[PATCH] arm/acpi: don't expose the ACPI IORT SMMUv3 entry to dom0

[Rahul Singh <rahul.singh@xxxxxxx>]

Xen should control the SMMUv3 devices therefore, don't expose the
SMMUv3 devices to dom0. Deny iomem access to SMMUv3 address space for
dom0 and also make ACPI IORT SMMUv3 node type to 0xff.

Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
---
 xen/arch/arm/acpi/domain_build.c | 40 ++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/xen/arch/arm/acpi/domain_build.c b/xen/arch/arm/acpi/domain_build.c
index bbdc90f92c..ec0b5b261f 100644
--- a/xen/arch/arm/acpi/domain_build.c
+++ b/xen/arch/arm/acpi/domain_build.c
@@ -14,6 +14,7 @@
 #include <xen/acpi.h>
 #include <xen/event.h>
 #include <xen/iocap.h>
+#include <xen/sizes.h>
 #include <xen/device_tree.h>
 #include <xen/libfdt/libfdt.h>
 #include <acpi/actables.h>
@@ -30,6 +31,7 @@ static int __init acpi_iomem_deny_access(struct domain *d)
 {
     acpi_status status;
     struct acpi_table_spcr *spcr = NULL;
+    struct acpi_table_iort *iort;
     unsigned long mfn;
     int rc;
 
@@ -55,6 +57,44 @@ static int __init acpi_iomem_deny_access(struct domain *d)
         printk("Failed to get SPCR table, Xen console may be unavailable\n");
     }
 
+    status = acpi_get_table(ACPI_SIG_IORT, 0,
+                            (struct acpi_table_header **)&iort);
+
+    if ( ACPI_SUCCESS(status) )
+    {
+        int i;
+        struct acpi_iort_node *node, *end;
+        node = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->node_offset);
+        end = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->header.length);
+
+        for ( i = 0; i < iort->node_count; i++ )
+        {
+            if ( node >= end )
+                break;
+
+            switch ( node->type )
+            {
+                case ACPI_IORT_NODE_SMMU_V3:
+                {
+                    struct acpi_iort_smmu_v3 *smmu;
+                    smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
+                    mfn = paddr_to_pfn(smmu->base_address);
+                    rc = iomem_deny_access(d, mfn, mfn + PFN_UP(SZ_128K));
+                    if ( rc )
+                        printk("iomem_deny_access failed for SMMUv3\n");
+                    node->type = 0xff;
+                    break;
+                }
+            }
+            node = ACPI_ADD_PTR(struct acpi_iort_node, node, node->length);
+        }
+    }
+    else
+    {
+        printk("Failed to get IORT table\n");
+        return -EINVAL;
+    }
+
     /* Deny MMIO access for GIC regions */
     return gic_iomem_deny_access(d);
 }
-- 
2.25.1