The PXB implementation doesn't allow firmware (SeaBIOS or OVMF) to boot
off devices behind the PXB. This happens because the
sysbus_get_fw_dev_path() function in "hw/core/sysbus.c" doesn't have
enough information to format a unique identifier for the PXB in question,
and consequently the OpenFirmware device path passed down to the guest
firmware in the "bootorder" fw_cfg file is unusable for identifying the
boot device.
For example, the command line fragment
-device pxb,id=bridge1,bus_nr=4 \
\
-netdev user,id=netdev0 \
-device e1000,netdev=netdev0,bus=bridge1,addr=2,bootindex=0
results in the following "bootorder" entry:
/pci/pci-bridge@0/ethernet@2/ethernet-phy@0
The initial "pci" node is formatted by sysbus_get_fw_dev_path(), and the
resultant OpenFirmware device path is independent of bus_nr=4 -- and
therefore it is useless for identifying the device.
In this patch we insert a dummy bus between the main sysbus and the
TYPE_PXB_HOST device. Formatting child addresses is a bus class level
responsibility, which is exactly what we'll use here.
After the patch, the same command line fragment results in the following
OpenFirmware device path in the "bootorder" fw_cfg file:
/extra-pci-roots/pxbhost@4/pci-bridge@0/ethernet@2/ethernet-phy@0
The original, initial "/pci" fragment has been replaced with
"/extra-pci-roots/pxbhost@4", which (a) looks better, (b) provides all the
necessary information. sysbus_get_fw_dev_path() formats the first node
("extra-pci-roots") as always, and the new function
extra_pci_roots_bus_get_fw_dev_path() formats the second one
("pxbhost@4").
Here's the comparison ("diff -u -b -U28") between the "info qtree"
outputs, before and after (the hpet device is the first common line):
> --- qtree.before 2015-06-10 18:16:44.903359633 +0200
> +++ qtree.after 2015-06-10 18:19:01.904139538 +0200
> @@ -1,30 +1,33 @@
> bus: main-system-bus
> type System
> + dev: extra-pci-roots, id ""
> + bus: extra-pci-roots-bus.0
> + type extra-pci-roots-bus
> dev: pxb-host, id ""
> bus: pxb-internal
> type pxb-bus
> dev: pci-basic-bridge, id "bridge1"
> chassis_nr = 4 (0x4)
> addr = 00.0
> romfile = ""
> rombar = 1 (0x1)
> multifunction = false
> command_serr_enable = true
> class PCI bridge, addr 04:00.0, pci id 1b36:000a (sub 0000:0000)
> bus: bridge1
> type PCI
> dev: e1000, id ""
> mac = "52:54:00:12:34:56"
> vlan = <null>
> netdev = "netdev0"
> autonegotiation = true
> mitigation = true
> addr = 02.0
> romfile = ""
> rombar = 1 (0x1)
> multifunction = false
> command_serr_enable = true
> class Ethernet controller, addr 05:02.0, pci id 8086:100e (sub
> 1af4:1100)
> bar 0: mem at 0x88100000 [0x8811ffff]
> bar 1: i/o at 0xd000 [0xd03f]
> dev: hpet, id ""
Cc: Markus Armbruster <arm...@redhat.com>
Cc: Marcel Apfelbaum <mar...@redhat.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
---
Notes:
v2:
- new in v2, addressing the "bootorder" fw_cfg issue discussed earlier
- Cc'd Markus, because I probably butchered a handful of QOM rules in
this patch :)
hw/pci-bridge/pci_expander_bridge.c | 45 +++++++++++++++++++++++++++++++++++--
1 file changed, 43 insertions(+), 2 deletions(-)
diff --git a/hw/pci-bridge/pci_expander_bridge.c
b/hw/pci-bridge/pci_expander_bridge.c
index c7a085d..30e93d6 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -19,6 +19,15 @@
#include "qemu/error-report.h"
#include "sysemu/numa.h"
+/*
+ * We'll insert a dummy bus between the main sysbus and TYPE_PXB_HOST, because
+ * the main sysbus doesn't know how to format the bus number of the extra root
+ * bus in sysbus_get_fw_dev_path(). We'll use this dummy bus just for
+ * formatting that.
+ */
+#define TYPE_EXTRA_PCI_ROOTS_DEV "extra-pci-roots"
+#define TYPE_EXTRA_PCI_ROOTS_BUS "extra-pci-roots-bus"
+
#define TYPE_PXB_BUS "pxb-bus"
#define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
@@ -93,7 +102,8 @@ static void pxb_host_class_init(ObjectClass *class, void
*data)
DeviceClass *dc = DEVICE_CLASS(class);
PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
- dc->fw_name = "pci";
+ dc->fw_name = "pxbhost";
+ dc->bus_type = TYPE_EXTRA_PCI_ROOTS_BUS;
hc->root_bus_path = pxb_host_root_bus_path;
}
@@ -151,6 +161,8 @@ static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
static int pxb_dev_initfn(PCIDevice *dev)
{
PXBDev *pxb = PXB_DEV(dev);
+ DeviceState *extra_pci_roots_dev;
+ BusState *extra_pci_roots_bus;
DeviceState *ds, *bds;
PCIBus *bus;
const char *dev_name = NULL;
@@ -165,7 +177,10 @@ static int pxb_dev_initfn(PCIDevice *dev)
dev_name = dev->qdev.id;
}
- ds = qdev_create(NULL, TYPE_PXB_HOST);
+ extra_pci_roots_dev = qdev_create(NULL, TYPE_EXTRA_PCI_ROOTS_DEV);
+ extra_pci_roots_bus = qbus_create(TYPE_EXTRA_PCI_ROOTS_BUS,
+ extra_pci_roots_dev, NULL);
+ ds = qdev_create(extra_pci_roots_bus, TYPE_PXB_HOST);
bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
bus->parent_dev = dev;
@@ -221,11 +236,37 @@ static const TypeInfo pxb_dev_info = {
.class_init = pxb_dev_class_init,
};
+static char *extra_pci_roots_bus_get_fw_dev_path(DeviceState *dev)
+{
+ return g_strdup_printf("%s@%x", qdev_fw_name(dev),
+ pxb_bus_num(PCI_HOST_BRIDGE(dev)->bus));
+}
+
+static void extra_pci_roots_bus_class_init(ObjectClass *klass, void *data)
+{
+ BusClass *k = BUS_CLASS(klass);
+
+ k->get_fw_dev_path = extra_pci_roots_bus_get_fw_dev_path;
+}
+
+static const TypeInfo extra_pci_roots_bus_info = {
+ .name = TYPE_EXTRA_PCI_ROOTS_BUS,
+ .parent = TYPE_BUS,
+ .class_init = extra_pci_roots_bus_class_init,
+};
+
+static const TypeInfo extra_pci_roots_bus_dev_info = {
+ .name = TYPE_EXTRA_PCI_ROOTS_DEV,
+ .parent = TYPE_SYS_BUS_DEVICE,
+};
+
static void pxb_register_types(void)
{
type_register_static(&pxb_bus_info);
type_register_static(&pxb_host_info);
type_register_static(&pxb_dev_info);
+ type_register_static(&extra_pci_roots_bus_info);
+ type_register_static(&extra_pci_roots_bus_dev_info);
}
type_init(pxb_register_types)
--
1.8.3.1
