[Xen-devel] [PATCH 2/5] xen/arm: assign devices to boot domains

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Scan the user provided dtb fragment at boot. For each device node, map
memory to guests, and route interrupts and setup the iommu.

Device memory is only mapped 1:1. It is not possible to assign devices at
locations that conflict with the DomU memory map.

The iommu is setup by passing the to the device to assign on the host
device tree. The path is specified in the device tree fragment as the
"path" string property.

Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
---
 xen/arch/arm/bootfdt.c        |  4 +-
 xen/arch/arm/domain_build.c   | 85 +++++++++++++++++++++++++++++++++++++++++++
 xen/include/xen/device_tree.h |  2 +
 3 files changed, 89 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/bootfdt.c b/xen/arch/arm/bootfdt.c
index 891b4b6..72cb8d6 100644
--- a/xen/arch/arm/bootfdt.c
+++ b/xen/arch/arm/bootfdt.c
@@ -55,8 +55,8 @@ static bool __init device_tree_node_compatible(const void 
*fdt, int node,
     return false;
 }
 
-static void __init device_tree_get_reg(const __be32 **cell, u32 address_cells,
-                                       u32 size_cells, u64 *start, u64 *size)
+void __init device_tree_get_reg(const __be32 **cell, u32 address_cells,
+                                u32 size_cells, u64 *start, u64 *size)
 {
     *start = dt_next_cell(address_cells, cell);
     *size = dt_next_cell(size_cells, cell);
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index cc6b464..d48f77e 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2094,6 +2094,88 @@ static int __init construct_domain(struct domain *d, 
struct kernel_info *kinfo)
     return 0;
 }
 
+static int __init scan_pt_node(const void *pfdt,
+                               int nodeoff, const char *name, int depth,
+                               u32 address_cells, u32 size_cells,
+                               void *data)
+{
+    int rc;
+    struct dt_device_node *node;
+    int len, i;
+    const struct fdt_property *prop;
+    struct kernel_info *kinfo = data;
+    struct domain *d = kinfo->d;
+    const __be32 *cell;
+
+    if ( depth > 2 )
+        return 0;
+
+    prop = fdt_get_property_namelen(pfdt, nodeoff, "reg", strlen("reg"), &len);
+    if ( prop != NULL )
+    {
+        paddr_t start, size;
+        cell = (const __be32 *)prop->data;
+        len = fdt32_to_cpu(prop->len) /
+              ((address_cells + size_cells) * sizeof (u32));
+
+        for ( i = 0; i < len; i++ )
+        {
+            device_tree_get_reg(&cell, address_cells, size_cells, &start, 
&size);
+
+            rc = guest_physmap_add_entry(d, _gfn(start >> PAGE_SHIFT),
+                                         _mfn(start >> PAGE_SHIFT),
+                                         get_order_from_bytes(size),
+                                         p2m_mmio_direct_dev);
+            if ( rc < 0 )
+            {
+                dprintk(XENLOG_ERR, "Failed to map %"PRIpaddr" to the 
guest\n", start);
+                return -EFAULT;
+            }
+        }
+    }
+
+    prop = fdt_get_property_namelen(pfdt, nodeoff, "path", strlen("path"), 
&len);
+    if ( prop != NULL ) {
+        node = dt_find_node_by_path((char *)&prop->data[0]);
+        if ( node != NULL )
+            rc = iommu_assign_dt_device(d, node);
+        else
+            dprintk(XENLOG_ERR, "Couldn't find node %s in host_dt!\n",
+                    (char *)&prop->data[0]);
+    }
+
+    prop = fdt_get_property_namelen(pfdt, nodeoff, "interrupts", 
strlen("interrupts"), &len);
+    if ( prop != NULL )
+    {
+        int pt_irq;
+        u32 *u = (u32*) &prop->data[0];
+
+        pt_irq = fdt32_to_cpu(*(u + 1)) + 32;
+
+        vgic_reserve_virq(d, pt_irq);
+        rc = route_irq_to_guest(d, pt_irq, pt_irq, "routed IRQ");
+        if ( rc < 0 )
+            return rc;
+    }
+    return 0;
+}
+
+static int __init domain_addign_devices(struct domain *d,
+                                        struct kernel_info *kinfo)
+{
+    void *pfdt;
+
+    pfdt = ioremap_cache(kinfo->dtb_bootmodule->start,
+            kinfo->dtb_bootmodule->size);
+    if ( pfdt == NULL )
+        return -EFAULT;
+
+    device_tree_for_each_node(pfdt, scan_pt_node, kinfo);
+
+    iounmap(pfdt);
+    return 0;
+}
+
 static int __init construct_domU(struct domain *d,
                                  const struct dt_device_node *node)
 {
@@ -2140,6 +2222,9 @@ static int __init construct_domU(struct domain *d,
     if ( kinfo.vpl011 )
         rc = domain_vpl011_init(d, NULL);
 
+    if ( kinfo.dtb_bootmodule )
+        rc = domain_addign_devices(d, &kinfo);
+
     return rc;
 }
 
diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index 7408a6c..356a422 100644
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -161,6 +161,8 @@ extern const void *device_tree_flattened;
 int device_tree_for_each_node(const void *fdt,
                                      device_tree_node_func func,
                                      void *data);
+void device_tree_get_reg(const __be32 **cell, u32 address_cells,
+                         u32 size_cells, u64 *start, u64 *size);
 
 /**
  * dt_unflatten_host_device_tree - Unflatten the host device tree
-- 
1.9.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel