmar_domain *iommu_alloc_vm_domain(void)
        domain->id = vm_domid++;
        domain->iommu_count = 0;
        domain->iommu_coherency = 0;
+       domain->max_addr = 0;
        memset(&domain->iommu_bmp, 0, sizeof(unsigned long));
        domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;
 
@@ -2675,6 +2695,9 @@ EXPORT_SYMBOL_GPL(intel_iommu_free_domain);
 int intel_iommu_attach_device(struct dmar_domain *domain,
                              struct pci_dev *pdev)
 {
+       struct intel_iommu *iommu;
+       int addr_width;
+       u64 end;
        int ret;
 
        /* normally pdev is not mapped */
@@ -2690,6 +2713,21 @@ int intel_iommu_attach_device(struct dmar_domain *domain,
                }
        }
 
+       iommu = device_find_matched_iommu(pdev->bus->number, pdev->devfn);
+       if (!iommu)
+               return -ENODEV;
+
+       /* check if this iommu agaw is sufficient for max mapped address */
+       addr_width = agaw_to_width(iommu->agaw);
+       end = DOMAIN_MAX_ADDR(addr_width);
+       end = end & VTD_PAGE_MASK;
+       if (end < domain->max_addr) {
+               printk(KERN_ERR "%s: iommu agaw (%d) is not "
+                      "sufficient for the mapped address (%llx)\n",
+                      __func__, iommu->agaw, domain->max_addr);
+               return -EFAULT;
+       }
+
        ret = domain_context_mapping(domain, pdev);
        if (ret)
                return ret;
@@ -2709,7 +2747,29 @@ EXPORT_SYMBOL_GPL(intel_iommu_detach_device);
 int intel_iommu_map_address(struct dmar_domain *domain, dma_addr_t iova,
                            u64 hpa, size_t size, int prot)
 {
+       u64 max_addr;
+       int addr_width;
        int ret;
+
+       max_addr = (iova & VTD_PAGE_MASK) + VTD_PAGE_ALIGN(size);
+       if (domain->max_addr < max_addr) {
+               int min_agaw;
+               u64 end;
+
+               /* check if minimum agaw is sufficient for mapped address */
+               min_agaw = vm_domain_min_agaw(domain);
+               addr_width = agaw_to_width(min_agaw);
+               end = DOMAIN_MAX_ADDR(addr_width);
+               end = end & VTD_PAGE_MASK;
+               if (end < max_addr) {
+                       printk(KERN_ERR "%s: iommu agaw (%d) is not "
+                              "sufficient for the mapped address (%llx)\n",
+                              __func__, min_agaw, max_addr);
+                       return -EFAULT;
+               }
+               domain->max_addr = max_addr;
+       }
+
        ret = domain_page_mapping(domain, iova, hpa, size, prot);
        return ret;
 }
@@ -2724,6 +2784,9 @@ void intel_iommu_unmap_address(struct dmar_domain *domain,
        base = iova & VTD_PAGE_MASK;
        size = VTD_PAGE_ALIGN(size);
        dma_pte_clear_range(domain, base, base + size);
+
+       if (domain->max_addr == base + size)
+               domain->max_addr = base;
 }
 EXPORT_SYMBOL_GPL(intel_iommu_unmap_address);
 
diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h
index f6925c5..880fa17 100644
--- a/include/linux/dma_remapping.h
+++ b/include/linux/dma_remapping.h
@@ -187,6 +187,7 @@ struct dmar_domain {
 
        int             iommu_coherency;/* iommu access is coherent or not */
        int             iommu_count;    /* reference count of iommu */
+       u64             max_addr;       /* maximum mapped address */
 };
 
 /* PCI domain-device relationship */
-- 
1.5.1

0011-check-agaw-is-sufficient-for-mapped-memory.patch
Description: 0011-check-agaw-is-sufficient-for-mapped-memory.patch