ping: anyone got any views on this one? On 22 Jul 2014, at 19:43, Alex Bligh <a...@alex.org.uk> wrote:
> Add a machine type pc-1.0-qemu-kvm for live migrate compatibility > with qemu-kvm version 1.0. > > Signed-off-by: Alex Bligh <a...@alex.org.uk> > --- > hw/acpi/piix4.c | 49 ++++++++++++++++++++++++++++++++++++++++++++-- > hw/i386/pc_piix.c | 31 +++++++++++++++++++++++++++++ > hw/timer/i8254_common.c | 41 ++++++++++++++++++++++++++++++++++++++ > include/hw/acpi/piix4.h | 1 + > include/hw/timer/i8254.h | 2 ++ > 5 files changed, 122 insertions(+), 2 deletions(-) > > This RFC patch adds inbound migrate capability from qemu-kvm version > 1.0. The main ideas are those set out in Cole Robinson's patch here: > http://pkgs.fedoraproject.org/cgit/qemu.git/tree/0001-Fix-migration-from-qemu-kvm.patch?h=f20 > however, rather than patching statically (and breaking inbound > migration on existing machine types), I have added a new machine > type (pc-1.0-qemu-kvm) without affecting any other machine types. > > This requires 'hot patching' the VMStateDescription in a couple of > places, which in turn is less than obvious as there may be (indeed > are for i8259) derived classes. Whilst pretty nausea-inducing, this > approach has the benefit of being entirely self-contained. > > I developed this on qemu 2.0 but have forward ported it (trivially) > to master. My testing has been on a VM live-migrated-to-file from > Ubuntu Precise qemu-kvm 1.0. Testing has been light to date (i.e. > can I migrate it inbound with -S without anything complaining). > > I have not (yet) brought forward the qxl rom size (and possibly > video ram) changes in Cole's patches as I'd prefer an assessment > of whether this is the right approach first. > > diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c > index b72b34e..708db79 100644 > --- a/hw/acpi/piix4.c > +++ b/hw/acpi/piix4.c > @@ -267,8 +267,9 @@ static const VMStateDescription vmstate_memhp_state = { > }; > > /* qemu-kvm 1.2 uses version 3 but advertised as 2 > - * To support incoming qemu-kvm 1.2 migration, change version_id > - * and minimum_version_id to 2 below (which breaks migration from > + * To support incoming qemu-kvm 1.2 migration, we support > + * via a command line option a change to minimum_version_id > + * of 2 in a _compat structure (which breaks migration from > * qemu 1.2). > * > */ > @@ -307,6 +308,34 @@ static const VMStateDescription vmstate_acpi = { > } > }; > > +static const VMStateDescription vmstate_acpi_compat = { > + .name = "piix4_pm", > + .version_id = 3, > + .minimum_version_id = 2, > + .minimum_version_id_old = 1, > + .load_state_old = acpi_load_old, > + .post_load = vmstate_acpi_post_load, > + .fields = (VMStateField[]) { > + VMSTATE_PCI_DEVICE(parent_obj, PIIX4PMState), > + VMSTATE_UINT16(ar.pm1.evt.sts, PIIX4PMState), > + VMSTATE_UINT16(ar.pm1.evt.en, PIIX4PMState), > + VMSTATE_UINT16(ar.pm1.cnt.cnt, PIIX4PMState), > + VMSTATE_STRUCT(apm, PIIX4PMState, 0, vmstate_apm, APMState), > + VMSTATE_TIMER(ar.tmr.timer, PIIX4PMState), > + VMSTATE_INT64(ar.tmr.overflow_time, PIIX4PMState), > + VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE), > + VMSTATE_STRUCT_TEST( > + acpi_pci_hotplug.acpi_pcihp_pci_status[ACPI_PCIHP_BSEL_DEFAULT], > + PIIX4PMState, > + vmstate_test_no_use_acpi_pci_hotplug, > + 2, vmstate_pci_status, > + struct AcpiPciHpPciStatus), > + VMSTATE_PCI_HOTPLUG(acpi_pci_hotplug, PIIX4PMState, > + vmstate_test_use_acpi_pci_hotplug), > + VMSTATE_END_OF_LIST() > + } > +}; > + > static void piix4_reset(void *opaque) > { > PIIX4PMState *s = opaque; > @@ -619,6 +648,22 @@ static void piix4_pm_class_init(ObjectClass *klass, void > *data) > adevc->ospm_status = piix4_ospm_status; > } > > +void piix4_pm_class_fix_compat(void) > +{ > + GSList *el, *devices = object_class_get_list(TYPE_DEVICE, false); > + /* > + * Change the vmstate field in this class and any derived classes > + * if not overriden. As no other classes should be using this > + * vmstate, we can simply iterate the class list > + */ > + for (el = devices; el; el = el->next) { > + DeviceClass *dc = el->data; > + if (dc->vmsd == &vmstate_acpi) { > + dc->vmsd = &vmstate_acpi_compat; > + } > + } > +} > + > static const TypeInfo piix4_pm_info = { > .name = TYPE_PIIX4_PM, > .parent = TYPE_PCI_DEVICE, > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > index 7081c08..e400ea6 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -49,6 +49,8 @@ > #include "hw/acpi/acpi.h" > #include "cpu.h" > #include "qemu/error-report.h" > +#include "hw/acpi/piix4.h" > +#include "hw/timer/i8254.h" > #ifdef CONFIG_XEN > # include <xen/hvm/hvm_info_table.h> > #endif > @@ -386,6 +388,15 @@ static void pc_init_pci_1_2(MachineState *machine) > pc_init_pci(machine); > } > > +/* PC machine init function for qemu-kvm 1.0 */ > +static void pc_init_pci_1_2_qemu_kvm(MachineState *machine) > +{ > + piix4_pm_class_fix_compat(); > + pit_common_class_fix_compat(); > + pc_compat_1_2(machine); > + pc_init_pci(machine); > +} > + > /* PC init function for pc-0.10 to pc-0.13 */ > static void pc_init_pci_no_kvmclock(MachineState *machine) > { > @@ -644,6 +655,25 @@ static QEMUMachine pc_machine_v1_0 = { > .hw_version = "1.0", > }; > > +#define PC_COMPAT_1_0_QEMU_KVM \ > + PC_COMPAT_1_0,\ > + {\ > + .driver = "cirrus-vga",\ > + .property = "vgamem_mb",\ > + .value = stringify(16),\ > + } > + > +static QEMUMachine pc_machine_v1_0_qemu_kvm = { > + PC_I440FX_1_2_MACHINE_OPTIONS, > + .name = "pc-1.0-qemu-kvm", > + .init = pc_init_pci_1_2_qemu_kvm, > + .compat_props = (GlobalProperty[]) { > + PC_COMPAT_1_0_QEMU_KVM, > + { /* end of list */ } > + }, > + .hw_version = "1.0", > +}; > + > #define PC_COMPAT_0_15 \ > PC_COMPAT_1_0 > > @@ -886,6 +916,7 @@ static void pc_machine_init(void) > qemu_register_pc_machine(&pc_machine_v1_2); > qemu_register_pc_machine(&pc_machine_v1_1); > qemu_register_pc_machine(&pc_machine_v1_0); > + qemu_register_pc_machine(&pc_machine_v1_0_qemu_kvm); > qemu_register_pc_machine(&pc_machine_v0_15); > qemu_register_pc_machine(&pc_machine_v0_14); > qemu_register_pc_machine(&pc_machine_v0_13); > diff --git a/hw/timer/i8254_common.c b/hw/timer/i8254_common.c > index 07345f6..511ea05 100644 > --- a/hw/timer/i8254_common.c > +++ b/hw/timer/i8254_common.c > @@ -275,6 +275,29 @@ static const VMStateDescription vmstate_pit_common = { > } > }; > > +static const VMStateDescription vmstate_pit_common_compat = { > + .name = "i8254", > + .version_id = 3, > + .minimum_version_id = 2, > + .minimum_version_id_old = 1, > + .load_state_old = pit_load_old, > + .pre_save = pit_dispatch_pre_save, > + .post_load = pit_dispatch_post_load, > + .fields = (VMStateField[]) { > + /* qemu-kvm version_id=2 had 'flags' here which is equivalent > + * This fixes incoming migration from qemu-kvm 1.0, but breaks > + * incoming migration from qemu < 1.1 > + */ > + /* VMSTATE_UINT32_V(channels[0].irq_disabled, PITCommonState, 3), */ > + VMSTATE_UINT32(channels[0].irq_disabled, PITCommonState), > + VMSTATE_STRUCT_ARRAY(channels, PITCommonState, 3, 2, > + vmstate_pit_channel, PITChannelState), > + VMSTATE_INT64(channels[0].next_transition_time, > + PITCommonState), /* formerly irq_timer */ > + VMSTATE_END_OF_LIST() > + } > +}; > + > static void pit_common_class_init(ObjectClass *klass, void *data) > { > DeviceClass *dc = DEVICE_CLASS(klass); > @@ -289,6 +312,24 @@ static void pit_common_class_init(ObjectClass *klass, > void *data) > dc->cannot_instantiate_with_device_add_yet = true; > } > > +void pit_common_class_fix_compat(void) > +{ > + GSList *el, *devices = object_class_get_list(TYPE_DEVICE, false); > + /* > + * Change the vmstate field in this class and any derived classes > + * if not overriden. As no other classes should be using this > + * vmstate, we can simply iterate the class list > + */ > + for (el = devices; el; el = el->next) { > + DeviceClass *dc = el->data; > + if (dc->vmsd == &vmstate_pit_common) { > + dc->vmsd = &vmstate_pit_common_compat; > + } > + } > + > + g_slist_free(devices); > +} > + > static const TypeInfo pit_common_type = { > .name = TYPE_PIT_COMMON, > .parent = TYPE_ISA_DEVICE, > diff --git a/include/hw/acpi/piix4.h b/include/hw/acpi/piix4.h > index 65e6fd7..811d88f 100644 > --- a/include/hw/acpi/piix4.h > +++ b/include/hw/acpi/piix4.h > @@ -4,5 +4,6 @@ > #include "qemu/typedefs.h" > > Object *piix4_pm_find(void); > +void piix4_pm_class_fix_compat(void); > > #endif > diff --git a/include/hw/timer/i8254.h b/include/hw/timer/i8254.h > index 4349033..0126424 100644 > --- a/include/hw/timer/i8254.h > +++ b/include/hw/timer/i8254.h > @@ -72,4 +72,6 @@ static inline ISADevice *kvm_pit_init(ISABus *bus, int base) > void pit_set_gate(ISADevice *dev, int channel, int val); > void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info); > > +void pit_common_class_fix_compat(void); > + > #endif /* !HW_I8254_H */ > -- > 1.7.9.5 > > > -- Alex Bligh
