On 06/03/2025 15.10, shalini wrote:
On 2025-03-05 19:33, Thomas Huth wrote:On 24/02/2025 13.04, Shalini Chellathurai Saroja wrote:Register Control-Program Identification data with the live migration infrastructure.Signed-off-by: Shalini Chellathurai Saroja <shal...@linux.ibm.com> Reviewed-by: Nina Schoetterl-Glausch <n...@linux.ibm.com> --- hw/s390x/s390-virtio-ccw.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index 13ea8db1b0..4d0838d037 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -260,6 +260,20 @@ static void s390_create_sclpconsole(SCLPDevice *sclp, qdev_realize_and_unref(dev, ev_fac_bus, &error_fatal); } +static const VMStateDescription vmstate_control_program_id = { + .name = "s390_control_program_id", + .version_id = 0, + .minimum_version_id = 0, + .fields = (const VMStateField[]) { + VMSTATE_UINT8_ARRAY(system_type, ControlProgramId, 8), + VMSTATE_UINT8_ARRAY(system_name, ControlProgramId, 8), + VMSTATE_UINT64(system_level, ControlProgramId), + VMSTATE_UINT8_ARRAY(sysplex_name, ControlProgramId, 8), + VMSTATE_UINT64(timestamp, ControlProgramId), + VMSTATE_END_OF_LIST() + } +}; + static void ccw_init(MachineState *machine) { MachineClass *mc = MACHINE_GET_CLASS(machine); @@ -308,6 +322,9 @@ static void ccw_init(MachineState *machine) ret = css_create_css_image(VIRTUAL_CSSID, true); assert(ret == 0); + /* register CPI values */ + vmstate_register_any(NULL, &vmstate_control_program_id, &ms->cpi);Hi again, after looking at this for a while, I think it might be cleaner to store the state in the TYPE_SCLP_CPI device instead of storing it in the machine state. Then you can also use dc->vmsd there instead of using the legacy vmstate_register_any() function.Hello Thomas,The SCLP event type CPI is used to transfer the data mentioned below from guest operating system to QEMU. The job of the CPI event is complete, when this transfer is done.The received data must be saved in the QEMU object model, so that it is possible for the user to retrieve the data via QMP. The received data provides information about the guest virtual machine.System type - Operating system of the guest (eg: LINUX) System name - Hostname provided to the guest (eg: TESTVM) System level - Kernel version of the guest operating system (eg: 0x50e00)Sysplex name - Sysplex refers to a cluster of logical partitions that communicates and co-operates with each other. Sysplex name is the name of the cluster which the guest belongs to(If any).(eg: PLEX)In my perspective, I believe that the s390 machine state is appropriate for storing the data about the guest virtual machine. Please do let me know if you still want to change this?, thank you.
Hi Shalini,yes, please change this patch to put the migration state into the SCLP_CPI device.
vmstate_register_any() is a legacy function, see its description in include/migration/vmstate.h ... so if anyhow possible, this should be avoided in new code.
You introduced a new device in patch 2 which will be handling the related data. Devices are the right place for storing migration data in new QEMU code, so I think this really should go into dc->vmsd of TYPE_SCLP_CPI.
For retrieving the information, the user should then just get the property from /machine/sclp/s390-sclp-event-facility/sclpcpi instead of /machine. This should be fine since it is a well-defined location, too.
Thanks! Thomas
