[Qemu-devel] [PATCH v5 1/4] spapr: Implement VPA dispatch counter and prod bit on tcg

[Nicholas Piggin <npiggin@gmail.com>]

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 these splpar elements, used in subsequent changes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
Changes since v4:
- Store to VPA on the way out as well.
- Increment the dispatch counter directly in the VPA, which means it will
  migrate with guest memory the same as KVM.
- Prod need not be migrated, add a comment.

 hw/ppc/spapr.c                  | 41 +++++++++++++++++++++++++++++++++
 hw/ppc/spapr_cpu_core.c         |  4 +++-
 hw/ppc/spapr_hcall.c            |  5 ----
 include/hw/ppc/spapr.h          |  7 ++++++
 include/hw/ppc/spapr_cpu_core.h |  1 +
 target/ppc/cpu.h                |  2 ++
 target/ppc/translate_init.inc.c | 25 ++++++++++++++++++++
 7 files changed, 79 insertions(+), 6 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 821f0d4a49..13c423347e 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4302,6 +4302,45 @@ 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 */
+
+    spapr_cpu->prod = false;
+    if (spapr_cpu->vpa_addr) {
+        CPUState *cs = CPU(cpu);
+        unsigned int dispatch;
+
+        dispatch = ldl_be_phys(cs->as,
+                               spapr_cpu->vpa_addr + VPA_DISPATCH_COUNTER);
+        dispatch++;
+        if ((dispatch & 1) != 0) /* guest set the "wrong" value */
+            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);
+        unsigned int dispatch;
+
+        dispatch = ldl_be_phys(cs->as,
+                               spapr_cpu->vpa_addr + VPA_DISPATCH_COUNTER);
+        dispatch++;
+        if ((dispatch & 1) != 1) /* guest set the "wrong" value */
+            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);
@@ -4358,6 +4397,8 @@ 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;
diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index 5621fb9a3d..54abf5308c 100644
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -261,6 +261,7 @@ error:
 static PowerPCCPU *spapr_create_vcpu(SpaprCpuCore *sc, int i, Error **errp)
 {
     SpaprCpuCoreClass *scc = SPAPR_CPU_CORE_GET_CLASS(sc);
+    SpaprCpuState *spapr_cpu;
     CPUCore *cc = CPU_CORE(sc);
     Object *obj;
     char *id;
@@ -287,7 +288,8 @@ static PowerPCCPU *spapr_create_vcpu(SpaprCpuCore *sc, int i, Error **errp)
         goto err;
     }
 
-    cpu->machine_data = g_new0(SpaprCpuState, 1);
+    spapr_cpu = g_new0(SpaprCpuState, 1);
+    cpu->machine_data = spapr_cpu;
 
     object_unref(obj);
     return cpu;
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 6808d4cda8..e615881ac4 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -874,11 +874,6 @@ 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);
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 60553d32c4..5d36eec9d0 100644
--- a/include/hw/ppc/spapr.h
+++ b/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
diff --git a/include/hw/ppc/spapr_cpu_core.h b/include/hw/ppc/spapr_cpu_core.h
index f9645a7290..a40cd08ea0 100644
--- a/include/hw/ppc/spapr_cpu_core.h
+++ b/include/hw/ppc/spapr_cpu_core.h
@@ -46,6 +46,7 @@ typedef struct SpaprCpuState {
     uint64_t vpa_addr;
     uint64_t slb_shadow_addr, slb_shadow_size;
     uint64_t dtl_addr, dtl_size;
+    bool prod; /* not migrated, only used to improve dispatch latencies */
     struct ICPState *icp;
     struct XiveTCTX *tctx;
 } SpaprCpuState;
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index c9beba2a5c..78d6504acb 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1224,6 +1224,8 @@ 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);
+    void (*cpu_exec_enter)(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu);
+    void (*cpu_exec_exit)(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu);
 };
 
 #define TYPE_PPC_VIRTUAL_HYPERVISOR "ppc-virtual-hypervisor"
diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c
index 86fc8f2e31..58d4a93b23 100644
--- a/target/ppc/translate_init.inc.c
+++ b/target/ppc/translate_init.inc.c
@@ -10473,6 +10473,28 @@ static bool ppc_cpu_is_big_endian(CPUState *cs)
 }
 #endif
 
+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);
+    }
+}
+
 static void ppc_cpu_instance_init(Object *obj)
 {
     PowerPCCPU *cpu = POWERPC_CPU(obj);
@@ -10624,6 +10646,9 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
     cc->tcg_initialize = ppc_translate_init;
     cc->tlb_fill = ppc_cpu_tlb_fill;
 #endif
+    cc->cpu_exec_enter = ppc_cpu_exec_enter;
+    cc->cpu_exec_exit = ppc_cpu_exec_exit;
+
     cc->disas_set_info = ppc_disas_set_info;
 
     dc->fw_name = "PowerPC,UNKNOWN";
-- 
2.20.1