[Qemu-devel] [PATCH 4/4] spapr: Add RTAS sysparm SPLPAR Characteristics

[Sam Bobroff <sam.bobroff@au1.ibm.com>]

Add support for the SPLPAR Characteristics parameter to the emulated
RTAS call ibm,get-system-parameter.

The support provides just enough information to allow "cat
/proc/powerpc/lparcfg" to succeed without generating a kernel error
message.

Without this patch the above command will produce the following kernel
message: arch/powerpc/platforms/pseries/lparcfg.c \
parse_system_parameter_string Error calling get-system-parameter \
(0xfffffffd)

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
---
 hw/ppc/spapr_rtas.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 8d94845..4270e7a 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -224,6 +224,7 @@ static void rtas_stop_self(PowerPCCPU *cpu, sPAPREnvironment *spapr,
     env->msr = 0;
 }
 
+#define SPLPAR_CHARACTERISTICS      20
 #define DIAGNOSTICS_RUN_MODE        42
 #define UUID                        48
 
@@ -238,8 +239,20 @@ static void rtas_ibm_get_system_parameter(PowerPCCPU *cpu,
     target_ulong length = rtas_ld(args, 2);
     target_ulong ret = RTAS_OUT_SUCCESS;
     uint8_t zero = 0;
+    uint8_t param_buf[64];
+    int param_len;
 
     switch (parameter) {
+    case SPLPAR_CHARACTERISTICS:
+        param_len = snprintf((char *)param_buf, sizeof param_buf,
+                             "MaxEntCap=%d,MaxPlatProcs=%d",
+                             max_cpus, smp_cpus);
+        if (param_len >= 0) {
+            rtas_st_buffer(buffer, length, param_buf, param_len);
+        } else {
+            ret = RTAS_OUT_HW_ERROR;
+        }
+        break;
     case DIAGNOSTICS_RUN_MODE:
         rtas_st_buffer(buffer, length, &zero, sizeof zero);
         break;
-- 
1.9.0