[Xen-devel,v5,17/22] arm/gic: Add a new callback to deny Dom0 access to GIC regions

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 02db5f2..186f944 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -22,6 +22,7 @@ 
 #include <xen/init.h>
 #include <xen/mm.h>
 #include <xen/irq.h>
+#include <xen/iocap.h>
 #include <xen/sched.h>
 #include <xen/errno.h>
 #include <xen/softirq.h>
@@ -714,6 +715,31 @@  static u32 gicv2_make_hwdom_madt(const struct domain *d, u32 offset)
     return table_len;
 }
 
+static int gicv2_iomem_deny_access(const struct domain *d)
+{
+    int rc;
+    unsigned long gfn, nr;
+
+    gfn = dbase >> PAGE_SHIFT;
+    rc = iomem_deny_access(d, gfn, gfn + 1);
+    if ( rc )
+        return rc;
+
+    gfn = hbase >> PAGE_SHIFT;
+    rc = iomem_deny_access(d, gfn, gfn + 1);
+    if ( rc )
+        return rc;
+
+    gfn = cbase >> PAGE_SHIFT;
+    nr = DIV_ROUND_UP(csize, PAGE_SIZE);
+    rc = iomem_deny_access(d, gfn, gfn + nr);
+    if ( rc )
+        return rc;
+
+    gfn = vbase >> PAGE_SHIFT;
+    return iomem_deny_access(d, gfn, gfn + nr);
+}
+
 static int __init
 gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
                         const unsigned long end)
@@ -809,6 +835,10 @@  static u32 gicv2_make_hwdom_madt(const struct domain *d, u32 offset)
 {
     return 0;
 }
+static int gicv2_iomem_deny_access(const struct domain *d)
+{
+    return 0;
+}
 #endif
 
 static int __init gicv2_init(void)
@@ -902,6 +932,7 @@  const static struct gic_hw_operations gicv2_ops = {
     .read_apr            = gicv2_read_apr,
     .make_hwdom_dt_node  = gicv2_make_hwdom_dt_node,
     .make_hwdom_madt     = gicv2_make_hwdom_madt,
+    .iomem_deny_access   = gicv2_iomem_deny_access,
 };
 
 /* Set up the GIC */
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index d9fce4b..67797f2 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -27,6 +27,7 @@ 
 #include <xen/cpu.h>
 #include <xen/mm.h>
 #include <xen/irq.h>
+#include <xen/iocap.h>
 #include <xen/sched.h>
 #include <xen/errno.h>
 #include <xen/delay.h>
@@ -1278,6 +1279,44 @@  static u32 gicv3_make_hwdom_madt(const struct domain *d, u32 offset)
     return table_len;
 }
 
+static int gicv3_iomem_deny_access(const struct domain *d)
+{
+    int rc, i;
+    unsigned long gfn, nr;
+
+    gfn = dbase >> PAGE_SHIFT;
+    rc = iomem_deny_access(d, gfn, gfn + 1);
+    if ( rc )
+        return rc;
+
+    for ( i = 0; i < gicv3.rdist_count; i++ )
+    {
+        gfn = gicv3.rdist_regions[i].base >> PAGE_SHIFT;
+        nr = DIV_ROUND_UP(gicv3.rdist_regions[i].size, PAGE_SIZE);
+        rc = iomem_deny_access(d, gfn, gfn + nr);
+        if ( rc )
+            return rc;
+    }
+
+    if ( cbase != INVALID_PADDR )
+    {
+        gfn = cbase >> PAGE_SHIFT;
+        nr = DIV_ROUND_UP(csize, PAGE_SIZE);
+        rc = iomem_deny_access(d, gfn, gfn + nr);
+        if ( rc )
+            return rc;
+    }
+
+    if ( vbase != INVALID_PADDR )
+    {
+        gfn = vbase >> PAGE_SHIFT;
+        nr = DIV_ROUND_UP(csize, PAGE_SIZE);
+        return iomem_deny_access(d, gfn, gfn + nr);
+    }
+
+    return 0;
+}
+
 static int __init
 gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
                         const unsigned long end)
@@ -1426,6 +1465,10 @@  static u32 gicv3_make_hwdom_madt(const struct domain *d, u32 offset)
 {
     return 0;
 }
+static int gicv3_iomem_deny_access(const struct domain *d)
+{
+    return 0;
+}
 #endif
 
 /* Set up the GIC */
@@ -1521,6 +1564,7 @@  static const struct gic_hw_operations gicv3_ops = {
     .secondary_init      = gicv3_secondary_cpu_init,
     .make_hwdom_dt_node  = gicv3_make_hwdom_dt_node,
     .make_hwdom_madt     = gicv3_make_hwdom_madt,
+    .iomem_deny_access   = gicv3_iomem_deny_access,
 };
 
 static int __init gicv3_dt_preinit(struct dt_device_node *node, const void *data)
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 6d32432..65022ee 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -744,6 +744,11 @@  u32 gic_make_hwdom_madt(const struct domain *d, u32 offset)
     return gic_hw_ops->make_hwdom_madt(d, offset);
 }
 
+int gic_iomem_deny_access(const struct domain *d)
+{
+    return gic_hw_ops->iomem_deny_access(d);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index 4cf003d..932fc02 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -360,6 +360,8 @@  struct gic_hw_operations {
                               const struct dt_device_node *gic, void *fdt);
     /* Create MADT table for the hardware domain */
     u32 (*make_hwdom_madt)(const struct domain *d, u32 offset);
+    /* Deny access to GIC regions */
+    int (*iomem_deny_access)(const struct domain *d);
 };
 
 void register_gic_ops(const struct gic_hw_operations *ops);
@@ -367,6 +369,7 @@  int gic_make_hwdom_dt_node(const struct domain *d,
                            const struct dt_device_node *gic,
                            void *fdt);
 u32 gic_make_hwdom_madt(const struct domain *d, u32 offset);
+int gic_iomem_deny_access(const struct domain *d);
 
 #endif /* __ASSEMBLY__ */
 #endif