[libvirt] [PATCHv5 1/3] libivrt/qemu - support persistent modification of devices

[Wen Congyang]

At 03/16/2011 02:38 PM, KAMEZAWA Hiroyuki Write:
> Thank you for review and feedbacks. This is v5 onto the latest git tree.
> Any comments are welcome.
> ==
>>From ef85d268a0b553cdb784a1d1916ff8cf171adace Mon Sep 17 00:00:00 2001
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> Date: Wed, 16 Mar 2011 11:35:41 +0900
> Subject: [PATCHv5 1/3] libivrt/qemu - support 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.
> 
> Changelog v4->v5:
>  - fixed error codes at reporting Error.
>  - fixed unlock code after calling qemuDomainObjBeginJobWithDriver()
>  - fixed virDomainFindByUUID() to be virDomainFindByName()
>  - fixed spelling, indent, etc..
>  - removed unnecessary checks.
> 
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> ---
>  src/qemu/qemu_driver.c |  141 +++++++++++++++++++++++++++++++++++++++++++----
>  1 files changed, 129 insertions(+), 12 deletions(-)
> 
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index dac2bf2..dbd5bd3 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -4130,16 +4130,129 @@ cleanup:
>      return ret;
>  }
>  
> -static int qemudDomainAttachDeviceFlags(virDomainPtr dom,
> +/*
> + * 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)
> +{
> +
> +    switch(newdev->type) {
> +    default:
> +        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                        _("Sorry, the device is not supported for now"));
> +        return -1;
> +    }
> +
> +    return 0;
> +}
> +
> +static int qemuDomainDetachDevicePersistent(virDomainDefPtr vmdef,
> +                                            virDomainDeviceDefPtr device)
> +{
> +    switch(device->type) {
> +    default:
> +        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                        _("Sorry, the device is not supported for now"));
> +        return -1;
> +    }
> +    return 0;
> +}
> +
> +static int qemuDomainModifyDevicePersistent(virDomainPtr dom,
>                                          const char *xml,

Indentation is not consistent.

> -                                        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, unsigned int flags)
> +{
> +    struct qemud_driver *driver;
> +    virDomainDeviceDefPtr device;
> +    virDomainDefPtr vmdef;
> +    virDomainObjPtr vm;
> +    int ret = -1;
> +
> +    if (!xml) {
> +        qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("internal error"));
>          return -1;
>      }

xml can not be null, because remoteDomainAttachDevice()/remoteDomainAttachDeviceFlags() will fail
on client when xml is null.

> +    /*
> +     * When both of MODIFY_CONFIG and MODIFY_LIVE is specified 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",
> +                        _("Now, cannot modify alive 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",
> +              _("Now, it's unsupported to update active domain's definition."));

Indentation is not consistent.

> +        goto endjob;
> +    }
> +
> +    vmdef = virDomainObjGetPersistentDef(driver->caps, vm);
> +
> +    if (!vmdef)
> +        goto endjob;
> +
> +    device = virDomainDeviceDefParse(driver->caps,
> +                 vmdef, xml, VIR_DOMAIN_XML_INACTIVE);

Indentation is not consistent.

> +    if (!device)
> +        goto endjob;
> +
> +    if (attach)
> +        ret = qemuDomainAttachDevicePersistent(vmdef, device);
> +    else
> +        ret = qemuDomainDetachDevicePersistent(vmdef, device);
> +
> +    if (!ret) /* save the result */
> +        ret = virDomainSaveConfig(driver->configDir, vmdef);
> +
> +    virDomainDeviceDefFree(device);
> +
> +endjob:
> +    if (qemuDomainObjEndJob(vm) == 0)
> +        vm = NULL;
> +unlock_out:
> +    if (vm)
> +        virDomainObjUnlock(vm);
> +    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, flags);
> +
> +    if (flags & VIR_DOMAIN_DEVICE_MODIFY_LIVE)
> +        return qemudDomainAttachDevice(dom, xml);
> +
> +    qemuReportError(VIR_ERR_INVALID_ARG,
> +        _("bad flag: %x only MODIFY_LIVE, MODIFY_CONFIG are supported now"),

Indentation is not consistent.

> +       flags);
>  
> -    return qemudDomainAttachDevice(dom, xml);
> +    return -1;
>  }
>  
>  
> @@ -4354,13 +4467,17 @@ 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;
> -    }
>  
> -    return qemudDomainDetachDevice(dom, xml);
> +    if (flags & VIR_DOMAIN_DEVICE_MODIFY_CONFIG)
> +        return qemuDomainModifyDevicePersistent(dom, xml, 0, flags);
> +
> +    if (flags & VIR_DOMAIN_DEVICE_MODIFY_LIVE)
> +        return qemudDomainDetachDevice(dom, xml);
> +
> +    qemuReportError(VIR_ERR_INVALID_ARG,
> +        _("bad flag: %x only MODIFY_LIVE, MODIFY_CONFIG are supported now"),

Indentation is not consistent.

> +        flags);
> +    return -1;
>  }
>  
>  static int qemudDomainGetAutostart(virDomainPtr dom,