* Greg Kurz (gk...@linux.vnet.ibm.com) wrote:
> Since QEMU 2.4, the migration stream begins with a configuration section.
> It is known to break migration of pseries machine from older QEMU. It is
> possible to fix this in the pseries compat code but it will then break
> migration of old pseries from latest QEMU.
>
> As an alternative, this patch introduces a new machine property which
> allows to ignore the abscence of configuration section during incoming
> migration. It boils to adding:
>
> -machine config-section=off
>
> Using this property only makes sense when migrating from an older
> QEMU. It has no effect on outgoing migration.
Hi Greg,
So I'm mostly OK with this, but please change it to:
'require-config-section' and the bool similarly.
We've effectively got 2 separate things:
a) Whether a config section is sent
b) Whether a config section is required upon reception
I want to make sure the naming makes it obvious which is being changed,
and you're only affecting (b).
Dave
>
> Suggested-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com>
> ---
> hw/core/machine.c | 21 +++++++++++++++++++++
> include/hw/boards.h | 1 +
> migration/savevm.c | 21 +++++++++++++++------
> qemu-options.hx | 3 ++-
> 4 files changed, 39 insertions(+), 7 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 6d1a0d8eebc4..4a7322988fb5 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -312,6 +312,20 @@ static bool machine_get_suppress_vmdesc(Object *obj,
> Error **errp)
> return ms->suppress_vmdesc;
> }
>
> +static void machine_set_config_section(Object *obj, bool value, Error **errp)
> +{
> + MachineState *ms = MACHINE(obj);
> +
> + ms->config_section = value;
> +}
> +
> +static bool machine_get_config_section(Object *obj, Error **errp)
> +{
> + MachineState *ms = MACHINE(obj);
> +
> + return ms->config_section;
> +}
> +
> static int error_on_sysbus_device(SysBusDevice *sbdev, void *opaque)
> {
> error_report("Option '-device %s' cannot be handled by this machine",
> @@ -365,6 +379,7 @@ static void machine_initfn(Object *obj)
> ms->kvm_shadow_mem = -1;
> ms->dump_guest_core = true;
> ms->mem_merge = true;
> + ms->config_section = true;
>
> object_property_add_str(obj, "accel",
> machine_get_accel, machine_set_accel, NULL);
> @@ -467,6 +482,12 @@ static void machine_initfn(Object *obj)
> object_property_set_description(obj, "suppress-vmdesc",
> "Set on to disable self-describing
> migration",
> NULL);
> + object_property_add_bool(obj, "config-section",
> + machine_get_config_section,
> + machine_set_config_section, NULL);
> + object_property_set_description(obj, "config-section",
> + "Set on/off to accept migration
> with/without configuration section",
> + NULL);
>
> /* Register notifier when init is done for sysbus sanity checks */
> ms->sysbus_notifier.notify = machine_init_notify;
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 0f30959e2e3b..853bb5905ec1 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -128,6 +128,7 @@ struct MachineState {
> char *firmware;
> bool iommu;
> bool suppress_vmdesc;
> + bool config_section;
>
> ram_addr_t ram_size;
> ram_addr_t maxram_size;
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 94f2894243ce..3795489aeaec 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1847,6 +1847,12 @@ static int qemu_loadvm_state_main(QEMUFile *f,
> MigrationIncomingState *mis)
> return 0;
> }
>
> +static bool must_receive_configuration(void)
> +{
> + MachineState *machine = MACHINE(qdev_get_machine());
> + return machine->config_section;
> +}
> +
> int qemu_loadvm_state(QEMUFile *f)
> {
> MigrationIncomingState *mis = migration_incoming_get_current();
> @@ -1876,15 +1882,18 @@ int qemu_loadvm_state(QEMUFile *f)
> }
>
> if (!savevm_state.skip_configuration) {
> - if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
> + if (qemu_peek_byte(f, 0) == QEMU_VM_CONFIGURATION) {
> + qemu_file_skip(f, 1);
> + ret = vmstate_load_state(f, &vmstate_configuration,
> &savevm_state,
> + 0);
> +
> + if (ret) {
> + return ret;
> + }
> + } else if (must_receive_configuration()) {
> error_report("Configuration section missing");
> return -EINVAL;
> }
> - ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state,
> 0);
> -
> - if (ret) {
> - return ret;
> - }
> }
>
> ret = qemu_loadvm_state_main(f, mis);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 2f0465eeb1d1..10cd64dc266b 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -43,7 +43,8 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
> " aes-key-wrap=on|off controls support for AES key
> wrapping (default=on)\n"
> " dea-key-wrap=on|off controls support for DEA key
> wrapping (default=on)\n"
> " suppress-vmdesc=on|off disables self-describing
> migration (default=off)\n"
> - " nvdimm=on|off controls NVDIMM support (default=off)\n",
> + " nvdimm=on|off controls NVDIMM support (default=off)\n"
> + " config-section=on|off migration requires configuration
> section (default=on)\n",
> QEMU_ARCH_ALL)
> STEXI
> @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
