[RFC PATCH 5/5] spapr: Allow up to 8 threads SMT configuration

[Nicholas Piggin]

TCG now supports multi-threaded configuration at least enough for
pseries to be functional enough to boot Linux.

This requires PIR and TIR be set, because that's how sibling thread
matching is done.

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
 hw/ppc/spapr.c          | 4 ++--
 hw/ppc/spapr_cpu_core.c | 7 +++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index dcb7f1c70a..11074cefea 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2524,8 +2524,8 @@ static void spapr_set_vsmt_mode(SpaprMachineState *spapr, 
Error **errp)
     int ret;
     unsigned int smp_threads = ms->smp.threads;
 
-    if (!kvm_enabled() && (smp_threads > 1)) {
-        error_setg(errp, "TCG cannot support more than 1 thread/core "
+    if (!kvm_enabled() && (smp_threads > 8)) {
+        error_setg(errp, "TCG cannot support more than 8 threads/core "
                    "on a pseries machine");
         return;
     }
diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index 9b88dd549a..f35ee600f1 100644
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -255,7 +255,7 @@ static void spapr_cpu_core_unrealize(DeviceState *dev)
 }
 
 static bool spapr_realize_vcpu(PowerPCCPU *cpu, SpaprMachineState *spapr,
-                               SpaprCpuCore *sc, Error **errp)
+                               SpaprCpuCore *sc, int thread_nr, Error **errp)
 {
     CPUPPCState *env = &cpu->env;
     CPUState *cs = CPU(cpu);
@@ -267,6 +267,9 @@ static bool spapr_realize_vcpu(PowerPCCPU *cpu, 
SpaprMachineState *spapr,
     cpu_ppc_set_vhyp(cpu, PPC_VIRTUAL_HYPERVISOR(spapr));
     kvmppc_set_papr(cpu);
 
+    env->spr_cb[SPR_PIR].default_value = cs->cpu_index;
+    env->spr_cb[SPR_TIR].default_value = thread_nr;
+
     /* Set time-base frequency to 512 MHz. vhyp must be set first. */
     cpu_ppc_tb_init(env, SPAPR_TIMEBASE_FREQ);
 
@@ -337,7 +340,7 @@ static void spapr_cpu_core_realize(DeviceState *dev, Error 
**errp)
     for (i = 0; i < cc->nr_threads; i++) {
         sc->threads[i] = spapr_create_vcpu(sc, i, errp);
         if (!sc->threads[i] ||
-            !spapr_realize_vcpu(sc->threads[i], spapr, sc, errp)) {
+            !spapr_realize_vcpu(sc->threads[i], spapr, sc, i, errp)) {
             spapr_cpu_core_unrealize(dev);
             return;
         }
-- 
2.40.1