[libvirt] [PATCHv8 1/4] libvirt/qemu - persistent modification of inactive domans.

[KAMEZAWA Hiroyuki]

On Fri, 01 Apr 2011 15:30:13 +0800
Wen Congyang <wency at cn.fujitsu.com> wrote:

> At 04/01/2011 12:17 PM, KAMEZAWA Hiroyuki Write:
> >>From 1ffbe73b1663719414367abbdebc8f31b9592331 Mon Sep 17 00:00:00 2001
> > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> > Date: Thu, 31 Mar 2011 16:20:05 +0900
> > Subject: [PATCHv8 1/4] libvirt/qemu - persistent modification of devices.
> > 
> > Now, qemudDomainAttachDeviceFlags() and qemudDomainDetachDeviceFlags()
> > doesn't support VIR_DOMAIN_DEVICE_MODIFY_CONFIG. By this, virsh's
> > at(de)tatch-device --persistent cannot modify qemu config.
> > (Xen allows it.)
> > 
> > This patch is a base patch for adding support of devices in
> > step by step manner. Following patches will add some device
> > support.
> > 
> > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> > 
> > ---
> >  src/qemu/qemu_driver.c |  150 +++++++++++++++++++++++++++++++++++++++++++-----
> >  1 files changed, 136 insertions(+), 14 deletions(-)
> > 
> > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> > index dd12dc8..b89bc8f 100644
> > --- a/src/qemu/qemu_driver.c
> > +++ b/src/qemu/qemu_driver.c
> > @@ -3873,16 +3873,133 @@ cleanup:
> >      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"));
> > +/*
> > + * At(de)tach a device given by XML, the change will be persistent
> > + * and domain XML definition file is updated when these function
> > + * returns 0(success). IOW, at failure, XML definition is never updated.
> > + * So, this function must guarantee consistency between vmdef and its XML
> > + * definition in the file.
> > + */
> > +
> > +static int qemuDomainAttachDevicePersistent(virDomainDefPtr vmdef,
> > +                                            virDomainDeviceDefPtr newdev)
> > +{
> > +
> > +    switch(newdev->type) {
> > +    default:
> > +        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> > +                        _("the device is not supported for now"));
> >          return -1;
> >      }
> >  
> > -    return qemudDomainAttachDevice(dom, xml);
> > +    return 0;
> > +}
> > +
> > +static int qemuDomainDetachDevicePersistent(virDomainDefPtr vmdef,
> > +                                            virDomainDeviceDefPtr device)
> > +{
> > +    switch(device->type) {
> > +    default:
> > +        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> > +                        _("the device is not supported for now"));
> > +        return -1;
> > +    }
> > +    return 0;
> > +}
> > +
> > +static int qemuDomainModifyDevicePersistent(virDomainPtr dom,
> > +                                            const char *xml,
> > +                                            unsigned int attach,
> > +                                            unsigned int flags)
> > +{
> > +    struct qemud_driver *driver;
> > +    virDomainDeviceDefPtr device;
> > +    virDomainDefPtr vmdef;
> > +    virDomainObjPtr vm;
> > +    int ret = -1;
> > +
> > +    /*
> > +     * When both of MODIFY_CONFIG and MODIFY_LIVE are passed at the same time,
> > +     * return error for now. We should support this later.
> > +     */
> > +    if (flags & VIR_DOMAIN_DEVICE_MODIFY_LIVE) {
> > +        qemuReportError(VIR_ERR_OPERATION_INVALID, "%s",
> > +                        _("cannot modify active domain and its definition "
> > +                          "at the same time."));
> > +        return -1;
> > +    }
> > +
> > +    driver = dom->conn->privateData;
> > +    qemuDriverLock(driver);
> > +    vm = virDomainFindByName(&driver->domains, dom->name);
> > +    if (!vm) {
> > +        qemuReportError(VIR_ERR_NO_DOMAIN, _("no domain with name : '%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_OPERATION_INVALID, "%s",
> > +                        _("cannot modify active domain's definition"));
> > +        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);
> > +    else
> > +        ret = qemuDomainDetachDevicePersistent(vmdef, device);
> > +    /*
> > +     * At(De)tachDevicePersistent() must guarantee that vmdef is consistent
> > +     * with XML definition when they returns a failure, ret != 0.
> > +     */
> 
> This comment can be removed in patch 2 as we use a copy of XML definition.
> 

Hmm, will do when I'll be back. I'll stop update for a week.

Thanks,
-Kame