Re: [Qemu-devel] [PATCH v12 7/9] hw/arm/sysbus-fdt: enable vfio-calxeda-xgmac dynamic instantiation

[Vikram Sethi]

Hi Eric,

On 03/19/15 12:16, Eric Auger wrote:

This patch allows the instantiation of the vfio-calxeda-xgmac device
from the QEMU command line (-device vfio-calxeda-xgmac,host="<device>").

A specialized device tree node is created for the guest, containing
compat, dma-coherent, reg and interrupts properties.

Signed-off-by: Eric Auger <address@hidden>

---
v10 -> v11:
- add dma-coherent property to calxeda midway xgmac node (fix)
- use qemu_fdt_setprop to add reg property instead of
  qemu_fdt_setprop_sized_cells_from_array
- commit message rewording

v8 -> v9:
- properly free resources in case of errors in
  add_calxeda_midway_xgmac_fdt_node

v7 -> v8:
- move the add_fdt_node_functions array declaration between the device
  specific code and the generic code to avoid forward declarations of
  decice specific functions
- rename add_basic_vfio_fdt_node into
  add_calxeda_midway_xgmac_fdt_node

v6 -> v7:
- compat string re-formatting removed since compat string is not exposed
  anymore as a user option
- VFIO IRQ kick-off removed from sysbus-fdt and moved to VFIO platform
  device
---
 hw/arm/sysbus-fdt.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
index 3038b94..6e465b2 100644
--- a/hw/arm/sysbus-fdt.c
+++ b/hw/arm/sysbus-fdt.c
@@ -26,6 +26,8 @@
 #include "sysemu/device_tree.h"
 #include "hw/platform-bus.h"
 #include "sysemu/sysemu.h"
+#include "hw/vfio/vfio-platform.h"
+#include "hw/vfio/vfio-calxeda-xgmac.h"
 
 /*
  * internal struct that contains the information to create dynamic
@@ -53,11 +55,81 @@ typedef struct NodeCreationPair {
     int (*add_fdt_node_fn)(SysBusDevice *sbdev, void *opaque);
 } NodeCreationPair;
 
+/* Device Specific Code */
+
+/**
+ * add_calxeda_midway_xgmac_fdt_node
+ *
+ * Generates a simple node with following properties:
+ * compatible string, regs, interrupts, dma-coherent
+ */

Since this function is applicable to any dma-coherent device with
only mmio and irq properties to be exposed, should it be named
something more generic so that it can be reused for other devices?

+static int add_calxeda_midway_xgmac_fdt_node(SysBusDevice *sbdev, void *opaque)
+{
+    PlatformBusFDTData *data = ""
+    PlatformBusDevice *pbus = data->pbus;
+    void *fdt = data->fdt;
+    const char *parent_node = data->pbus_node_name;
+    int compat_str_len, i, ret = -1;
+    char *nodename;
+    uint32_t *irq_attr, *reg_attr;
+    uint64_t mmio_base, irq_number;
+    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    Object *obj = OBJECT(sbdev);
+
+    mmio_base = object_property_get_int(obj, "mmio[0]", NULL);
+    nodename = g_strdup_printf("%s/address@hidden" PRIx64, parent_node,
+                               vbasedev->name, mmio_base);
+    qemu_fdt_add_subnode(fdt, nodename);
+
+    compat_str_len = strlen(vdev->compat) + 1;
+    qemu_fdt_setprop(fdt, nodename, "compatible",
+                          vdev->compat, compat_str_len);
+
+    qemu_fdt_setprop(fdt, nodename, "dma-coherent", "", 0);
+
+    reg_attr = g_new(uint32_t, vbasedev->num_regions*2);
+    for (i = 0; i < vbasedev->num_regions; i++) {
+        mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);

You are missing the cpu_to_be32 for mmio_base and size.
As a result, a 0x1000 size really gets encoded as 0x100000.
If you have a device with 2 MMIO regions, this results
in the second region getting a wrong starting address in
the guest kernel, which also doesn't match the 2nd stage
mapping done by KVM. With that fix, able to test this function
with a device with 2 regions as well.

+        reg_attr[2*i] = (uint32_t)mmio_base;
+        reg_attr[2*i+1] = (uint32_t)memory_region_size(&vdev->regions[i]->mem);
+    }
+    ret = qemu_fdt_setprop(fdt, nodename, "reg", reg_attr,
+                           vbasedev->num_regions*2*sizeof(uint32_t));
+    if (ret) {
+        error_report("could not set reg property of node %s", nodename);
+        goto fail_reg;
+    }
+
+    irq_attr = g_new(uint32_t, vbasedev->num_irqs*3);
+    for (i = 0; i < vbasedev->num_irqs; i++) {
+        irq_number = platform_bus_get_irqn(pbus, sbdev , i)
+                         + data->irq_start;
+        irq_attr[3*i] = cpu_to_be32(0);
+        irq_attr[3*i+1] = cpu_to_be32(irq_number);
+        irq_attr[3*i+2] = cpu_to_be32(0x4);
+    }
+   ret = qemu_fdt_setprop(fdt, nodename, "interrupts",
+                     irq_attr, vbasedev->num_irqs*3*sizeof(uint32_t));
+    if (ret) {
+        error_report("could not set interrupts property of node %s",
+                     nodename);
+    }
+    g_free(irq_attr);
+fail_reg:
+    g_free(reg_attr);
+    g_free(nodename);
+    return ret;
+}
+
 /* list of supported dynamic sysbus devices */
 static const NodeCreationPair add_fdt_node_functions[] = {
+    {TYPE_VFIO_CALXEDA_XGMAC, add_calxeda_midway_xgmac_fdt_node},
     {"", NULL}, /* last element */
 };
 
+/* Generic Code */
+
 /**
  * add_fdt_node - add the device tree node of a dynamic sysbus device
  *