[Qemu-devel] [PATCH v3 1/3] target-i386: add a subsection for migrating vcpu's TSC rate

[Haozhong Zhang <haozhong.zhang@intel.com>]

A new subsection 'vmstate_tsc_khz' is added to migrate vcpu's TSC
rate. For the backwards compatibility, this subsection is not migrated
on pc-*-2.4 and older machine types.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
 hw/i386/pc.c          |  1 +
 hw/i386/pc_piix.c     |  1 +
 hw/i386/pc_q35.c      |  1 +
 include/hw/i386/pc.h  |  1 +
 target-i386/cpu.h     |  1 +
 target-i386/machine.c | 21 +++++++++++++++++++++
 6 files changed, 26 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 0cb8afd..2f2fc93 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1952,6 +1952,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
 
     pcmc->get_hotplug_handler = mc->get_hotplug_handler;
+    pcmc->save_tsc_khz = true;
     mc->get_hotplug_handler = pc_get_hotpug_handler;
     mc->cpu_index_to_socket_id = pc_cpu_index_to_socket_id;
     mc->default_boot_order = "cad";
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 393dcc4..fc71321 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -487,6 +487,7 @@ static void pc_i440fx_2_4_machine_options(MachineClass *m)
     m->alias = NULL;
     m->is_default = 0;
     pcmc->broken_reserved_end = true;
+    pcmc->save_tsc_khz = false;
     SET_MACHINE_COMPAT(m, PC_COMPAT_2_4);
 }
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 2f8f396..858ed69 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -385,6 +385,7 @@ static void pc_q35_2_4_machine_options(MachineClass *m)
     pc_q35_2_5_machine_options(m);
     m->alias = NULL;
     pcmc->broken_reserved_end = true;
+    pcmc->save_tsc_khz = false;
     SET_MACHINE_COMPAT(m, PC_COMPAT_2_4);
 }
 
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 606dbc2..875d099 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -60,6 +60,7 @@ struct PCMachineClass {
 
     /*< public >*/
     bool broken_reserved_end;
+    bool save_tsc_khz;
     HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
                                            DeviceState *dev);
 };
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 62f7879..4f2f4a3 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -970,6 +970,7 @@ typedef struct CPUX86State {
     uint32_t sipi_vector;
     bool tsc_valid;
     int64_t tsc_khz;
+    int64_t tsc_khz_saved;
     void *kvm_xsave_buf;
 
     uint64_t mcg_cap;
diff --git a/target-i386/machine.c b/target-i386/machine.c
index a18e16e..4d8157c 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -775,6 +775,26 @@ static const VMStateDescription vmstate_xss = {
     }
 };
 
+static bool tsc_khz_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+    MachineClass *mc = MACHINE_GET_CLASS((qdev_get_machine()));
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(mc);
+    return env->tsc_khz_saved && pcmc->save_tsc_khz;
+}
+
+static const VMStateDescription vmstate_tsc_khz = {
+    .name = "cpu/tsc_khz",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = tsc_khz_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT64(env.tsc_khz_saved, X86CPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 VMStateDescription vmstate_x86_cpu = {
     .name = "cpu",
     .version_id = 12,
@@ -895,6 +915,7 @@ VMStateDescription vmstate_x86_cpu = {
         &vmstate_msr_hyperv_runtime,
         &vmstate_avx512,
         &vmstate_xss,
+        &vmstate_tsc_khz,
         NULL
     }
 };
-- 
2.4.8