[Qemu-devel] [PATCH v7 07/15] spapr_rtas: add ibm, configure-connector RTAS interface

[Michael Roth]

This interface is used to fetch an OF device-tree nodes that describes a
newly-attached device to guest. It is called multiple times to walk the
device-tree node and fetch individual properties into a 'workarea'/buffer
provided by the guest.

The device-tree is generated by QEMU and passed to an sPAPRDRConnector during
the initial hotplug operation, and the state of these RTAS calls is tracked by
the sPAPRDRConnector. When the last of these properties is successfully
fetched, we report as special return value to the guest and transition
the device to a 'configured' state on the QEMU/DRC side.

See docs/specs/ppc-spapr-hotplug.txt for a complete description of
this interface.

Signed-off-by: Michael Roth <address@hidden>
---
 hw/ppc/spapr_rtas.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 147 insertions(+)

diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index f80beb2..b4047af 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -418,6 +418,151 @@ static void rtas_get_sensor_state(PowerPCCPU *cpu, 
sPAPREnvironment *spapr,
     rtas_st(rets, 1, entity_sense);
 }
 
+/* configure-connector work area offsets, int32_t units for field
+ * indexes, bytes for field offset/len values.
+ *
+ * as documented by PAPR+ v2.7, 13.5.3.5
+ */
+#define CC_IDX_NODE_NAME_OFFSET 2
+#define CC_IDX_PROP_NAME_OFFSET 2
+#define CC_IDX_PROP_LEN 3
+#define CC_IDX_PROP_DATA_OFFSET 4
+#define CC_VAL_DATA_OFFSET ((CC_IDX_PROP_DATA_OFFSET + 1) * 4)
+#define CC_WA_LEN 4096
+
+typedef struct sPAPRDRCCState {
+    void *fdt;
+    int fdt_offset;
+    int fdt_depth;
+} sPAPRDRCCState;
+
+static void init_ccs(void *opaque, void *fdt, int fdt_start_offset)
+{
+    sPAPRDRCCState *ccs = opaque;
+    ccs->fdt_offset = fdt_start_offset;
+    ccs->fdt = fdt;
+    ccs->fdt_depth = 0;
+}
+
+static void reset_ccs(void *opaque)
+{
+    g_free(opaque);
+}
+
+static void rtas_ibm_configure_connector(PowerPCCPU *cpu,
+                                         sPAPREnvironment *spapr,
+                                         uint32_t token, uint32_t nargs,
+                                         target_ulong args, uint32_t nret,
+                                         target_ulong rets)
+{
+    uint64_t wa_addr;
+    uint64_t wa_offset;
+    uint32_t drc_index;
+    sPAPRDRConnector *drc;
+    sPAPRDRConnectorClass *drck;
+    sPAPRDRCCState *ccs;
+    sPAPRDRCCResponse resp = SPAPR_DR_CC_RESPONSE_CONTINUE;
+    int rc;
+
+    if (nargs != 2 || nret != 1) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    wa_addr = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 0);
+
+    drc_index = rtas_ld(wa_addr, 0);
+    drc = spapr_dr_connector_by_index(drc_index);
+    if (!drc) {
+        DPRINTF("rtas_ibm_configure_connector: invalid DRC index: %xh\n",
+                drc_index);
+        rc = RTAS_OUT_PARAM_ERROR;
+        goto out;
+    }
+
+    drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+    ccs = drck->get_configure_connector_state(drc);
+    if (!ccs) {
+        ccs = g_new0(sPAPRDRCCState, 1);
+        if (!drck->begin_configure_connector(drc, init_ccs, reset_ccs, ccs)) {
+            DPRINTF("rtas_ibm_configure_connector: DRC index: %xh "
+                    "unavailable for configuration\n",
+                    drc_index);
+            rc = RTAS_OUT_PARAM_ERROR;
+            goto out;
+        }
+    }
+
+    do {
+        uint32_t tag;
+        const char *name;
+        const struct fdt_property *prop;
+        int fdt_offset_next, prop_len;
+
+        tag = fdt_next_tag(ccs->fdt, ccs->fdt_offset, &fdt_offset_next);
+
+        switch (tag) {
+        case FDT_BEGIN_NODE:
+            ccs->fdt_depth++;
+            name = fdt_get_name(ccs->fdt, ccs->fdt_offset, NULL);
+
+            /* provide the name of the next OF node */
+            wa_offset = CC_VAL_DATA_OFFSET;
+            rtas_st(wa_addr, CC_IDX_NODE_NAME_OFFSET, wa_offset);
+            rtas_st_buffer_direct(wa_addr + wa_offset, CC_WA_LEN - wa_offset,
+                                  (uint8_t *)name, strlen(name) + 1);
+            resp = SPAPR_DR_CC_RESPONSE_NEXT_CHILD;
+            break;
+        case FDT_END_NODE:
+            ccs->fdt_depth--;
+            if (ccs->fdt_depth == 0) {
+                drck->complete_configure_connector(drc);
+                /* ccs should be free at this point */
+                ccs = NULL;
+                resp = SPAPR_DR_CC_RESPONSE_SUCCESS;
+            } else {
+                resp = SPAPR_DR_CC_RESPONSE_PREV_PARENT;
+            }
+            break;
+        case FDT_PROP:
+            prop = fdt_get_property_by_offset(ccs->fdt, ccs->fdt_offset,
+                                              &prop_len);
+            name = fdt_string(ccs->fdt, fdt32_to_cpu(prop->nameoff));
+
+            /* provide the name of the next OF property */
+            wa_offset = CC_VAL_DATA_OFFSET;
+            rtas_st(wa_addr, CC_IDX_PROP_NAME_OFFSET, wa_offset);
+            rtas_st_buffer_direct(wa_addr + wa_offset, CC_WA_LEN - wa_offset,
+                                  (uint8_t *)name, strlen(name) + 1);
+
+            /* provide the length and value of the OF property. data gets
+             * placed immediately after NULL terminator of the OF property's
+             * name string
+             */
+            wa_offset += strlen(name) + 1,
+            rtas_st(wa_addr, CC_IDX_PROP_LEN, prop_len);
+            rtas_st(wa_addr, CC_IDX_PROP_DATA_OFFSET, wa_offset);
+            rtas_st_buffer_direct(wa_addr + wa_offset, CC_WA_LEN - wa_offset,
+                                  (uint8_t *)((struct fdt_property 
*)prop)->data,
+                                  prop_len);
+            resp = SPAPR_DR_CC_RESPONSE_NEXT_PROPERTY;
+            break;
+        case FDT_END:
+            resp = SPAPR_DR_CC_RESPONSE_ERROR;
+        default:
+            /* keep seeking for an actionable tag */
+            break;
+        }
+        if (ccs) {
+            ccs->fdt_offset = fdt_offset_next;
+        }
+    } while (resp == SPAPR_DR_CC_RESPONSE_CONTINUE);
+
+    rc = resp;
+out:
+    rtas_st(rets, 0, rc);
+}
+
 static struct rtas_call {
     const char *name;
     spapr_rtas_fn fn;
@@ -551,6 +696,8 @@ static void core_rtas_register_types(void)
                         rtas_set_indicator);
     spapr_rtas_register(RTAS_GET_SENSOR_STATE, "get-sensor-state",
                         rtas_get_sensor_state);
+    spapr_rtas_register(RTAS_IBM_CONFIGURE_CONNECTOR, 
"ibm,configure-connector",
+                        rtas_ibm_configure_connector);
 }
 
 type_init(core_rtas_register_types)
-- 
1.9.1