ARM: ITS: Deny hardware domain access to ITS

This patch extends the gicv3_iomem_deny_access functionality by adding
support for ITS region as well. Add function gicv3_its_deny_access.

Signed-off-by: Manish Jaggi <mjaggi@cavium.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Julien Grall <julien.grall@arm.com>

xen/arch/arm/gic-v3-its.c

@@ -21,6 +21,7 @@
 #include <xen/acpi.h>
 #include <xen/lib.h>
 #include <xen/delay.h>
+#include <xen/iocap.h>
 #include <xen/libfdt/libfdt.h>
 #include <xen/mm.h>
 #include <xen/rbtree.h>
@@ -905,6 +906,27 @@ struct pending_irq *gicv3_assign_guest_event(struct domain *d,
     return pirq;
 }
 
+int gicv3_its_deny_access(const struct domain *d)
+{
+    int rc = 0;
+    unsigned long mfn, nr;
+    const struct host_its *its_data;
+
+    list_for_each_entry( its_data, &host_its_list, entry )
+    {
+        mfn = paddr_to_pfn(its_data->addr);
+        nr = PFN_UP(its_data->size);
+        rc = iomem_deny_access(d, mfn, mfn + nr);
+        if ( rc )
+        {
+            printk("iomem_deny_access failed for %lx:%lx \r\n", mfn, nr);
+            break;
+        }
+    }
+
+    return rc;
+}
+
 /*
  * Create the respective guest DT nodes from a list of host ITSes.
  * This copies the reg property, so the guest sees the ITS at the same address

xen/arch/arm/gic-v3.c

@@ -1308,6 +1308,10 @@ static int gicv3_iomem_deny_access(const struct domain *d)
     if ( rc )
         return rc;
 
+    rc = gicv3_its_deny_access(d);
+    if ( rc )
+        return rc;
+
     for ( i = 0; i < gicv3.rdist_count; i++ )
     {
         mfn = gicv3.rdist_regions[i].base >> PAGE_SHIFT;

xen/include/asm-arm/gic_v3_its.h

@@ -139,6 +139,10 @@ void gicv3_its_dt_init(const struct dt_device_node *node);
 #ifdef CONFIG_ACPI
 void gicv3_its_acpi_init(void);
 #endif
+
+/* Deny iomem access for its */
+int gicv3_its_deny_access(const struct domain *d);
+
 bool gicv3_its_host_has_its(void);
 
 unsigned int vgic_v3_its_count(const struct domain *d);
@@ -206,6 +210,11 @@ static inline void gicv3_its_acpi_init(void)
 }
 #endif
 
+static inline int gicv3_its_deny_access(const struct domain *d)
+{
+    return 0;
+}
+
 static inline bool gicv3_its_host_has_its(void)
 {
     return false;