Re: [libvirt] [PATCH 5/5] qemu: hook: Provide hook when restoring a domain save image

--- docs/hooks.html.in | 11 ++++++++ src/qemu/qemu_driver.c | 69 +++++++++++++++++++++++++++++++++++++++++++++----- src/util/virhook.c | 3 ++- src/util/virhook.h | 1 + 4 files changed, 76 insertions(+), 8 deletions(-) diff --git a/docs/hooks.html.in b/docs/hooks.html.in index 07b9d49..265dbb7 100644 --- a/docs/hooks.html.in +++ b/docs/hooks.html.in @@ -177,6 +177,17 @@ script returns failure or the output XML is not valid, incoming migration will be canceled. This hook may be used, e.g., to change location of disk images for incoming domains.</li> + <li><span class="since">Since 1.2.9</span>, the qemu hook script is + also called when restoring a saved image either via the API or + automatically when restoring a managed save machine. It is called + as: <pre>/etc/libvirt/hooks/qemu guest_name restore begin -</pre> + with domain XML sent to standard input of the script. In this case, + the script acts as a filter and is supposed to modify the domain + XML and print it out on its standard output. Empty output is + identical to copying the input XML without changing it. In case the + script returns failure or the output XML is not valid, restore of the + image will be aborted. This hook may be used, e.g., to change + location of disk images for incoming domains.</li>

<li><span class="since">Since 0.9.13</span>, the qemu hook script is also called when the libvirtd daemon restarts and reconnects to previously running QEMU processes. If the script fails, the diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 1d82e93..2dd2e48 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5636,20 +5636,23 @@ qemuDomainRestoreFlags(virConnectPtr conn, unsigned int flags) { virQEMUDriverPtr driver = conn->privateData; + qemuDomainObjPrivatePtr priv = NULL; virDomainDefPtr def = NULL; - virDomainDefPtr newdef = NULL; virDomainObjPtr vm = NULL; + char *xml = NULL; + char *xmlout = NULL; int fd = -1; int ret = -1; virQEMUSaveHeader header; virFileWrapperFdPtr wrapperFd = NULL; + bool hook_taint = false; virCheckFlags(VIR_DOMAIN_SAVE_BYPASS_CACHE | VIR_DOMAIN_SAVE_RUNNING | VIR_DOMAIN_SAVE_PAUSED, -1); - fd = qemuDomainSaveImageOpen(driver, path, &def, &header, NULL, + fd = qemuDomainSaveImageOpen(driver, path, &def, &header, &xml, (flags & VIR_DOMAIN_SAVE_BYPASS_CACHE) != 0, &wrapperFd, false, false); if (fd < 0) @@ -5658,12 +5661,29 @@ qemuDomainRestoreFlags(virConnectPtr conn, if (virDomainRestoreFlagsEnsureACL(conn, def) < 0) goto cleanup; - if (dxml) { - if (!(newdef = qemuDomainSaveImageUpdateDef(driver, def, dxml))) + if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) { + int hookret; + + if ((hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, def->name, + VIR_HOOK_QEMU_OP_RESTORE, + VIR_HOOK_SUBOP_BEGIN, + NULL, + dxml ? dxml : xml, + &xmlout)) < 0) goto cleanup; - virDomainDefFree(def); - def = newdef; + if (hookret == 0 && xmlout) { + virDomainDefPtr tmp; + + VIR_DEBUG("Using hook-filtered domain XML: %s", xmlout); + + if (!(tmp = qemuDomainSaveImageUpdateDef(driver, def, xmlout))) + goto cleanup; + + virDomainDefFree(def); + def = tmp; + hook_taint = true; + }

} if (!(vm = virDomainObjListAdd(driver->domains, def,