spapr: Implement dispatch tracking for tcg

Implement cpu_exec_enter/exit on ppc which calls into new methods of
the same name in PPCVirtualHypervisorClass. These are used by spapr
to implement the splpar VPA dispatch counter initially.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20190718034214.14948-2-npiggin@gmail.com>
[dwg: Removed unnecessary CONFIG_USER_ONLY checks as suggested by gkurz]
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr.c

@@ -4306,6 +4306,52 @@ PowerPCCPU *spapr_find_cpu(int vcpu_id)
     return NULL;
 }
 
+static void spapr_cpu_exec_enter(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu)
+{
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
+
+    /* These are only called by TCG, KVM maintains dispatch state */
+
+    if (spapr_cpu->vpa_addr) {
+        CPUState *cs = CPU(cpu);
+        uint32_t dispatch;
+
+        dispatch = ldl_be_phys(cs->as,
+                               spapr_cpu->vpa_addr + VPA_DISPATCH_COUNTER);
+        dispatch++;
+        if ((dispatch & 1) != 0) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "VPA: incorrect dispatch counter value for "
+                          "dispatched partition %u, correcting.\n", dispatch);
+            dispatch++;
+        }
+        stl_be_phys(cs->as,
+                    spapr_cpu->vpa_addr + VPA_DISPATCH_COUNTER, dispatch);
+    }
+}
+
+static void spapr_cpu_exec_exit(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu)
+{
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
+
+    if (spapr_cpu->vpa_addr) {
+        CPUState *cs = CPU(cpu);
+        uint32_t dispatch;
+
+        dispatch = ldl_be_phys(cs->as,
+                               spapr_cpu->vpa_addr + VPA_DISPATCH_COUNTER);
+        dispatch++;
+        if ((dispatch & 1) != 1) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "VPA: incorrect dispatch counter value for "
+                          "preempted partition %u, correcting.\n", dispatch);
+            dispatch++;
+        }
+        stl_be_phys(cs->as,
+                    spapr_cpu->vpa_addr + VPA_DISPATCH_COUNTER, dispatch);
+    }
+}
+
 static void spapr_machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -4362,6 +4408,8 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     vhc->hpte_set_r = spapr_hpte_set_r;
     vhc->get_pate = spapr_get_pate;
     vhc->encode_hpt_for_kvm_pr = spapr_encode_hpt_for_kvm_pr;
+    vhc->cpu_exec_enter = spapr_cpu_exec_enter;
+    vhc->cpu_exec_exit = spapr_cpu_exec_exit;
     xic->ics_get = spapr_ics_get;
     xic->ics_resend = spapr_ics_resend;
     xic->icp_get = spapr_icp_get;

hw/ppc/spapr_hcall.c

@@ -875,11 +875,6 @@ unmap_out:
 #define FLAGS_DEREGISTER_DTL       0x0000c00000000000ULL
 #define FLAGS_DEREGISTER_SLBSHADOW 0x0000e00000000000ULL
 
-#define VPA_MIN_SIZE           640
-#define VPA_SIZE_OFFSET        0x4
-#define VPA_SHARED_PROC_OFFSET 0x9
-#define VPA_SHARED_PROC_VAL    0x2
-
 static target_ulong register_vpa(PowerPCCPU *cpu, target_ulong vpa)
 {
     CPUState *cs = CPU(cpu);

include/hw/ppc/spapr.h

@@ -525,6 +525,13 @@ void spapr_register_hypercall(target_ulong opcode, spapr_hcall_fn fn);
 target_ulong spapr_hypercall(PowerPCCPU *cpu, target_ulong opcode,
                              target_ulong *args);
 
+/* Virtual Processor Area structure constants */
+#define VPA_MIN_SIZE           640
+#define VPA_SIZE_OFFSET        0x4
+#define VPA_SHARED_PROC_OFFSET 0x9
+#define VPA_SHARED_PROC_VAL    0x2
+#define VPA_DISPATCH_COUNTER   0x100
+
 /* ibm,set-eeh-option */
 #define RTAS_EEH_DISABLE                 0
 #define RTAS_EEH_ENABLE                  1

target/ppc/cpu.h

@@ -1224,6 +1224,10 @@ struct PPCVirtualHypervisorClass {
     void (*hpte_set_r)(PPCVirtualHypervisor *vhyp, hwaddr ptex, uint64_t pte1);
     void (*get_pate)(PPCVirtualHypervisor *vhyp, ppc_v3_pate_t *entry);
     target_ulong (*encode_hpt_for_kvm_pr)(PPCVirtualHypervisor *vhyp);
+#ifndef CONFIG_USER_ONLY
+    void (*cpu_exec_enter)(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu);
+    void (*cpu_exec_exit)(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu);
+#endif
 };
 
 #define TYPE_PPC_VIRTUAL_HYPERVISOR "ppc-virtual-hypervisor"

target/ppc/translate_init.inc.c

@@ -10469,6 +10469,28 @@ static bool ppc_cpu_is_big_endian(CPUState *cs)
 
     return !msr_le;
 }
+
+static void ppc_cpu_exec_enter(CPUState *cs)
+{
+    PowerPCCPU *cpu = POWERPC_CPU(cs);
+
+    if (cpu->vhyp) {
+        PPCVirtualHypervisorClass *vhc =
+            PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
+        vhc->cpu_exec_enter(cpu->vhyp, cpu);
+    }
+}
+
+static void ppc_cpu_exec_exit(CPUState *cs)
+{
+    PowerPCCPU *cpu = POWERPC_CPU(cs);
+
+    if (cpu->vhyp) {
+        PPCVirtualHypervisorClass *vhc =
+            PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
+        vhc->cpu_exec_exit(cpu->vhyp, cpu);
+    }
+}
 #endif
 
 static void ppc_cpu_instance_init(Object *obj)
@@ -10622,6 +10644,11 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
     cc->tcg_initialize = ppc_translate_init;
     cc->tlb_fill = ppc_cpu_tlb_fill;
 #endif
+#ifndef CONFIG_USER_ONLY
+    cc->cpu_exec_enter = ppc_cpu_exec_enter;
+    cc->cpu_exec_exit = ppc_cpu_exec_exit;
+#endif
+
     cc->disas_set_info = ppc_disas_set_info;
 
     dc->fw_name = "PowerPC,UNKNOWN";