target-ppc/kvm: Enable in-kernel TCE acceleration for multi-tce

This enables in-kernel handling of H_PUT_TCE_INDIRECT and
H_STUFF_TCE hypercalls. The host kernel support is there since v4.6,
in particular d3695aa4f452
("KVM: PPC: Add support for multiple-TCE hcalls").

H_PUT_TCE is already accelerated and does not need any special enablement.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr.c

@@ -2361,10 +2361,12 @@ static void ppc_spapr_init(MachineState *machine)
 
     qemu_register_boot_set(spapr_boot_set, spapr);
 
-    /* to stop and start vmclock */
     if (kvm_enabled()) {
+        /* to stop and start vmclock */
         qemu_add_vm_change_state_handler(cpu_ppc_clock_vm_state_change,
                                          &spapr->tb);
+
+        kvmppc_spapr_enable_inkernel_multitce();
     }
 }
 

target/ppc/kvm.c

@@ -2198,6 +2198,20 @@ bool kvmppc_spapr_use_multitce(void)
     return cap_spapr_multitce;
 }
 
+int kvmppc_spapr_enable_inkernel_multitce(void)
+{
+    int ret;
+
+    ret = kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_ENABLE_HCALL, 0,
+                            H_PUT_TCE_INDIRECT, 1);
+    if (!ret) {
+        ret = kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_ENABLE_HCALL, 0,
+                                H_STUFF_TCE, 1);
+    }
+
+    return ret;
+}
+
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t page_shift,
                               uint64_t bus_offset, uint32_t nb_table,
                               int *pfd, bool need_vfio)

target/ppc/kvm_ppc.h

@@ -39,6 +39,7 @@ target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu,
 #ifndef CONFIG_USER_ONLY
 off_t kvmppc_alloc_rma(void **rma);
 bool kvmppc_spapr_use_multitce(void);
+int kvmppc_spapr_enable_inkernel_multitce(void);
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t page_shift,
                               uint64_t bus_offset, uint32_t nb_table,
                               int *pfd, bool need_vfio);
@@ -180,6 +181,11 @@ static inline bool kvmppc_spapr_use_multitce(void)
     return false;
 }
 
+static inline int kvmppc_spapr_enable_inkernel_multitce(void)
+{
+    return -1;
+}
+
 static inline void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t page_shift,
                                             uint64_t bus_offset,
                                             uint32_t nb_table,