Re: hook script for changing disk definition before guest start
On 10/21/22 15:30, Gionatan Danti wrote:
Hi all,
due to this [1] I am trying to change a guest's disk definition from
"pool volume" to "file" via hook scripts.
This is downright libvirt bug and needs to be fixed.
For the libvirt developers on CC: when starting a domain, the QEMU
driver sets disk src->path to the actual file path in
virDomainDiskTranslateSourcePool() which is called from
qemuProcessPrepareDomainStorage(). I'm not sure whether the virt-aa
helper sees the translated path in the XML though. So maybe something as
trivial as the following might help?
diff --git i/src/security/virt-aa-helper.c w/src/security/virt-aa-helper.c
index a15971b9bb..f42c3f9a42 100644
--- i/src/security/virt-aa-helper.c
+++ w/src/security/virt-aa-helper.c
@@ -904,6 +904,7 @@ get_files(vahControl * ctl)
#ifdef WITH_STORAGE
virDriverLoadModule("storage", "storageRegister", false);
#endif
+ virDomainDiskTranslateSourcePool(ctl->def);
for (i = 0; i < ctl->def->ndisks; i++) {
virDomainDiskDef *disk = ctl->def->disks[i];
This seems an easy task via virsh detach-disk and virsh attach-disk, but
virsh can not be called inside libvirt hook scripts. The best approach
would be to change the disk definition right when a disk is attached,
but I can not find any event calling a hook script when a disk is
attache/detached.
You don't want to translate the path yourself. Libvirt has extensive
code for that.
Do you have any suggestion short of monitoring the directory
/etc/libvirt/qemu itself for changed files?
Thanks.
These are not the only files where libvirt stores its configuration. For
instance, if I'd 'virsh attach-device --live' then this new device won't
appear in the XML stored under /etc/libvirt/qemu.
I hope we can resolve this libvirt bug soon and you can use fixed
version.
Michal