On Thu, Feb 24, 2011 at 01:06:36PM +0900, KAMEZAWA Hiroyuki wrote:
> >From d6c65102224c493f67008b6521b0115d798f5a67 Mon Sep 17 00:00:00 2001
> From: KAMEZAWA Hiroyuki <kamezawa@bluextal.(none)>
> Date: Thu, 24 Feb 2011 12:14:25 +0900
> Subject: [PATCH 1/2] libvirt/qemu - support updating inactive domains.
>
> Now, virsh attach-disk/detach-disk has --persistent option and
> it can update XML definition of inactive domains. But, it's only
> supported in Xen.
>
> This patch adds support for attach-disk/detach-disk for qemu.
>
> Changelog v1->v2:
> - fixed TABs
> - fixed PCI address assignment for VIRTIO driver.
>
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> ---
> src/qemu/qemu_driver.c | 168 +++++++++++++++++++++++++++++++++++++++++++++---
> 1 files changed, 158 insertions(+), 10 deletions(-)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 8b15a3e..e75478a 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -4085,14 +4085,164 @@ cleanup:
> return ret;
> }
>
> -static int qemudDomainAttachDeviceFlags(virDomainPtr dom,
> +static int qemuDomainFindDiskByName(virDomainDefPtr vmdef, const char *name)
> +{
> + virDomainDiskDefPtr vdisk;
> + int i;
> +
> + for (i = 0; i < vmdef->ndisks; i++) {
> + vdisk = vmdef->disks[i];
> + if (!strcmp(vdisk->dst, name))
Maybe STREQ() is better here as other libvirt code uses STREQ() rather
than strcmp().
> + return i;
> + }
> + return -1;
> +}
> +/*
> + * Attach a device given by XML, the change will be persistent
> + * and domain XML definition file is updated.
> + */
> +static int qemuDomainAttachDevicePersistent(virDomainDefPtr vmdef,
> + virDomainDeviceDefPtr newdev)
> +{
> + virDomainDiskDefPtr disk;
> +
> + /* At first, check device confliction */
> + switch(newdev->type) {
> + case VIR_DOMAIN_DEVICE_DISK:
> + disk = newdev->data.disk;
> + if (qemuDomainFindDiskByName(vmdef, disk->dst) >= 0) {
> + qemuReportError(VIR_ERR_INVALID_ARG,
> + _("target %s already exists."), disk->dst);
> + return -1;
> + }
> +
> + if (virDomainDiskInsert(vmdef, disk)) {
> + virReportOOMError();
I think it's better to report OOM error by virDomainDiskInsert() itself,
otherwise every caller has to call virReportOOMError() when fails.
> + return -1;
> + }
> + if (disk->bus == VIR_DOMAIN_DISK_BUS_VIRTIO) {
> + /*
> + * Address/Drive information is NULL. If virtio, PCI address
> + * shoule be fixed. Other devices as IDE, SCSI...will get ID
> + * automatically
> + */
> + qemuDomainAssignPCIAddresses(vmdef);
> +
> + }
> + newdev->data.disk = NULL;
> + break;
> + default:
> + qemuReportError(VIR_ERR_INVALID_ARG, "%s",
> + _("Sorry, the device is not suppored for now"));
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +static int qemuDomainDetachDevicePersistent(virDomainDefPtr vmdef,
> + virDomainDeviceDefPtr device)
> +{
> + int x;
> + virDomainDiskDefPtr disk;
> +
> + switch(device->type) {
> + case VIR_DOMAIN_DEVICE_DISK:
> + disk = device->data.disk;
> + x = qemuDomainFindDiskByName(vmdef, disk->dst);
> + if (x < 0) {
> + qemuReportError(VIR_ERR_INVALID_ARG,
> + _("target %s doesn't exist."), disk->dst);
> + return -1;
> + }
> + virDomainDiskRemove(vmdef, x);
> + break;
> + default:
> + qemuReportError(VIR_ERR_INVALID_ARG, "%s",
> + _("Sorry, the device is not suppored for now"));
> + return -1;
> + }
> + return 0;
> +}
> +
> +static int qemuDomainModifyDevicePersistent(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"));
> + unsigned int attach)
> +{
> + struct qemud_driver *driver;
> + virDomainDeviceDefPtr device;
> + virDomainDefPtr vmdef;
> + virDomainObjPtr vm;
> + int ret = -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;
No need to check the RO flag here: it should be and is done in
virDomainAttachDevice().
> +
> + 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) {
> + /*
> + * 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__);
I think we can silently fail here. Currently this function (qemuDomainModifyDevicePersistent)
is called only for modifying inactive domains.
> + goto endjob;
> + }
> + vmdef = virDomainObjGetPersistentDef(driver->caps, vm);
> +
> + if (!vmdef)
> + goto endjob;
> +
> + device = virDomainDeviceDefParse(driver->caps,
> + vmdef, xml, VIR_DOMAIN_XML_INACTIVE);
> + if (!device)
> + goto endjob;
> +
> + if (attach) {
> + ret = qemuDomainAttachDevicePersistent(vmdef, device);
> + if (ret < 0)
> + goto out;
> + } else {
> + ret = qemuDomainDetachDevicePersistent(vmdef, device);
> + if (ret < 0)
> + goto out;
> }
This can be refined as:
if (attach)
ret = qemuDomainAttachDevicePersistent(vmdef, device);
else
ret = qemuDomainDetachDevicePersistent(vmdef, device);
if (ret < 0)
goto out;
> + ret = virDomainSaveConfig(driver->configDir, vmdef);
> +
> +out:
> + virDomainDeviceDefFree(device);
> +endjob:
> + if (qemuDomainObjEndJob(vm) == 0)
> + vm = NULL;
> + if (vm)
> + virDomainObjUnlock(vm);
> + /* Note: insert of newdev is done by copy */
> +unlock_out:
> + qemuDriverUnlock(driver);
> + return ret;
> +}
> +
> +static int qemudDomainAttachDeviceFlags(virDomainPtr dom,
> + const char *xml,
> + unsigned int flags) {
> +
> + if (flags & VIR_DOMAIN_DEVICE_MODIFY_CONFIG)
> + return qemuDomainModifyDevicePersistent(dom, xml, 1);
>
> return qemudDomainAttachDevice(dom, xml);
> }
> @@ -4306,11 +4456,9 @@ cleanup:
> static int qemudDomainDetachDeviceFlags(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;
> - }
> +
> + if (flags & VIR_DOMAIN_DEVICE_MODIFY_CONFIG)
> + return qemuDomainModifyDevicePersistent(dom, xml, 0);
>
> return qemudDomainDetachDevice(dom, xml);
> }
> --
> 1.7.1
--
Thanks,
Hu Tao
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