[Qemu-devel] [PATCH 4/8] pseries: Implement automatic PAPR VIO address allocation

[Alexander Graf <agraf@suse.de>]

From: David Gibson <david@gibson.dropbear.id.au>

PAPR virtual IO (VIO) devices require a unique, but otherwise arbitrary,
"address" used as a token to the hypercalls which manipulate them.

Currently the pseries machine code does an ok job of allocating these
addresses when the legacy -net nic / -serial and so forth options are used
but will fail to allocate them properly when using -device.

Specifically, you can use -device if all addresses are explicitly assigned.
Without explicit assignment, only one VIO device of each type (network,
console, SCSI) will be assigned properly, any further ones will attempt
to take the same address leading to a fatal error.

This patch fixes the situation by adding a proper address allocator to the
VIO "bus" code.  This is used both by -device and the legacy options and
default devices.  Addresses can still be explicitly assigned with -device
options if desired.

This patch changes the (guest visible) numbering of VIO devices, but since
their addresses are discovered using the device tree and already differ
from the numbering found on existing PowerVM systems, this does not break
compatibility.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/spapr.c       |    7 +++----
 hw/spapr_llan.c  |    5 ++---
 hw/spapr_vio.c   |   54 ++++++++++++++++++++++++++++++++++--------------------
 hw/spapr_vio.h   |   13 ++++++-------
 hw/spapr_vscsi.c |    5 ++---
 hw/spapr_vty.c   |    5 ++---
 6 files changed, 49 insertions(+), 40 deletions(-)

diff --git a/hw/spapr.c b/hw/spapr.c
index bfaf260..cca20f9 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -631,8 +631,7 @@ static void ppc_spapr_init(ram_addr_t ram_size,
 
     for (i = 0; i < MAX_SERIAL_PORTS; i++) {
         if (serial_hds[i]) {
-            spapr_vty_create(spapr->vio_bus, SPAPR_VTY_BASE_ADDRESS + i,
-                             serial_hds[i]);
+            spapr_vty_create(spapr->vio_bus, serial_hds[i]);
         }
     }
 
@@ -650,14 +649,14 @@ static void ppc_spapr_init(ram_addr_t ram_size,
         }
 
         if (strcmp(nd->model, "ibmveth") == 0) {
-            spapr_vlan_create(spapr->vio_bus, 0x1000 + i, nd);
+            spapr_vlan_create(spapr->vio_bus, nd);
         } else {
             pci_nic_init_nofail(&nd_table[i], nd->model, NULL);
         }
     }
 
     for (i = 0; i <= drive_get_max_bus(IF_SCSI); i++) {
-        spapr_vscsi_create(spapr->vio_bus, 0x2000 + i);
+        spapr_vscsi_create(spapr->vio_bus);
     }
 
     if (rma_size < (MIN_RMA_SLOF << 20)) {
diff --git a/hw/spapr_llan.c b/hw/spapr_llan.c
index e18d2eb..8313043 100644
--- a/hw/spapr_llan.c
+++ b/hw/spapr_llan.c
@@ -204,12 +204,11 @@ static int spapr_vlan_init(VIOsPAPRDevice *sdev)
     return 0;
 }
 
-void spapr_vlan_create(VIOsPAPRBus *bus, uint32_t reg, NICInfo *nd)
+void spapr_vlan_create(VIOsPAPRBus *bus, NICInfo *nd)
 {
     DeviceState *dev;
 
     dev = qdev_create(&bus->bus, "spapr-vlan");
-    qdev_prop_set_uint32(dev, "reg", reg);
 
     qdev_set_nic_properties(dev, nd);
 
@@ -480,7 +479,7 @@ static target_ulong h_multicast_ctrl(CPUPPCState *env, sPAPREnvironment *spapr,
 }
 
 static Property spapr_vlan_properties[] = {
-    DEFINE_SPAPR_PROPERTIES(VIOsPAPRVLANDevice, sdev, 0x1000, 0x10000000),
+    DEFINE_SPAPR_PROPERTIES(VIOsPAPRVLANDevice, sdev, 0x10000000),
     DEFINE_NIC_PROPERTIES(VIOsPAPRVLANDevice, nicconf),
     DEFINE_PROP_END_OF_LIST(),
 };
diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index fccf48b..315ab80 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -620,28 +620,22 @@ static void rtas_quiesce(sPAPREnvironment *spapr, uint32_t token,
     rtas_st(rets, 0, 0);
 }
 
-static int spapr_vio_check_reg(VIOsPAPRDevice *sdev)
+static VIOsPAPRDevice *reg_conflict(VIOsPAPRDevice *dev)
 {
-    VIOsPAPRDevice *other_sdev;
+    VIOsPAPRBus *bus = DO_UPCAST(VIOsPAPRBus, bus, dev->qdev.parent_bus);
     DeviceState *qdev;
-    VIOsPAPRBus *sbus;
-
-    sbus = DO_UPCAST(VIOsPAPRBus, bus, sdev->qdev.parent_bus);
+    VIOsPAPRDevice *other;
 
     /*
-     * Check two device aren't given clashing addresses by the user (or some
-     * other mechanism). We have to open code this because we have to check
-     * for matches with devices other than us.
+     * Check for a device other than the given one which is already
+     * using the requested address. We have to open code this because
+     * the given dev might already be in the list.
      */
-    QTAILQ_FOREACH(qdev, &sbus->bus.children, sibling) {
-        other_sdev = DO_UPCAST(VIOsPAPRDevice, qdev, qdev);
+    QTAILQ_FOREACH(qdev, &bus->bus.children, sibling) {
+        other = DO_UPCAST(VIOsPAPRDevice, qdev, qdev);
 
-        if (other_sdev != sdev && other_sdev->reg == sdev->reg) {
-            fprintf(stderr, "vio: %s and %s devices conflict at address %#x\n",
-                    object_get_typename(OBJECT(sdev)),
-                    object_get_typename(OBJECT(qdev)),
-                    sdev->reg);
-            return -EEXIST;
+        if (other != dev && other->reg == dev->reg) {
+            return other;
         }
     }
 
@@ -667,11 +661,30 @@ static int spapr_vio_busdev_init(DeviceState *qdev)
     VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
     char *id;
-    int ret;
 
-    ret = spapr_vio_check_reg(dev);
-    if (ret) {
-        return ret;
+    if (dev->reg != -1) {
+        /*
+         * Explicitly assigned address, just verify that no-one else
+         * is using it.  other mechanism). We have to open code this
+         * rather than using spapr_vio_find_by_reg() because sdev
+         * itself is already in the list.
+         */
+        VIOsPAPRDevice *other = reg_conflict(dev);
+
+        if (other) {
+            fprintf(stderr, "vio: %s and %s devices conflict at address %#x\n",
+                    object_get_typename(OBJECT(qdev)),
+                    object_get_typename(OBJECT(&other->qdev)),
+                    dev->reg);
+            return -1;
+        }
+    } else {
+        /* Need to assign an address */
+        VIOsPAPRBus *bus = DO_UPCAST(VIOsPAPRBus, bus, dev->qdev.parent_bus);
+
+        do {
+            dev->reg = bus->next_reg++;
+        } while (reg_conflict(dev));
     }
 
     /* Don't overwrite ids assigned on the command line */
@@ -731,6 +744,7 @@ VIOsPAPRBus *spapr_vio_bus_init(void)
 
     qbus = qbus_create(&spapr_vio_bus_info, dev, "spapr-vio");
     bus = DO_UPCAST(VIOsPAPRBus, bus, qbus);
+    bus->next_reg = 0x1000;
 
     /* hcall-vio */
     spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
diff --git a/hw/spapr_vio.h b/hw/spapr_vio.h
index 10ab359..87816e4 100644
--- a/hw/spapr_vio.h
+++ b/hw/spapr_vio.h
@@ -32,8 +32,6 @@ enum VIOsPAPR_TCEAccess {
     SPAPR_TCE_RW = 3,
 };
 
-#define SPAPR_VTY_BASE_ADDRESS     0x30000000
-
 #define TYPE_VIO_SPAPR_DEVICE "vio-spapr-device"
 #define VIO_SPAPR_DEVICE(obj) \
      OBJECT_CHECK(VIOsPAPRDevice, (obj), TYPE_VIO_SPAPR_DEVICE)
@@ -82,13 +80,14 @@ struct VIOsPAPRDevice {
     VIOsPAPR_CRQ crq;
 };
 
-#define DEFINE_SPAPR_PROPERTIES(type, field, default_reg, default_dma_window) \
-        DEFINE_PROP_UINT32("reg", type, field.reg, default_reg), \
+#define DEFINE_SPAPR_PROPERTIES(type, field, default_dma_window)       \
+        DEFINE_PROP_UINT32("reg", type, field.reg, -1),                \
         DEFINE_PROP_UINT32("dma-window", type, field.rtce_window_size, \
                            default_dma_window)
 
 struct VIOsPAPRBus {
     BusState bus;
+    uint32_t next_reg;
     int (*init)(VIOsPAPRDevice *dev);
     int (*devnode)(VIOsPAPRDevice *dev, void *fdt, int node_off);
 };
@@ -119,9 +118,9 @@ int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq);
 
 VIOsPAPRDevice *vty_lookup(sPAPREnvironment *spapr, target_ulong reg);
 void vty_putchars(VIOsPAPRDevice *sdev, uint8_t *buf, int len);
-void spapr_vty_create(VIOsPAPRBus *bus, uint32_t reg, CharDriverState *chardev);
-void spapr_vlan_create(VIOsPAPRBus *bus, uint32_t reg, NICInfo *nd);
-void spapr_vscsi_create(VIOsPAPRBus *bus, uint32_t reg);
+void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev);
+void spapr_vlan_create(VIOsPAPRBus *bus, NICInfo *nd);
+void spapr_vscsi_create(VIOsPAPRBus *bus);
 
 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus);
 
diff --git a/hw/spapr_vscsi.c b/hw/spapr_vscsi.c
index 538e0b7..037867a 100644
--- a/hw/spapr_vscsi.c
+++ b/hw/spapr_vscsi.c
@@ -918,12 +918,11 @@ static int spapr_vscsi_init(VIOsPAPRDevice *dev)
     return 0;
 }
 
-void spapr_vscsi_create(VIOsPAPRBus *bus, uint32_t reg)
+void spapr_vscsi_create(VIOsPAPRBus *bus)
 {
     DeviceState *dev;
 
     dev = qdev_create(&bus->bus, "spapr-vscsi");
-    qdev_prop_set_uint32(dev, "reg", reg);
 
     qdev_init_nofail(dev);
 }
@@ -946,7 +945,7 @@ static int spapr_vscsi_devnode(VIOsPAPRDevice *dev, void *fdt, int node_off)
 }
 
 static Property spapr_vscsi_properties[] = {
-    DEFINE_SPAPR_PROPERTIES(VSCSIState, vdev, 0x2000, 0x10000000),
+    DEFINE_SPAPR_PROPERTIES(VSCSIState, vdev, 0x10000000),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/spapr_vty.c b/hw/spapr_vty.c
index a30c040..c9674f3 100644
--- a/hw/spapr_vty.c
+++ b/hw/spapr_vty.c
@@ -123,18 +123,17 @@ static target_ulong h_get_term_char(CPUPPCState *env, sPAPREnvironment *spapr,
     return H_SUCCESS;
 }
 
-void spapr_vty_create(VIOsPAPRBus *bus, uint32_t reg, CharDriverState *chardev)
+void spapr_vty_create(VIOsPAPRBus *bus, CharDriverState *chardev)
 {
     DeviceState *dev;
 
     dev = qdev_create(&bus->bus, "spapr-vty");
-    qdev_prop_set_uint32(dev, "reg", reg);
     qdev_prop_set_chr(dev, "chardev", chardev);
     qdev_init_nofail(dev);
 }
 
 static Property spapr_vty_properties[] = {
-    DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev, SPAPR_VTY_BASE_ADDRESS, 0),
+    DEFINE_SPAPR_PROPERTIES(VIOsPAPRVTYDevice, sdev, 0),
     DEFINE_PROP_CHR("chardev", VIOsPAPRVTYDevice, chardev),
     DEFINE_PROP_END_OF_LIST(),
 };
-- 
1.6.0.2