3 files changed, 32 insertions, 0 deletions

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 8e24d7dc50..37fd7a1411 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2097,6 +2097,7 @@ static const VMStateDescription vmstate_spapr = {
         &vmstate_spapr_cap_nested_kvm_hv,
         &vmstate_spapr_dtb,
         &vmstate_spapr_cap_large_decr,
+        &vmstate_spapr_cap_ccf_assist,
         NULL
     }
 };
@@ -4312,6 +4313,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     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_ON;
+    smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
     spapr_caps_add_properties(smc, &error_abort);
     smc->irq = &spapr_irq_xics;
     smc->dr_phb_enabled = true;
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index ca35b5153d..c5d381f183 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -441,6 +441,21 @@ static void cap_large_decr_cpu_apply(sPAPRMachineState *spapr,
     ppc_store_lpcr(cpu, lpcr);
 }
 
+static void cap_ccf_assist_apply(sPAPRMachineState *spapr, uint8_t val,
+                                 Error **errp)
+{
+    uint8_t kvm_val = kvmppc_get_cap_count_cache_flush_assist();
+
+    if (tcg_enabled() && val) {
+        /* TODO - for now only allow broken for TCG */
+        error_setg(errp,
+"Requested count cache flush assist capability level not supported by tcg, try cap-ccf-assist=off");
+    } else if (kvm_enabled() && (val > kvm_val)) {
+        error_setg(errp,
+"Requested count cache flush assist capability level not supported by kvm, try cap-ccf-assist=off");
+    }
+}
+
 sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
     [SPAPR_CAP_HTM] = {
         .name = "htm",
@@ -530,6 +545,15 @@ sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
         .apply = cap_large_decr_apply,
         .cpu_apply = cap_large_decr_cpu_apply,
     },
+    [SPAPR_CAP_CCF_ASSIST] = {
+        .name = "ccf-assist",
+        .description = "Count Cache Flush Assist via HW Instruction",
+        .index = SPAPR_CAP_CCF_ASSIST,
+        .get = spapr_cap_get_bool,
+        .set = spapr_cap_set_bool,
+        .type = "bool",
+        .apply = cap_ccf_assist_apply,
+    },
 };
 
 static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
@@ -664,6 +688,7 @@ SPAPR_CAP_MIG_STATE(sbbc, SPAPR_CAP_SBBC);
 SPAPR_CAP_MIG_STATE(ibs, SPAPR_CAP_IBS);
 SPAPR_CAP_MIG_STATE(nested_kvm_hv, SPAPR_CAP_NESTED_KVM_HV);
 SPAPR_CAP_MIG_STATE(large_decr, SPAPR_CAP_LARGE_DECREMENTER);
+SPAPR_CAP_MIG_STATE(ccf_assist, SPAPR_CAP_CCF_ASSIST);
 
 void spapr_caps_init(sPAPRMachineState *spapr)
 {
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 4aa8036fc0..15bdd30a12 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1693,6 +1693,8 @@ static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu,
     uint8_t safe_cache = spapr_get_cap(spapr, SPAPR_CAP_CFPC);
     uint8_t safe_bounds_check = spapr_get_cap(spapr, SPAPR_CAP_SBBC);
     uint8_t safe_indirect_branch = spapr_get_cap(spapr, SPAPR_CAP_IBS);
+    uint8_t count_cache_flush_assist = spapr_get_cap(spapr,
+                                                     SPAPR_CAP_CCF_ASSIST);
 
     switch (safe_cache) {
     case SPAPR_CAP_WORKAROUND:
@@ -1733,6 +1735,9 @@ static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu,
         break;
     case SPAPR_CAP_WORKAROUND:
         behaviour |= H_CPU_BEHAV_FLUSH_COUNT_CACHE;
+        if (count_cache_flush_assist) {
+            characteristics |= H_CPU_CHAR_BCCTR_FLUSH_ASSIST;
+        }
         break;
     default: /* broken */
         assert(safe_indirect_branch == SPAPR_CAP_BROKEN);