[RFC PATCH 15/21] xen/arm: vsmmuv3: Emulated SMMUv3 device tree node for dom0less

[Rahul Singh <rahul.singh@xxxxxxx>]

XEN will create an Emulated SMMUv3 device tree node in the device tree
to enable the dom0less domains to discover the virtual SMMUv3 during
boot. Emulated SMMUv3 device tree node will only be created when cmdline
option vsmmuv3 is enabled.

Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
---
 xen/arch/arm/domain_build.c           | 52 +++++++++++++++++++++++++++
 xen/include/public/device_tree_defs.h |  1 +
 2 files changed, 53 insertions(+)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index b82121beb5..29f00b18ec 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2322,6 +2322,49 @@ static int make_hwdom_viommu_node(const struct 
kernel_info *kinfo)
 }
 #endif
 
+#ifdef CONFIG_VIRTUAL_ARM_SMMU_V3
+static int __init make_vsmmuv3_node(const struct kernel_info *kinfo)
+{
+    int res;
+    char buf[24];
+    __be32 reg[GUEST_ROOT_ADDRESS_CELLS + GUEST_ROOT_SIZE_CELLS];
+    __be32 *cells;
+    void *fdt = kinfo->fdt;
+
+    snprintf(buf, sizeof(buf), "iommu@%llx", GUEST_VSMMUV3_BASE);
+
+    res = fdt_begin_node(fdt, buf);
+    if ( res )
+        return res;
+
+    res = fdt_property_string(fdt, "compatible", "arm,smmu-v3");
+    if ( res )
+        return res;
+
+    /* Create reg property */
+    cells = &reg[0];
+    dt_child_set_range(&cells, GUEST_ROOT_ADDRESS_CELLS, GUEST_ROOT_SIZE_CELLS,
+                       GUEST_VSMMUV3_BASE, GUEST_VSMMUV3_SIZE);
+    res = fdt_property(fdt, "reg", reg,
+                       (GUEST_ROOT_ADDRESS_CELLS +
+                       GUEST_ROOT_SIZE_CELLS) * sizeof(*reg));
+    if ( res )
+        return res;
+
+    res = fdt_property_cell(fdt, "phandle", GUEST_PHANDLE_VSMMUV3);
+    if ( res )
+        return res;
+
+    res = fdt_property_cell(fdt, "#iommu-cells", 1);
+    if ( res )
+        return res;
+
+    res = fdt_end_node(fdt);
+
+    return res;
+}
+#endif
+
 int __init map_irq_to_domain(struct domain *d, unsigned int irq,
                              bool need_mapping, const char *devname)
 {
@@ -3395,6 +3438,15 @@ static int __init prepare_dtb_domU(struct domain *d, 
struct kernel_info *kinfo)
             goto err;
     }
 
+#ifdef CONFIG_VIRTUAL_ARM_SMMU_V3
+    if ( is_viommu_enabled() )
+    {
+        ret = make_vsmmuv3_node(kinfo);
+        if ( ret )
+            goto err;
+    }
+#endif
+
     ret = fdt_end_node(kinfo->fdt);
     if ( ret < 0 )
         goto err;
diff --git a/xen/include/public/device_tree_defs.h 
b/xen/include/public/device_tree_defs.h
index 9e80d0499d..7846a0425c 100644
--- a/xen/include/public/device_tree_defs.h
+++ b/xen/include/public/device_tree_defs.h
@@ -14,6 +14,7 @@
  */
 #define GUEST_PHANDLE_GIC (65000)
 #define GUEST_PHANDLE_IOMMU (GUEST_PHANDLE_GIC + 1)
+#define GUEST_PHANDLE_VSMMUV3 (GUEST_PHANDLE_IOMMU + 1)
 
 #define GUEST_ROOT_ADDRESS_CELLS 2
 #define GUEST_ROOT_SIZE_CELLS 2
-- 
2.25.1