This allows to replace the file on a block device and is useful to workaround the cases (migration) when the VM image is placed on some shared storage with exclusive file opening model but the image should be open form more than one app.
The previous version of approaching the workaround was based on the "blockdev-change-medium" command modification but had some flaws: * semantics: blockdev-change-medium is aimed to be used with removable devices only * interface: it can't accept all possible combination of parameters for the "drive" replacement (creation). More details here: http://patchwork.ozlabs.org/patch/1179329/ The current series suggests another approach: 1. blockdev-add 2. qom-set disk.drive = the blockdev added (this is what the series adds) Denis Plotnikov (2): qdev-properties-system: extend set_pionter for unrealized devices block: allow to set 'drive' property on a realized block device hw/core/qdev-properties-system.c | 117 +++++++++++++++++++++++++------ 1 file changed, 96 insertions(+), 21 deletions(-) -- 2.17.0