[Qemu-devel] [QEMU-PPC] [PATCH V2 2/3] ppc/spapr-caps: Convert spapr-cap-ibs to be a boolean

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

The spapr-cap cap-ibs can only have values broken or fixed as there is
no workaround. Currently setting the value workaround will hit an assert
if the guest makes the hcall h_get_cpu_characteristics.

Thus this capability is better suited to being represented as a boolean.
Setting this to OFF corresponds to the old BROKEN, that is no indirect
branch serialisation. Setting this to ON corresponds to the old FIXED,
that is indirect branches are serialised.

Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
---
 hw/ppc/spapr.c      |  2 +-
 hw/ppc/spapr_caps.c | 12 ++++++------
 target/ppc/kvm.c    |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 32a876be56..969db6cde2 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3886,7 +3886,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     smc->default_caps.caps[SPAPR_CAP_DFP] = SPAPR_CAP_ON;
     smc->default_caps.caps[SPAPR_CAP_CFPC] = SPAPR_CAP_BROKEN;
     smc->default_caps.caps[SPAPR_CAP_SBBC] = SPAPR_CAP_BROKEN;
-    smc->default_caps.caps[SPAPR_CAP_IBS] = SPAPR_CAP_BROKEN;
+    smc->default_caps.caps[SPAPR_CAP_IBS] = SPAPR_CAP_OFF;
     spapr_caps_add_properties(smc, &error_abort);
 }
 
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index e69d308560..05997b0842 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -207,9 +207,9 @@ static void cap_safe_indirect_branch_apply(sPAPRMachineState *spapr,
 {
     if (tcg_enabled() && val) {
         /* TODO - for now only allow broken for TCG */
-        error_setg(errp, "Requested safe indirect branch capability level not supported by tcg, try a different value for cap-ibs");
+        error_setg(errp, "Indirect Branch Serialisation support not available, try cap-ibs=off");
     } else if (kvm_enabled() && (val > kvmppc_get_cap_safe_indirect_branch())) {
-        error_setg(errp, "Requested safe indirect branch capability level not supported by kvm, try a different value for cap-ibs");
+        error_setg(errp, "Indirect Branch Serialisation support not available, try cap-ibs=off");
     }
 }
 
@@ -263,11 +263,11 @@ sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
     },
     [SPAPR_CAP_IBS] = {
         .name = "ibs",
-        .description = "Indirect Branch Serialisation" VALUE_DESC_TRISTATE,
+        .description = "Indirect Branch Serialisation",
         .index = SPAPR_CAP_IBS,
-        .get = spapr_cap_get_tristate,
-        .set = spapr_cap_set_tristate,
-        .type = "string",
+        .get = spapr_cap_get_bool,
+        .set = spapr_cap_set_bool,
+        .type = "bool",
         .apply = cap_safe_indirect_branch_apply,
     },
 };
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 9842b3bb12..3e3e5f9c1f 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2495,7 +2495,7 @@ static void kvmppc_get_cpu_characteristics(KVMState *s)
     }
     /* Parse and set cap_ppc_safe_indirect_branch */
     if (c.character & H_CPU_CHAR_BCCTRL_SERIALISED) {
-        cap_ppc_safe_indirect_branch = 2;
+        cap_ppc_safe_indirect_branch = 1;
     }
 }
 
-- 
2.13.6