[Xen-devel] [v8][PATCH 16/17] xen/vtd: group assigned device with RMRR

[Tiejun Chen <tiejun.chen@xxxxxxxxx>]

Sometimes different devices may share RMRR range so in this
case we shouldn't assign these devices into different VMs
since they may have potential leakage even damage between VMs.

So we need to group all devices as RMRR range to make sure they
are just assigned into the same VM.

Here we introduce two field, gid and domid, in struct,
acpi_rmrr_unit:
 gid: indicate which group this device owns. "0" is invalid so
      just start from "1".
 domid: indicate which domain this device owns currently. Firstly
        the hardware domain should own it.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
---
 xen/drivers/passthrough/vtd/dmar.c  | 28 ++++++++++++++-
 xen/drivers/passthrough/vtd/dmar.h  |  2 ++
 xen/drivers/passthrough/vtd/iommu.c | 68 +++++++++++++++++++++++++++++++++----
 3 files changed, 91 insertions(+), 7 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/dmar.c 
b/xen/drivers/passthrough/vtd/dmar.c
index c5bc8d6..8d3406f 100644
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -572,10 +572,11 @@ acpi_parse_one_rmrr(struct acpi_dmar_header *header)
 {
     struct acpi_dmar_reserved_memory *rmrr =
         container_of(header, struct acpi_dmar_reserved_memory, header);
-    struct acpi_rmrr_unit *rmrru;
+    struct acpi_rmrr_unit *rmrru, *cur_rmrr;
     void *dev_scope_start, *dev_scope_end;
     u64 base_addr = rmrr->base_address, end_addr = rmrr->end_address;
     int ret;
+    static unsigned int group_id = 0;
 
     if ( (ret = acpi_dmar_check_length(header, sizeof(*rmrr))) != 0 )
         return ret;
@@ -611,6 +612,8 @@ acpi_parse_one_rmrr(struct acpi_dmar_header *header)
     rmrru->base_address = base_addr;
     rmrru->end_address = end_addr;
     rmrru->segment = rmrr->segment;
+    /* "0" is an invalid group id. */
+    rmrru->gid = 0;
 
     dev_scope_start = (void *)(rmrr + 1);
     dev_scope_end   = ((void *)rmrr) + header->length;
@@ -682,7 +685,30 @@ acpi_parse_one_rmrr(struct acpi_dmar_header *header)
                     "So please set pci_rdmforce to reserve these ranges"
                     " if you need such a device in hotplug case.\n");
 
+            list_for_each_entry(cur_rmrr, &acpi_rmrr_units, list)
+            {
+                /*
+                 * Any same or overlap range mean they should be
+                 * at same group.
+                 */
+                if ( ((base_addr >= cur_rmrr->base_address) &&
+                     (end_addr <= cur_rmrr->end_address)) ||
+                     ((base_addr <= cur_rmrr->base_address) &&
+                     (end_addr >= cur_rmrr->end_address)) )
+                {
+                    rmrru->gid = cur_rmrr->gid;
+                    continue;
+                }
+            }
+
             acpi_register_rmrr_unit(rmrru);
+
+            /* Allocate group id from gid:1. */
+            if ( !rmrru->gid )
+            {
+                group_id++;
+                rmrru->gid = group_id;
+            }
         }
     }
 
diff --git a/xen/drivers/passthrough/vtd/dmar.h 
b/xen/drivers/passthrough/vtd/dmar.h
index af1feef..a57c0d4 100644
--- a/xen/drivers/passthrough/vtd/dmar.h
+++ b/xen/drivers/passthrough/vtd/dmar.h
@@ -76,6 +76,8 @@ struct acpi_rmrr_unit {
     u64    end_address;
     u16    segment;
     u8     allow_all:1;
+    int    gid;
+    domid_t    domid;
 };
 
 struct acpi_atsr_unit {
diff --git a/xen/drivers/passthrough/vtd/iommu.c 
b/xen/drivers/passthrough/vtd/iommu.c
index a54c6eb..ba40209 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1882,9 +1882,9 @@ static int rmrr_identity_mapping(struct domain *d, bool_t 
map,
 
 static int intel_iommu_add_device(u8 devfn, struct pci_dev *pdev)
 {
-    struct acpi_rmrr_unit *rmrr;
-    u16 bdf;
-    int ret, i;
+    struct acpi_rmrr_unit *rmrr, *g_rmrr;
+    u16 bdf, g_bdf;
+    int ret, i, j;
 
     ASSERT(spin_is_locked(&pcidevs_lock));
 
@@ -1905,6 +1905,32 @@ static int intel_iommu_add_device(u8 devfn, struct 
pci_dev *pdev)
              PCI_BUS(bdf) == pdev->bus &&
              PCI_DEVFN2(bdf) == devfn )
         {
+            if ( rmrr->domid == hardware_domain->domain_id )
+            {
+                for_each_rmrr_device ( g_rmrr, g_bdf, j )
+                {
+                    if ( g_rmrr->gid == rmrr->gid )
+                    {
+                        if ( g_rmrr->domid == hardware_domain->domain_id )
+                            g_rmrr->domid = pdev->domain->domain_id;
+                        else if ( g_rmrr->domid != pdev->domain->domain_id )
+                        {
+                            rmrr->domid = g_rmrr->domid;
+                            continue;
+                        }
+                    }
+                }
+            }
+
+            if ( rmrr->domid != pdev->domain->domain_id )
+            {
+                domain_context_unmap(pdev->domain, devfn, pdev);
+                dprintk(XENLOG_ERR VTDPREFIX, "d%d: this is a group device 
owned by d%d\n",
+                        pdev->domain->domain_id, rmrr->domid);
+                rmrr->domid = 0;
+                return -EINVAL;
+            }
+
             ret = rmrr_identity_mapping(pdev->domain, 1, rmrr);
             if ( ret )
                 dprintk(XENLOG_ERR VTDPREFIX, "d%d: RMRR mapping failed\n",
@@ -1946,6 +1972,8 @@ static int intel_iommu_remove_device(u8 devfn, struct 
pci_dev *pdev)
              PCI_DEVFN2(bdf) != devfn )
             continue;
 
+        /* Just release to hardware domain. */
+        rmrr->domid = hardware_domain->domain_id;
         rmrr_identity_mapping(pdev->domain, 0, rmrr);
     }
 
@@ -2104,6 +2132,8 @@ static void __hwdom_init setup_hwdom_rmrr(struct domain 
*d)
     spin_lock(&pcidevs_lock);
     for_each_rmrr_device ( rmrr, bdf, i )
     {
+        /* hwdom should own all devices at first. */
+        rmrr->domid = d->domain_id;
         ret = rmrr_identity_mapping(d, 1, rmrr);
         if ( ret )
             dprintk(XENLOG_ERR VTDPREFIX,
@@ -2273,9 +2303,9 @@ static int reassign_device_ownership(
 static int intel_iommu_assign_device(
     struct domain *d, u8 devfn, struct pci_dev *pdev)
 {
-    struct acpi_rmrr_unit *rmrr;
-    int ret = 0, i;
-    u16 bdf, seg;
+    struct acpi_rmrr_unit *rmrr, *g_rmrr;
+    int ret = 0, i, j;
+    u16 bdf, seg, g_bdf;
     u8 bus;
 
     if ( list_empty(&acpi_drhd_units) )
@@ -2300,6 +2330,32 @@ static int intel_iommu_assign_device(
              PCI_BUS(bdf) == bus &&
              PCI_DEVFN2(bdf) == devfn )
         {
+            if ( rmrr->domid == hardware_domain->domain_id )
+            {
+                for_each_rmrr_device ( g_rmrr, g_bdf, j )
+                {
+                    if ( g_rmrr->gid == rmrr->gid )
+                    {
+                        if ( g_rmrr->domid == hardware_domain->domain_id )
+                            g_rmrr->domid = pdev->domain->domain_id;
+                        else if ( g_rmrr->domid != pdev->domain->domain_id )
+                        {
+                            rmrr->domid = g_rmrr->domid;
+                            continue;
+                        }
+                    }
+                }
+            }
+
+            if ( rmrr->domid != pdev->domain->domain_id )
+            {
+                domain_context_unmap(pdev->domain, devfn, pdev);
+                dprintk(XENLOG_ERR VTDPREFIX, "d%d: this is a group device 
owned by d%d\n",
+                        pdev->domain->domain_id, rmrr->domid);
+                rmrr->domid = 0;
+                return -EINVAL;
+            }
+
             ret = rmrr_identity_mapping(d, 1, rmrr);
             if ( ret )
             {
-- 
1.9.1


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