Re: [libvirt] [virt-tools-list] [RFC] virt-disk : a command line tool for modify domain XML's disk of inactive domains.

On Mon, 21 Feb 2011 17:27:13 -0700 Eric Blake <eblake(a)redhat.com&gt; wrote: This is a quick hack aginst attach-disk. Seems to work fine for me. But, for example, 'What lock should be held ?' is not very clear to me ;) CC'ed to my co-workers for sharing. Please point out bad things you notice. Total update with detach-disk and attach/detach interfaces will be posted. == From: KAMEZAWA Hiroyuki <kamezawa(a)bluextal.(none)&gt; Date: Tue, 22 Feb 2011 16:09:21 +0900 Subject: [PATCH] This patch is for allowing inactive domain by virsh command. As the first step, this just only supports attach-disk. Further update will allow to support other commands. After this patch, % virsh attach-disk ... --persistent will modify domain XML format of inactive domain. For now, --persistent against active domain returns error. Note: At this stage, I can't guarantee the change will be applied against both of alive guest and its XML definition in atomic. And this is the same behavior Xen driver does. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu(a)jp.fujitsu.com&gt; --- src/qemu/qemu_driver.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 113 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 0f25a2a..80cb724 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -4082,16 +4082,125 @@ cleanup: return ret; } +/* + * Attach a device given by XML, the change will be persistent + * and domain XML definition file is updated. + */ +static int qemuDomainAttachDevicePersistent(virDomainPtr dom, + const char *xml) +{ + struct qemud_driver *driver; + virDomainDeviceDefPtr newdev; + virDomainDefPtr vmdef; + virDomainObjPtr vm; + int i, ret = -1; + int bus_update = -1; + + if ((!dom) || (!dom->conn) || (!dom->name) || (!xml)) { + qemuReportError(VIR_ERR_INVALID_ARG, + _("internal error : %s"), __FUNCTION__); + return -1; + } + + if (dom->conn->flags & VIR_CONNECT_RO) + return -1; + + driver = dom->conn->privateData; + qemuDriverLock(driver); + vm = virDomainFindByUUID(&driver->domains, dom->uuid); + + if (!vm) { + qemuReportError(VIR_ERR_NO_DOMAIN, + _("cannot find domain '%s'"), dom->name); + goto unlock_out; + } + + if (qemuDomainObjBeginJobWithDriver(driver, vm) < 0) + goto unlock_out; + + if (virDomainObjIsActive(vm)) { + /* + * For now, just allow updating inactive domains. Further development + * will allow updating both active domain and its config file at + * the same time. + */ + qemuReportError(VIR_ERR_INVALID_ARG, + _("cannot update alive domain : %s"), __FUNCTION__); + goto endjob; + } + + if (vm->newDef) + vmdef = vm->newDef; + else + vmdef = vm->def; + + newdev = virDomainDeviceDefParse(driver->caps, + vmdef, xml, VIR_DOMAIN_XML_INACTIVE); + if (!newdev) + goto endjob; + /* At first, check device confliction */ + switch(newdev->type) { + case VIR_DOMAIN_DEVICE_DISK: + for (i = 0; i < vmdef->ndisks; i++) { + virDomainDiskDefPtr vdisk; + //virDomainDiskDefPtr vdisk; + vdisk = vm->def->disks[i]; + if (strcmp(vdisk->dst, newdev->data.disk->dst) == 0) { + qemuReportError(VIR_ERR_INVALID_ARG, + _("target %s already exists."), vdisk->dst); + goto endjob; + } + } + if (virDomainDiskInsert(vmdef, newdev->data.disk)) { + virReportOOMError(); + goto endjob; + } + qemuReportError(VIR_ERR_INTERNAL_ERROR, "address info %p", + newdev->data.disk->info); + if (newdev->data.disk->info == NULL) { + /* Auto generate PCI address */ + if (newdev->data.disk->bus == VIR_DOMAIN_DISK_BUS_VIRTIO) + qemuDomainAssignPCIAddresses(vmdef); + /* Other devices as IDE, SCSI...will get ID automatically */ + } + newdev->data.disk = NULL; + break; + default: + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("Sorry, the device is not suppored for now")); + goto endjob; + } + + ret = virDomainSaveConfig(driver->configDir, vmdef); + +endjob: + if (qemuDomainObjEndJob(vm) == 0) + vm = NULL; + if (vm) + virDomainObjUnlock(vm); + /* Note: insert of newdev is done by copy */ + virDomainDeviceDefFree(newdev); +unlock_out: + qemuDriverUnlock(driver); + return ret; +} + static int qemudDomainAttachDeviceFlags(virDomainPtr dom, const char *xml, unsigned int flags) { if (flags & VIR_DOMAIN_DEVICE_MODIFY_CONFIG) { - qemuReportError(VIR_ERR_OPERATION_INVALID, - "%s", _("cannot modify the persistent configuration of a domain")); - return -1; + /* + * Because we can't update the live guest and XML + * in atomic, limiting modification as only-acrive and + * only-inactive. Need some idea to update both at the same time. + */ + return qemuDomainAttachDevicePersistent(dom, xml); } - return qemudDomainAttachDevice(dom, xml); + if (flags & VIR_DOMAIN_DEVICE_MODIFY_LIVE) + return qemudDomainAttachDevice(dom, xml); + + return -1; } -- 1.7.1