From: Igor Mammedov <imammedo@redhat.com>

This reverts commit bf1ecc8dad6061914730a2a2d57af6b37c3a4f8d
which broke cpu hotplug in x86 after migration to older QEMU

Fixes: bf1ecc8dad606 (w/acpi: Update ACPI `_STA` method with QOM vCPU ACPI Hotplug states)
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20241112170258.2996640-3-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/core/cpu.h |  1 -
 hw/acpi/cpu.c         | 38 ++++----------------------------------
 2 files changed, 4 insertions(+), 35 deletions(-)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index db8a6fbc6e..e7de77dc6d 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -159,7 +159,6 @@ struct CPUClass {
     void (*query_cpu_fast)(CPUState *cpu, CpuInfoFast *value);
     int64_t (*get_arch_id)(CPUState *cpu);
     bool (*cpu_persistent_status)(CPUState *cpu);
-    bool (*cpu_enabled_status)(CPUState *cpu);
     void (*set_pc)(CPUState *cpu, vaddr value);
     vaddr (*get_pc)(CPUState *cpu);
     int (*gdb_read_register)(CPUState *cpu, GByteArray *buf, int reg);
diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index 23443f09a5..9b03b4292e 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -50,18 +50,6 @@ void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList ***list)
     }
 }
 
-static bool check_cpu_enabled_status(DeviceState *dev)
-{
-    CPUClass *k = dev ? CPU_GET_CLASS(dev) : NULL;
-    CPUState *cpu = CPU(dev);
-
-    if (cpu && (!k->cpu_enabled_status || k->cpu_enabled_status(cpu))) {
-        return true;
-    }
-
-    return false;
-}
-
 static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size)
 {
     uint64_t val = 0;
@@ -75,11 +63,10 @@ static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size)
     cdev = &cpu_st->devs[cpu_st->selector];
     switch (addr) {
     case ACPI_CPU_FLAGS_OFFSET_RW: /* pack and return is_* fields */
-        val |= check_cpu_enabled_status(DEVICE(cdev->cpu)) ? 1 : 0;
+        val |= cdev->cpu ? 1 : 0;
         val |= cdev->is_inserting ? 2 : 0;
         val |= cdev->is_removing  ? 4 : 0;
         val |= cdev->fw_remove  ? 16 : 0;
-        val |= cdev->cpu ? 32 : 0;
         trace_cpuhp_acpi_read_flags(cpu_st->selector, val);
         break;
     case ACPI_CPU_CMD_DATA_OFFSET_RW:
@@ -362,7 +349,6 @@ const VMStateDescription vmstate_cpu_hotplug = {
 #define CPU_REMOVE_EVENT  "CRMV"
 #define CPU_EJECT_EVENT   "CEJ0"
 #define CPU_FW_EJECT_EVENT "CEJF"
-#define CPU_PRESENT       "CPRS"
 
 void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
                     build_madt_cpu_fn build_madt_cpu, hwaddr base_addr,
@@ -423,9 +409,7 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
         aml_append(field, aml_named_field(CPU_EJECT_EVENT, 1));
         /* tell firmware to do device eject, write only */
         aml_append(field, aml_named_field(CPU_FW_EJECT_EVENT, 1));
-        /* 1 if present, read only */
-        aml_append(field, aml_named_field(CPU_PRESENT, 1));
-        aml_append(field, aml_reserved_field(2));
+        aml_append(field, aml_reserved_field(3));
         aml_append(field, aml_named_field(CPU_COMMAND, 8));
         aml_append(cpu_ctrl_dev, field);
 
@@ -455,7 +439,6 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
         Aml *ctrl_lock = aml_name("%s.%s", cphp_res_path, CPU_LOCK);
         Aml *cpu_selector = aml_name("%s.%s", cphp_res_path, CPU_SELECTOR);
         Aml *is_enabled = aml_name("%s.%s", cphp_res_path, CPU_ENABLED);
-        Aml *is_present = aml_name("%s.%s", cphp_res_path, CPU_PRESENT);
         Aml *cpu_cmd = aml_name("%s.%s", cphp_res_path, CPU_COMMAND);
         Aml *cpu_data = aml_name("%s.%s", cphp_res_path, CPU_DATA);
         Aml *ins_evt = aml_name("%s.%s", cphp_res_path, CPU_INSERT_EVENT);
@@ -484,26 +467,13 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
         {
             Aml *idx = aml_arg(0);
             Aml *sta = aml_local(0);
-            Aml *ifctx2;
-            Aml *else_ctx;
 
             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
             aml_append(method, aml_store(idx, cpu_selector));
             aml_append(method, aml_store(zero, sta));
-            ifctx = aml_if(aml_equal(is_present, one));
+            ifctx = aml_if(aml_equal(is_enabled, one));
             {
-                ifctx2 = aml_if(aml_equal(is_enabled, one));
-                {
-                    /* cpu is present and enabled */
-                    aml_append(ifctx2, aml_store(aml_int(0xF), sta));
-                }
-                aml_append(ifctx, ifctx2);
-                else_ctx = aml_else();
-                {
-                    /* cpu is present but disabled */
-                    aml_append(else_ctx, aml_store(aml_int(0xD), sta));
-                }
-                aml_append(ifctx, else_ctx);
+                aml_append(ifctx, aml_store(aml_int(0xF), sta));
             }
             aml_append(method, ifctx);
             aml_append(method, aml_release(ctrl_lock));
-- 
MST