Re: [libvirt] [PATCH v2] Perform disk config validity checking for attach-device config

https://bugzilla.redhat.com/show_bug.cgi?id=1078126 Using 'virsh attach-device --config' (or --persistent) to attach a file backed lun device will succeed; however, subsequent domain restarts will result in failure because the configuration of a file backed lun is not supported. Although allowing 'illegal configurations' is something that can be allowed, it may not be practical in this case. Generally, when attaching a device to a domain means the domain must be running. A way around this is using the --config (or --persistent) option. When an attach is done to a running domain, a temporary configuration is modified first followed by the live update. The live update will make a number of disk validity checks when building the qemu command to attach the disk. If any fail, then change is rejected. Rather than allow a potentially illegal combination, adjust the code in the configuration path to make the same checks as the running path will make with respect to disk validity checks. This way we avoid having the potential for some subsequent start/reboot to fail because an illegal combination was allowed. NB: The live path still checks the configuration since it is possible to just do --live guest modification... Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- Changes since V1: http://www.redhat.com/archives/libvir-list/2014-August/msg00045.html Based on #virt IRC discussion this morning - move the qemu_caps checking to only occur during the live check - slightly change the name of the called routine src/qemu/qemu_command.c | 127 +++++++++++++++++++++++++++--------------------- src/qemu/qemu_command.h | 2 + src/qemu/qemu_driver.c | 2 + 3 files changed, 76 insertions(+), 55 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 033a5a8..c1791d9 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3230,6 +3230,73 @@ qemuGetDriveSourceString(virStorageSourcePtr src, } +/* Perform disk definition config validity checks */ +int +qemuBuildCheckDiskConfig(virDomainDiskDefPtr disk)