[Qemu-devel] [QEMU-PPC] [PATCH v3 4/4] target/ppc/spapr: Enable the large decrementer for pseries-4.0

[Suraj Jitindar Singh <sjitindarsingh@gmail.com>]

Enable the large decrementer by default for the pseries-4.0 machine type.
It is disabled again by default_caps_with_cpu() for pre-POWER9 cpus
since they don't support the large decrementer.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
---
 hw/ppc/spapr.c      | 3 ++-
 hw/ppc/spapr_caps.c | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 9942b270df..1df324379f 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4318,7 +4318,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     smc->default_caps.caps[SPAPR_CAP_IBS] = SPAPR_CAP_BROKEN;
     smc->default_caps.caps[SPAPR_CAP_HPT_MAXPAGESIZE] = 16; /* 64kiB */
     smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
-    smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_OFF;
+    smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
     spapr_caps_add_properties(smc, &error_abort);
     smc->irq = &spapr_irq_xics;
     smc->dr_phb_enabled = true;
@@ -4394,6 +4394,7 @@ static void spapr_machine_3_1_class_options(MachineClass *mc)
     mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power8_v2.0");
     smc->update_dt_enabled = false;
     smc->dr_phb_enabled = false;
+    smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_OFF;
 }
 
 DEFINE_SPAPR_MACHINE(3_1, "3.1", false);
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index 1e76685199..920224d0c2 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -536,6 +536,11 @@ static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
 
     caps = smc->default_caps;
 
+    if (!ppc_type_check_compat(cputype, CPU_POWERPC_LOGICAL_3_00,
+                               0, spapr->max_compat_pvr)) {
+        caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_OFF;
+    }
+
     if (!ppc_type_check_compat(cputype, CPU_POWERPC_LOGICAL_2_07,
                                0, spapr->max_compat_pvr)) {
         caps.caps[SPAPR_CAP_HTM] = SPAPR_CAP_OFF;
-- 
2.13.6