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Add a vmstate subsection to SCSIDiskState so that scsi-block devices can transfer their reservation state during live migration. Upon loading the subsection, the destination QEMU invokes the PERSISTENT RESERVE OUT command's PREEMPT service action to atomically move the reservation from the source I_T nexus to the destination I_T nexus. This results in transparent live migration of SCSI reservations. This approach is incomplete since SCSI reservations are cooperative and other hosts could interfere. Neither the source QEMU nor the destination QEMU are aware of changes made by other hosts. The assumption is that reservation is not taken over by a third host without cooperation from the source host. I considered adding the vmstate subsection to SCSIDevice instead of SCSIDiskState, since reservations are part of the SCSI Primary Commands that other devices apart from disks could support. However, due to fragility of migrating reservations, we will probably limit support to scsi-block and maybe scsi-disk in the future. In the end, I think it makes sense to place this within scsi-disk.c. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20260129212035.219676-5-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>