@@ -1717,7 +1717,7 @@ static int spapr_populate_cpu_dt(CPUState *cs, void *fdt, int offset)
return 0;
}
-static void spapr_cpu_hotplug_add(CPUState *cs)
+static int spapr_cpu_hotplug_add(CPUState *cs)
{
int i, j;
sPAPRDrcEntry *drc_entry;
@@ -1740,6 +1740,11 @@ static void spapr_cpu_hotplug_add(CPUState *cs)
PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
char *nodename;
int index = ppc_get_vcpu_dt_id(cpu);
+ int smt = kvmppc_smt_threads();
+
+ if ((index % smt) != 0) {
+ return -1;
+ }
drc_entry = spapr_cpu_to_drc_entry(cpu->cpu_dt_id + SPAPR_DRC_CPU_ID_BASE);
g_assert(drc_entry);
@@ -1797,14 +1802,17 @@ static void spapr_cpu_hotplug_add(CPUState *cs)
ccs->fdt = fdt;
ccs->offset_start = offset;
ccs->state = CC_STATE_PENDING;
+
+ return 0;
}
static void spapr_cpu_added_req(Notifier *n, void *opaque)
{
CPUState *cs = CPU(opaque);
- spapr_cpu_hotplug_add(cs);
- spapr_cpu_hotplug_add_event(cs);
+ if (!spapr_cpu_hotplug_add(cs)) {
+ spapr_cpu_hotplug_add_event(cs);
+ }
return;
}
@@ -2193,6 +2201,7 @@ static void ppc_hot_add_cpu(const int64_t id, Error **errp)
{
CPUState *cs;
PowerPCCPU *cpu;
+ int i;
if (id < 0) {
error_setg(errp, "Invalid CPU id: %" PRIi64, id);
@@ -2213,8 +2222,16 @@ static void ppc_hot_add_cpu(const int64_t id, Error **errp)
return;
}
- cpu = ppc_new_cpu(current_cpu_model);
- spapr_cpu_reset(cpu);
+ if ((id % smp_threads) != 0) {
+ error_setg(errp, "Invalid CPU id: %" PRIi64
+ ", only cores can be added", id);
+ return;
+ }
+
+ for (i = 0; i < smp_threads; i++) {
+ cpu = ppc_new_cpu(current_cpu_model);
+ spapr_cpu_reset(cpu);
+ }
}
static void spapr_machine_class_init(ObjectClass *oc, void *data)
pseries kernels support hot-plugging CPUs in core granularity. i,e., when a core is hotplugged, guest kernel tries to bring up all the threads in that core. This doesn't match 1-to-1 with QEMU hotplug semantics where cpu-add monitor command hotplugs 1 CPU at a time. While it is still an open question as to what kind of CPU hotplug semantics we should support here, this patch restricts cpu-add monitor command to allow only CPU cores to be added. All the threads of the hot-plugged core at onlined at once. Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> --- hw/ppc/spapr.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-)