[Xen-devel] [PATCH v3 18/25] xen/arm: generate a simple device tree for domUs

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Introduce functions to generate a basic domU device tree, similar to the
existing functions in tools/libxl/libxl_arm.c.

Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
---
Changes in v3:
- remove CONFIG_ACPI for make_chosen_node
- remove make_hypervisor_node until all Xen related functionalities
  (evtchns, grant table, etc.) work correctly

Changes in v2:
- move prepare_dtb rename to previous patch
- use switch for the gic version
- use arm,gic-400 instead of arm,cortex-a15-gic
- add @unit-address in the gic node name
- add comment on DOMU_DTB_SIZE
---
 xen/arch/arm/domain_build.c | 211 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 209 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index dfa74e4..167a56e 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1057,7 +1057,6 @@ static int __init make_timer_node(const struct domain *d, 
void *fdt,
     return res;
 }
 
-#ifdef CONFIG_ACPI
 /*
  * This function is used as part of the device tree generation for Dom0
  * on ACPI systems, and DomUs started directly from Xen based on device
@@ -1103,7 +1102,6 @@ static int __init make_chosen_node(const struct 
kernel_info *kinfo)
 
     return res;
 }
-#endif
 
 static int __init map_irq_to_domain(struct domain *d, unsigned int irq,
                                     bool need_mapping, const char *devname)
@@ -1496,6 +1494,211 @@ static int __init handle_node(struct domain *d, struct 
kernel_info *kinfo,
     return res;
 }
 
+static int __init make_gic_domU_node(const struct domain *d, void *fdt, int 
addrcells, int sizecells)
+{
+    int res = 0;
+    int reg_size = addrcells + sizecells;
+    int nr_cells = reg_size * 2;
+    __be32 reg[nr_cells];
+    __be32 *cells;
+
+    switch ( gic_hw_version() )
+    {
+    case GIC_V3:
+        res = fdt_begin_node(fdt, 
"interrupt-controller@"__stringify(GUEST_GICV3_GICD_BASE));
+        break;
+    case GIC_V2:
+        res = fdt_begin_node(fdt, 
"interrupt-controller@"__stringify(GUEST_GICD_BASE));
+        break;
+    default:
+        panic("Unsupported GIC version");
+    }
+
+    if ( res )
+        return res;
+
+    res = fdt_property_cell(fdt, "#address-cells", 0);
+    if ( res )
+        return res;
+
+    res = fdt_property_cell(fdt, "#interrupt-cells", 3);
+    if ( res )
+        return res;
+
+    res = fdt_property(fdt, "interrupt-controller", NULL, 0);
+    if ( res )
+        return res;
+
+    switch ( gic_hw_version() )
+    {
+    case GIC_V3:
+    {
+        const uint64_t gicd_base = GUEST_GICV3_GICD_BASE;
+        const uint64_t gicd_size = GUEST_GICV3_GICD_SIZE;
+        const uint64_t gicr0_base = GUEST_GICV3_GICR0_BASE;
+        const uint64_t gicr0_size = GUEST_GICV3_GICR0_SIZE;
+
+        res = fdt_property_string(fdt, "compatible", "arm,gic-v3");
+        if ( res )
+            return res;
+
+        cells = &reg[0];
+        dt_child_set_range(&cells, addrcells, sizecells, gicd_base, gicd_size);
+        dt_child_set_range(&cells, addrcells, sizecells, gicr0_base, 
gicr0_size);
+        res = fdt_property(fdt, "reg", reg, sizeof(reg));
+        break;
+    }
+    case GIC_V2:
+    {
+        const uint64_t gicd_base = GUEST_GICD_BASE;
+        const uint64_t gicd_size = GUEST_GICD_SIZE;
+        const uint64_t gicc_base = GUEST_GICC_BASE;
+        const uint64_t gicc_size = GUEST_GICC_SIZE;
+
+        res = fdt_property_string(fdt, "compatible", "arm,gic-400");
+        if ( res )
+            return res;
+
+        cells = &reg[0];
+        dt_child_set_range(&cells, addrcells, sizecells, gicd_base, gicd_size);
+        dt_child_set_range(&cells, addrcells, sizecells, gicc_base, gicc_size);
+        break;
+    }
+    default:
+        break;
+    }
+
+    res = fdt_property(fdt, "reg", reg, sizeof(reg));
+    if (res)
+        return res;
+
+    res = fdt_property_cell(fdt, "linux,phandle", GUEST_PHANDLE_GIC);
+    if (res)
+        return res;
+
+    res = fdt_property_cell(fdt, "phandle", GUEST_PHANDLE_GIC);
+    if (res)
+        return res;
+
+    res = fdt_end_node(fdt);
+
+    return res;
+}
+
+static int __init make_timer_domU_node(const struct domain *d, void *fdt)
+{
+    int res;
+    gic_interrupt_t intrs[3];
+
+    res = fdt_begin_node(fdt, "timer");
+    if ( res )
+        return res;
+
+    if (!is_64bit_domain(d))
+    {
+        res = fdt_property_string(fdt, "compatible", "arm,armv7-timer");
+        if ( res )
+            return res;
+    } else {
+        res = fdt_property_string(fdt, "compatible", "arm,armv8-timer");
+        if ( res )
+            return res;
+    }
+
+    set_interrupt_ppi(intrs[0], GUEST_TIMER_PHYS_S_PPI, 0xf, 
DT_IRQ_TYPE_LEVEL_LOW);
+    set_interrupt_ppi(intrs[1], GUEST_TIMER_PHYS_NS_PPI, 0xf, 
DT_IRQ_TYPE_LEVEL_LOW);
+    set_interrupt_ppi(intrs[2], GUEST_TIMER_VIRT_PPI, 0xf, 
DT_IRQ_TYPE_LEVEL_LOW);
+
+    res = fdt_property(fdt, "interrupts", intrs, sizeof (intrs[0]) * 3);
+    if ( res )
+        return res;
+
+    res = fdt_property_cell(fdt, "interrupt-parent",
+                            GUEST_PHANDLE_GIC);
+    if (res)
+        return res;
+
+    res = fdt_end_node(fdt);
+    return res;
+}
+
+/*
+ * The max size for DT is 2MB. However, the generated DT is small, 4KB
+ * are enough for now, but we might have to increase it in the feature.
+ */
+#define DOMU_DTB_SIZE 4096
+static int __init prepare_dtb_domU(struct domain *d, struct kernel_info *kinfo)
+{
+    int addrcells, sizecells;
+    int ret;
+
+    addrcells = dt_child_n_addr_cells(dt_host);
+    sizecells = dt_child_n_size_cells(dt_host);
+
+    kinfo->fdt = xmalloc_bytes(DOMU_DTB_SIZE);
+    if ( kinfo->fdt == NULL )
+        return -ENOMEM;
+
+    ret = fdt_create(kinfo->fdt, DOMU_DTB_SIZE);
+    if ( ret < 0 )
+        goto err;
+
+    ret = fdt_finish_reservemap(kinfo->fdt);
+    if ( ret < 0 )
+        goto err;
+
+    ret = fdt_begin_node(kinfo->fdt, "/");
+    if ( ret < 0 )
+        goto err;
+
+    ret = fdt_property_cell(kinfo->fdt, "#address-cells", addrcells);
+    if ( ret )
+        goto err;
+
+    ret = fdt_property_cell(kinfo->fdt, "#size-cells", sizecells);
+    if ( ret )
+        goto err;
+
+    ret = make_chosen_node(kinfo);
+    if ( ret )
+        goto err;
+
+    ret = make_psci_node(kinfo->fdt, NULL);
+    if ( ret )
+        goto err;
+
+    ret = make_cpus_node(d, kinfo->fdt, NULL);
+    if ( ret )
+        goto err;
+
+    ret = make_memory_node(d, kinfo->fdt, addrcells, sizecells, kinfo);
+    if ( ret )
+        goto err;
+
+    ret = make_gic_domU_node(d, kinfo->fdt, addrcells, sizecells);
+    if ( ret )
+        goto err;
+
+    ret = make_timer_domU_node(d, kinfo->fdt);
+    if ( ret )
+        goto err;
+
+    ret = fdt_end_node(kinfo->fdt);
+    if ( ret < 0 )
+        goto err;
+
+    ret = fdt_finish(kinfo->fdt);
+    if ( ret < 0 )
+        goto err;
+
+    return 0;
+
+  err:
+    printk("Device tree generation failed (%d).\n", ret);
+    xfree(kinfo->fdt);
+    return -EINVAL;
+}
+
 static int __init prepare_dtb_hwdom(struct domain *d, struct kernel_info 
*kinfo)
 {
     const p2m_type_t default_p2mt = p2m_mmio_direct_c;
@@ -2366,6 +2569,10 @@ static int __init construct_domU(struct domain *d, 
struct dt_device_node *node)
 #endif
     allocate_memory(d, &kinfo);
 
+    rc = prepare_dtb_domU(d, &kinfo);
+    if ( rc < 0 )
+        return rc;
+
     return __construct_domain(d, &kinfo);
 }
 
-- 
1.9.1


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