On 18/02/2016 12:32, Greg Kurz wrote:
> Migration of pseries-2.3 doesn't have configuration section. Unfortunately,
> QEMU 2.4/2.4.1/2.5 are buggy and always stream and expect the configuration
> section, and break migration both ways.
>
> This patch introduces a property which allows to enforce a configuration
> section for machines who don't have one.
>
> It can be set at startup:
>
> -machine enforce-config-section=on
>
> or later from the QEMU monitor:
>
> qom-set /machine enforce-config-section on
>
> It is up to the tooling to set or unset this property according to the
> version of the QEMU at the other end of the pipe.
>
> Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com>
Reviewed-by: Laurent Vivier <lviv...@redhat.com>
> ---
> hw/core/machine.c | 21 +++++++++++++++++++++
> include/hw/boards.h | 1 +
> migration/savevm.c | 10 ++++++++--
> qemu-options.hx | 3 ++-
> 4 files changed, 32 insertions(+), 3 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 6d1a0d8eebc4..a8c4680b0c47 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -312,6 +312,21 @@ static bool machine_get_suppress_vmdesc(Object *obj,
> Error **errp)
> return ms->suppress_vmdesc;
> }
>
> +static void machine_set_enforce_config_section(Object *obj, bool value,
> + Error **errp)
> +{
> + MachineState *ms = MACHINE(obj);
> +
> + ms->enforce_config_section = value;
> +}
> +
> +static bool machine_get_enforce_config_section(Object *obj, Error **errp)
> +{
> + MachineState *ms = MACHINE(obj);
> +
> + return ms->enforce_config_section;
> +}
> +
> static int error_on_sysbus_device(SysBusDevice *sbdev, void *opaque)
> {
> error_report("Option '-device %s' cannot be handled by this machine",
> @@ -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, "enforce-config-section",
> + machine_get_enforce_config_section,
> + machine_set_enforce_config_section, NULL);
> + object_property_set_description(obj, "enforce-config-section",
> + "Set on to enforce configuration section
> migration",
> + 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..cfdf8d10cfcd 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 enforce_config_section;
>
> ram_addr_t ram_size;
> ram_addr_t maxram_size;
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 94f2894243ce..2fc57363674f 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -878,13 +878,19 @@ bool qemu_savevm_state_blocked(Error **errp)
> return false;
> }
>
> +static bool enforce_config_section(void)
> +{
> + MachineState *machine = MACHINE(qdev_get_machine());
> + return machine->enforce_config_section;
> +}
> +
> void qemu_savevm_state_header(QEMUFile *f)
> {
> trace_savevm_state_header();
> qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
> qemu_put_be32(f, QEMU_VM_FILE_VERSION);
>
> - if (!savevm_state.skip_configuration) {
> + if (!savevm_state.skip_configuration || enforce_config_section()) {
> qemu_put_byte(f, QEMU_VM_CONFIGURATION);
> vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
> }
> @@ -1875,7 +1881,7 @@ int qemu_loadvm_state(QEMUFile *f)
> return -ENOTSUP;
> }
>
> - if (!savevm_state.skip_configuration) {
> + if (!savevm_state.skip_configuration || enforce_config_section()) {
> if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
> error_report("Configuration section missing");
> return -EINVAL;
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 2f0465eeb1d1..8d81e310f2bf 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"
> + " enforce-config-section=on|off enforce configuration
> section migration (default=off)\n",
> QEMU_ARCH_ALL)
> STEXI
> @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
>
