[virt-tools-list] [RFC] virt-disk : a command line tool for modify domain XML's disk of inactive domains.
KAMEZAWA Hiroyuki
kamezawa.hiroyu at jp.fujitsu.com
Tue Feb 22 07:13:59 UTC 2011
On Mon, 21 Feb 2011 17:27:13 -0700
Eric Blake <eblake at redhat.com> wrote:
> On 02/21/2011 05:20 PM, Eric Blake wrote:
> >> 1. When we asked "Is it a spec that we cannot modify inactive domain ?" to
> >> a Redhat guy, he answered "it's a spec".
> >> Do you, maintainers, have some concensus about this ?
> >
> > 'virsh attach-disk --persistent' is supposed to be able to modify an
> > inactive domain. If it doesn't do so for qemu, then that's because no
> > one has yet implemented it correctly, which means libvirt has a bug that
> > needs to be patched. For example, see:
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=669549
> >
> > about 'virsh setmem --config' not working for qemu.
>
> And https://bugzilla.redhat.com/show_bug.cgi?id=658713 for attach-disk
> --persistent.
>
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 14e1de99d433ba68917a80cc5b82da7f9436d419 Mon Sep 17 00:00:00 2001
From: KAMEZAWA Hiroyuki <kamezawa at bluextal.(none)>
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 at jp.fujitsu.com>
---
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
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