[PATCH v4 04/15] spapr: nested: keep nested-hv related code restricted to its API.

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

spapr_exit_nested and spapr_get_pate_nested_hv contains code which
is specific to nested-hv API. Isolating code flows based on API
helps extending it to be used with different API as well.

Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
---
 include/hw/ppc/spapr_nested.h |  4 ++++
 hw/ppc/spapr.c                |  7 ++++++-
 hw/ppc/spapr_caps.c           |  1 +
 hw/ppc/spapr_nested.c         | 27 ++++++++++++++++++++++++---
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h
index 2488ea98da..3f07c81c3d 100644
--- a/include/hw/ppc/spapr_nested.h
+++ b/include/hw/ppc/spapr_nested.h
@@ -5,6 +5,8 @@
 
 typedef struct SpaprMachineStateNested {
     uint64_t ptcr;
+    uint8_t api;
+#define NESTED_API_KVM_HV  1
 } SpaprMachineStateNested;
 
 /*
@@ -103,4 +105,6 @@ void spapr_exit_nested(PowerPCCPU *cpu, int excp);
 typedef struct SpaprMachineState SpaprMachineState;
 bool spapr_get_pate_nested_hv(SpaprMachineState *spapr, PowerPCCPU *cpu,
                               target_ulong lpid, ppc_v3_pate_t *entry);
+void spapr_nested_init(SpaprMachineState *spapr);
+uint8_t spapr_nested_api(SpaprMachineState *spapr);
 #endif /* HW_SPAPR_NESTED_H */
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 97b69c0e42..51a1be027a 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1376,7 +1376,11 @@ static bool spapr_get_pate(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu,
         entry->dw1 = spapr->patb_entry;
         return true;
     } else {
-        return spapr_get_pate_nested_hv(spapr, cpu, lpid, entry);
+        assert(spapr_nested_api(spapr));
+        if (spapr_nested_api(spapr) == NESTED_API_KVM_HV) {
+            return spapr_get_pate_nested_hv(spapr, cpu, lpid, entry);
+        }
+        return false;
     }
 }
 
@@ -3443,6 +3447,7 @@ static void spapr_instance_init(Object *obj)
         spapr_get_host_serial, spapr_set_host_serial);
     object_property_set_description(obj, "host-serial",
         "Host serial number to advertise in guest device tree");
+    spapr_nested_init(spapr);
 }
 
 static void spapr_machine_finalizefn(Object *obj)
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index f0c2f4de78..721ddad23b 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -487,6 +487,7 @@ static void cap_nested_kvm_hv_apply(SpaprMachineState *spapr,
             error_append_hint(errp, "Try appending -machine cap-nested-hv=off "
                                     "or use threads=1 with -smp\n");
         }
+        spapr->nested.api = NESTED_API_KVM_HV;
         spapr_unregister_nested_hv(); /* reset across reboots */
         spapr_register_nested_hv();
     }
diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c
index e43e867295..9096dd96a4 100644
--- a/hw/ppc/spapr_nested.c
+++ b/hw/ppc/spapr_nested.c
@@ -8,6 +8,16 @@
 #include "hw/ppc/spapr_nested.h"
 #include "mmu-book3s-v3.h"
 
+void spapr_nested_init(SpaprMachineState *spapr)
+{
+    spapr->nested.api = 0;
+}
+
+uint8_t spapr_nested_api(SpaprMachineState *spapr)
+{
+    return spapr->nested.api;
+}
+
 #ifdef CONFIG_TCG
 
 bool spapr_get_pate_nested_hv(SpaprMachineState *spapr, PowerPCCPU *cpu,
@@ -302,7 +312,7 @@ static target_ulong h_enter_nested(PowerPCCPU *cpu,
     return env->gpr[3];
 }
 
-void spapr_exit_nested(PowerPCCPU *cpu, int excp)
+static void spapr_exit_nested_hv(PowerPCCPU *cpu, int excp)
 {
     CPUPPCState *env = &cpu->env;
     SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
@@ -314,8 +324,6 @@ void spapr_exit_nested(PowerPCCPU *cpu, int excp)
     struct kvmppc_pt_regs *regs;
     hwaddr len;
 
-    assert(spapr_cpu->in_nested);
-
     nested_save_state(&l2_state, cpu);
     hsrr0 = env->spr[SPR_HSRR0];
     hsrr1 = env->spr[SPR_HSRR1];
@@ -405,6 +413,19 @@ void spapr_exit_nested(PowerPCCPU *cpu, int excp)
     address_space_unmap(CPU(cpu)->as, regs, len, len, true);
 }
 
+void spapr_exit_nested(PowerPCCPU *cpu, int excp)
+{
+    SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
+
+    assert(spapr_cpu->in_nested);
+    if (spapr_nested_api(spapr) == NESTED_API_KVM_HV) {
+        spapr_exit_nested_hv(cpu, excp);
+    } else {
+        g_assert_not_reached();
+    }
+}
+
 void spapr_register_nested_hv(void)
 {
     spapr_register_hypercall(KVMPPC_H_SET_PARTITION_TABLE, h_set_ptbl);
-- 
2.39.3