[Qemu-devel] [PATCH v8 03/16] spapr_rtas: add get/set-power-level RTAS interfaces

[Michael Roth <mdroth@linux.vnet.ibm.com>]

From: Nathan Fontenot <nfont@linux.vnet.ibm.com>

These interfaces manage the power domains that guest devices are
assigned to and are used to power on/off devices. Currently we
only utilize 1 power domain, the 'live-insertion' domain, which
automates power management of plugged/unplugged devices, essentially
making these calls no-ops, but the RTAS interfaces are still required
by guest hotplug code and PAPR+.

See docs/specs/ppc-spapr-hotplug.txt for a complete description of
these interfaces.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr_rtas.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 0f1ae55..d7694cd 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -245,6 +245,56 @@ static void rtas_ibm_os_term(PowerPCCPU *cpu,
     rtas_st(rets, 0, ret);
 }
 
+static void rtas_set_power_level(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                                 uint32_t token, uint32_t nargs,
+                                 target_ulong args, uint32_t nret,
+                                 target_ulong rets)
+{
+    int32_t power_domain;
+
+    if (nargs != 2 || nret != 2) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    /* we currently only use a single, "live insert" powerdomain for
+     * hotplugged/dlpar'd resources, so the power is always live/full (100)
+     */
+    power_domain = rtas_ld(args, 0);
+    if (power_domain != -1) {
+        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
+        return;
+    }
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+    rtas_st(rets, 1, 100);
+}
+
+static void rtas_get_power_level(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                                  uint32_t token, uint32_t nargs,
+                                  target_ulong args, uint32_t nret,
+                                  target_ulong rets)
+{
+    int32_t power_domain;
+
+    if (nargs != 1 || nret != 2) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    /* we currently only use a single, "live insert" powerdomain for
+     * hotplugged/dlpar'd resources, so the power is always live/full (100)
+     */
+    power_domain = rtas_ld(args, 0);
+    if (power_domain != -1) {
+        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
+        return;
+    }
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+    rtas_st(rets, 1, 100);
+}
+
 static struct rtas_call {
     const char *name;
     spapr_rtas_fn fn;
@@ -370,6 +420,10 @@ static void core_rtas_register_types(void)
                         rtas_ibm_set_system_parameter);
     spapr_rtas_register(RTAS_IBM_OS_TERM, "ibm,os-term",
                         rtas_ibm_os_term);
+    spapr_rtas_register(RTAS_SET_POWER_LEVEL, "set-power-level",
+                        rtas_set_power_level);
+    spapr_rtas_register(RTAS_GET_POWER_LEVEL, "get-power-level",
+                        rtas_get_power_level);
 }
 
 type_init(core_rtas_register_types)
-- 
1.9.1