[PATCH 02/11] hyperv: implement domainUndefine and domainUndefineFlags

[Daniel P. Berrangé]

On Tue, Nov 24, 2020 at 02:48:31PM -0500, Matt Coleman wrote:
> Co-authored-by: Sri Ramanujam <sramanujam at datto.com>
> Signed-off-by: Matt Coleman <matt at datto.com>
> ---
>  src/hyperv/hyperv_driver.c | 60 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 60 insertions(+)
> 
> diff --git a/src/hyperv/hyperv_driver.c b/src/hyperv/hyperv_driver.c
> index 6d81deb4d9..8e16ff529f 100644
> --- a/src/hyperv/hyperv_driver.c
> +++ b/src/hyperv/hyperv_driver.c
> @@ -1874,6 +1874,64 @@ hypervDomainCreate(virDomainPtr domain)
>  }
>  
>  
> +static int
> +hypervDomainUndefineFlags(virDomainPtr domain, unsigned int flags)
> +{
> +    int result = -1;
> +    char uuid_string[VIR_UUID_STRING_BUFLEN];
> +    hypervPrivate *priv = domain->conn->privateData;
> +    Msvm_ComputerSystem *computerSystem = NULL;
> +    g_autoptr(hypervInvokeParamsList) params = NULL;
> +    g_auto(virBuffer) eprQuery = VIR_BUFFER_INITIALIZER;
> +
> +    virCheckFlags(0, -1);
> +
> +    virUUIDFormat(domain->uuid, uuid_string);
> +
> +    if (hypervMsvmComputerSystemFromDomain(domain, &computerSystem) < 0)
> +        goto cleanup;
> +
> +    /* try to shut down the VM if it's not disabled, just to be safe */
> +    if (computerSystem->data->EnabledState != MSVM_COMPUTERSYSTEM_ENABLEDSTATE_DISABLED &&
> +        hypervDomainShutdown(domain) < 0) {
> +        goto cleanup;
> +    }

Many, but not all, drivers in libvirt allow undefining the cofig for a running
VM. ie we can delete the config on disk, without affecting the running VM.
This results in a so called "transient" VM - basically a VM which only exists
as long as it is running - virDomainCreateXML creates such a beast, while
virDomainDefineXML+virDomainCreate  creates a "persistent" VM and starts it.

If hyperv doesn't allow that, then shutting down the VM is likely to be
surprising.

I'd suggest we report an error indicating undefine is not permitted for a
running VM in such a case.


> +
> +    /* prepare params */
> +    params = hypervCreateInvokeParamsList("DestroySystem",
> +                                          MSVM_VIRTUALSYSTEMMANAGEMENTSERVICE_SELECTOR,
> +                                          Msvm_VirtualSystemManagementService_WmiInfo);
> +
> +    if (!params)
> +        goto cleanup;
> +
> +    virBufferEscapeSQL(&eprQuery,
> +                       MSVM_COMPUTERSYSTEM_WQL_SELECT "WHERE Name = '%s'",
> +                       uuid_string);
> +
> +    if (hypervAddEprParam(params, "AffectedSystem", &eprQuery, Msvm_ComputerSystem_WmiInfo) < 0)
> +        goto cleanup;
> +
> +    /* actually destroy the VM */
> +    if (hypervInvokeMethod(priv, &params, NULL) < 0)
> +        goto cleanup;
> +
> +    result = 0;
> +
> + cleanup:
> +    hypervFreeObject(priv, (hypervObject *)computerSystem);
> +
> +    return result;
> +}
> +
> +
> +static int
> +hypervDomainUndefine(virDomainPtr domain)
> +{
> +    return hypervDomainUndefineFlags(domain, 0);
> +}
> +
> +
>  static int
>  hypervDomainGetAutostart(virDomainPtr domain, int *autostart)
>  {
> @@ -2485,6 +2543,8 @@ static virHypervisorDriver hypervHypervisorDriver = {
>      .connectNumOfDefinedDomains = hypervConnectNumOfDefinedDomains, /* 0.9.5 */
>      .domainCreate = hypervDomainCreate, /* 0.9.5 */
>      .domainCreateWithFlags = hypervDomainCreateWithFlags, /* 0.9.5 */
> +    .domainUndefine = hypervDomainUndefine, /* 6.10.0 */
> +    .domainUndefineFlags = hypervDomainUndefineFlags, /* 6.10.0 */
>      .domainGetAutostart = hypervDomainGetAutostart, /* 6.9.0 */
>      .domainSetAutostart = hypervDomainSetAutostart, /* 6.9.0 */
>      .domainGetSchedulerType = hypervDomainGetSchedulerType, /* 6.10.0 */
> -- 
> 2.27.0
> 
> 

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|