VT-d: improve RMRR region handling

This patch improves RMRR regions handling as follows:

1) Get rid of duplicated RMRR mapping: different devices may share the
same RMRR regions, when they are assigned to the same guest, it only
need to map the same RMRR region once because RMRR region must be
identity mapped. Add an array of mapped RMRRs to achieve this.

2) Needn't call domain_context_mapping to map the device again in
iommu_prepare_rmrr_dev, and change iommu_prepare_rmrr_dev to
rmrr_identity_mapping which is more suitable.

3) A device may have more than one RMRR regions, remove "break" in
intel_iommu_add_device to let it map all RMRR regions of the device.

Signed-off-by: Weidong Han <Weidong.han@intel.com>

diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index ec6d03ef9bfaefb9afe8624599afbb62f0933fc5..2ec6d5802e15753a99d4173c6db9dd323e8b3054 100644 (file)
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -95,6 +95,7 @@ int iommu_domain_init(struct domain *domain)
 
     spin_lock_init(&hd->mapping_lock);
     INIT_LIST_HEAD(&hd->g2m_ioport_list);
+    INIT_LIST_HEAD(&hd->mapped_rmrrs);
 
     if ( !iommu_enabled )
         return 0;
@@ -187,8 +188,9 @@ static int iommu_populate_page_table(struct domain *d)
 void iommu_domain_destroy(struct domain *d)
 {
     struct hvm_iommu *hd  = domain_hvm_iommu(d);
-    struct list_head *ioport_list, *tmp;
+    struct list_head *ioport_list, *rmrr_list, *tmp;
     struct g2m_ioport *ioport;
+    struct mapped_rmrr *mrmrr;
 
     if ( !iommu_enabled || !hd->platform_ops )
         return;
@@ -211,6 +213,13 @@ void iommu_domain_destroy(struct domain *d)
             list_del(&ioport->list);
             xfree(ioport);
         }
+
+        list_for_each_safe ( rmrr_list, tmp, &hd->mapped_rmrrs )
+        {
+            mrmrr = list_entry(rmrr_list, struct mapped_rmrr, list);
+            list_del(&mrmrr->list);
+            xfree(mrmrr);
+        }
     }
 
     return hd->platform_ops->teardown(d);

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index a6d460a69e8322a4821fe958aa6415ba82ff44d1..5fa2e4cc52b3fb1398b09661f2037fd08154be6a 100644 (file)
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -551,6 +551,8 @@ static void dma_pte_clear_one(struct domain *domain, u64 addr)
     u64 pg_maddr;
     int flush_dev_iotlb;
     int iommu_domid;
+    struct list_head *rmrr_list, *tmp;
+    struct mapped_rmrr *mrmrr;
 
     spin_lock(&hd->mapping_lock);
     /* get last level pte */
@@ -592,6 +594,22 @@ static void dma_pte_clear_one(struct domain *domain, u64 addr)
     }
 
     unmap_vtd_domain_page(page);
+
+    /* if the cleared address is between mapped RMRR region,
+     * remove the mapped RMRR
+     */
+    spin_lock(&pcidevs_lock);
+    list_for_each_safe ( rmrr_list, tmp, &hd->mapped_rmrrs )
+    {
+        mrmrr = list_entry(rmrr_list, struct mapped_rmrr, list);
+        if ( addr >= mrmrr->base && addr <= mrmrr->end )
+        {
+            list_del(&mrmrr->list);
+            xfree(mrmrr);
+            break;
+        }
+    }
+    spin_unlock(&pcidevs_lock);
 }
 
 static void iommu_free_pagetable(u64 pt_maddr, int level)
@@ -1261,21 +1279,6 @@ static int domain_context_mapping(struct domain *domain, u8 bus, u8 devfn)
     u8 secbus;
     struct pci_dev *pdev = pci_get_pdev(bus, devfn);
 
-    if ( pdev == NULL )
-    {
-        /* We can reach here by setup_dom0_rmrr() -> iommu_prepare_rmrr_dev()
-         * -> domain_context_mapping().
-         * In the case a user enables VT-d and disables USB (that usually needs
-         * RMRR) in BIOS, we can't discover the BDF of the USB controller in
-         * setup_dom0_devices(), but the ACPI RMRR structures may still contain
-         * the BDF and at last pci_get_pdev() returns NULL here.
-         */
-        gdprintk(XENLOG_WARNING VTDPREFIX,
-                "domain_context_mapping: can't find bdf = %x:%x.%x\n",
-                 bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
-        return 0;
-    }
-
     drhd = acpi_find_matched_drhd_unit(pdev);
     if ( !drhd )
         return -ENODEV;
@@ -1601,17 +1604,36 @@ static int intel_iommu_unmap_page(struct domain *d, unsigned long gfn)
     return 0;
 }
 
-static int iommu_prepare_rmrr_dev(struct domain *d,
-                                  struct acpi_rmrr_unit *rmrr,
-                                  u8 bus, u8 devfn)
+static int domain_rmrr_mapped(struct domain *d,
+                              struct acpi_rmrr_unit *rmrr)
+{
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+    struct mapped_rmrr *mrmrr;
+
+    list_for_each_entry( mrmrr, &hd->mapped_rmrrs, list )
+    {
+        if ( mrmrr->base == rmrr->base_address &&
+             mrmrr->end == rmrr->end_address )
+            return 1;
+    }
+
+    return 0;
+}
+
+static int rmrr_identity_mapping(struct domain *d,
+                                 struct acpi_rmrr_unit *rmrr)
 {
-    int ret = 0;
     u64 base, end;
     unsigned long base_pfn, end_pfn;
+    struct mapped_rmrr *mrmrr;
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
 
     ASSERT(spin_is_locked(&pcidevs_lock));
     ASSERT(rmrr->base_address < rmrr->end_address);
-    
+
+    if ( domain_rmrr_mapped(d, rmrr) )
+        return 0;
+
     base = rmrr->base_address & PAGE_MASK_4K;
     base_pfn = base >> PAGE_SHIFT_4K;
     end = PAGE_ALIGN_4K(rmrr->end_address);
@@ -1619,13 +1641,19 @@ static int iommu_prepare_rmrr_dev(struct domain *d,
 
     while ( base_pfn < end_pfn )
     {
-        intel_iommu_map_page(d, base_pfn, base_pfn);
+        if ( intel_iommu_map_page(d, base_pfn, base_pfn) )
+            return -1;
         base_pfn++;
     }
 
-    ret = domain_context_mapping(d, bus, devfn);
+    mrmrr = xmalloc(struct mapped_rmrr);
+    if ( !mrmrr )
+        return -ENOMEM;
+    mrmrr->base = rmrr->base_address;
+    mrmrr->end = rmrr->end_address;
+    list_add_tail(&mrmrr->list, &hd->mapped_rmrrs);
 
-    return ret;
+    return 0;
 }
 
 static int intel_iommu_add_device(struct pci_dev *pdev)
@@ -1651,12 +1679,10 @@ static int intel_iommu_add_device(struct pci_dev *pdev)
     {
         if ( PCI_BUS(bdf) == pdev->bus && PCI_DEVFN2(bdf) == pdev->devfn )
         {
-            ret = iommu_prepare_rmrr_dev(pdev->domain, rmrr,
-                                         pdev->bus, pdev->devfn);
+            ret = rmrr_identity_mapping(pdev->domain, rmrr);
             if ( ret )
                 gdprintk(XENLOG_ERR VTDPREFIX,
                          "intel_iommu_add_device: RMRR mapping failed\n");
-            break;
         }
     }
 
@@ -1690,12 +1716,9 @@ static int intel_iommu_remove_device(struct pci_dev *pdev)
 
 static void setup_dom0_devices(struct domain *d)
 {
-    struct hvm_iommu *hd;
     struct pci_dev *pdev;
     int bus, devfn;
 
-    hd = domain_hvm_iommu(d);
-
     spin_lock(&pcidevs_lock);
     for ( bus = 0; bus < 256; bus++ )
     {
@@ -1829,7 +1852,7 @@ static void setup_dom0_rmrr(struct domain *d)
     spin_lock(&pcidevs_lock);
     for_each_rmrr_device ( rmrr, bdf, i )
     {
-        ret = iommu_prepare_rmrr_dev(d, rmrr, PCI_BUS(bdf), PCI_DEVFN2(bdf));
+        ret = rmrr_identity_mapping(d, rmrr);
         if ( ret )
             dprintk(XENLOG_ERR VTDPREFIX,
                      "IOMMU: mapping reserved region failed\n");
@@ -1973,25 +1996,27 @@ static int intel_iommu_assign_device(struct domain *d, u8 bus, u8 devfn)
     if ( ret )
         goto done;
 
+    /* FIXME: Because USB RMRR conflicts with guest bios region,
+     * ignore USB RMRR temporarily.
+     */
+    if ( is_usb_device(bus, devfn) )
+    {
+        ret = 0;
+        goto done;
+    }
+
     /* Setup rmrr identity mapping */
     for_each_rmrr_device( rmrr, bdf, i )
     {
         if ( PCI_BUS(bdf) == bus && PCI_DEVFN2(bdf) == devfn )
         {
-            /* FIXME: Because USB RMRR conflicts with guest bios region,
-             * ignore USB RMRR temporarily.
-             */
-            if ( is_usb_device(bus, devfn) )
-            {
-                ret = 0;
-                goto done;
-            }
-
-            ret = iommu_prepare_rmrr_dev(d, rmrr, bus, devfn);
+            ret = rmrr_identity_mapping(d, rmrr);
             if ( ret )
+            {
                 gdprintk(XENLOG_ERR VTDPREFIX,
                          "IOMMU: mapping reserved region failed\n");
-            goto done; 
+                goto done;
+            }
         }
     }
 

diff --git a/xen/include/xen/hvm/iommu.h b/xen/include/xen/hvm/iommu.h
index 38c52b1e393eada7d5cb723d9c5bc8cd10611961..cc51ca3ea2120f0912fbf9b27de323ea5e3fb81c 100644 (file)
--- a/xen/include/xen/hvm/iommu.h
+++ b/xen/include/xen/hvm/iommu.h
@@ -29,12 +29,19 @@ struct g2m_ioport {
     unsigned int np;
 };
 
+struct mapped_rmrr {
+    struct list_head list;
+    u64 base;
+    u64 end;
+};
+
 struct hvm_iommu {
     u64 pgd_maddr;                 /* io page directory machine address */
     spinlock_t mapping_lock;       /* io page table lock */
     int agaw;     /* adjusted guest address width, 0 is level 2 30-bit */
     struct list_head g2m_ioport_list;  /* guest to machine ioport mapping */
     u64 iommu_bitmap;              /* bitmap of iommu(s) that the domain uses */
+    struct list_head mapped_rmrrs;
 
     /* amd iommu support */
     int domain_id;