Daniel P. Berrange wrote:
>>>> This looks safe, but there's a subtle problem with changing the existing
>>>> virDomainAttachDevice() entry point to call virDomainAttachDeviceFlags().
>>>> It will break compatability with old libvirtd, even though the old
>>>> libvirtd supports the virDomainAttachDevice() code.
>>>>
>> Ah, yes - good catch. Thanks.
>>
>>
>>>> So we need to keep
>>>> the distinct paths in the public API & driver definitions. The eventual
>>>> low level hypervisor drivers can of course just turn their existing
>>>> impl into a thin wrapper to the new method..
>>>>
>>>>
>>> There's one other option actually - we could put compatability code in
>>> the remote driver client instead. Either, make it always invoke the old
>>> RPC call if flags == VIR_DOMAIN_DEVICE_MODIFY_LIVE, or have it invoke
>>> the new RPC call & fallback to the old RPC call if it gets an error
>>> indicating the new one doesn't exist.
>>>
>>>
>> Do you prefer the latter option? After a quick look, I didn't spot any
>> existing compatibility code in the remote driver client. The first
>> option might be slightly better wrt maintenance.
>>
>
> Yes, the first option is certainly simpler / clearer code todo, so lets
> just do that first. We can easily revisit adding compat code in the
> remote driver client at a later date if we find it to be neccessary.
>
Revised patch below.
Thanks,
Jim
commit 487b2434403d520027957ed623354b398984af31
Author: Jim Fehlig <jfehlig@xxxxxxxxxx>
Date: Wed Jan 13 18:34:23 2010 -0700
Public API Implementation
Implementation of public API for virDomain{Attach,Detach}DeviceFlags.
V2: Don't break remote compatibility with older libvirtd
diff --git a/src/libvirt.c b/src/libvirt.c
index 188b991..de802c4 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -5146,14 +5146,68 @@ virDomainAttachDevice(virDomainPtr domain, const char *xml)
conn = domain->conn;
if (conn->driver->domainAttachDevice) {
+ int ret;
+ ret = conn->driver->domainAttachDevice (domain, xml);
+ if (ret < 0)
+ goto error;
+ return ret;
+ }
+
+ virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+ virDispatchError(domain->conn);
+ return -1;
+}
+
+/**
+ * virDomainAttachDeviceFlags:
+ * @domain: pointer to domain object
+ * @xml: pointer to XML description of one device
+ * @flags: an OR'ed set of virDomainDeviceModifyFlags
+ *
+ * Attach a virtual device to a domain, using the flags parameter
+ * to control how the device is attached. VIR_DOMAIN_DEVICE_MODIFY_CURRENT
+ * specifies that the device allocation is made based on current domain
+ * state. VIR_DOMAIN_DEVICE_MODIFY_LIVE specifies that the device shall be
+ * allocated to the active domain instance only and is not added to the
+ * persisted domain configuration. VIR_DOMAIN_DEVICE_MODIFY_CONFIG
+ * specifies that the device shall be allocated to the persisted domain
+ * configuration only. Note that the target hypervisor must return an
+ * error if unable to satisfy flags. E.g. the hypervisor driver will
+ * return failure if LIVE is specified but it only supports modifying the
+ * persisted device allocation.
+ *
+ * Returns 0 in case of success, -1 in case of failure.
+ */
+int
+virDomainAttachDeviceFlags(virDomainPtr domain,
+ const char *xml, unsigned int flags)
+{
+ virConnectPtr conn;
+ DEBUG("domain=%p, xml=%s, flags=%d", domain, xml, flags);
+
+ virResetLastError();
+
+ if (!VIR_IS_CONNECTED_DOMAIN(domain)) {
+ virLibDomainError(NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+ return (-1);
+ }
+ if (domain->conn->flags & VIR_CONNECT_RO) {
+ virLibDomainError(domain, VIR_ERR_OPERATION_DENIED, __FUNCTION__);
+ goto error;
+ }
+ conn = domain->conn;
+
+ if (conn->driver->domainAttachDeviceFlags) {
int ret;
- ret = conn->driver->domainAttachDevice (domain, xml);
+ ret = conn->driver->domainAttachDeviceFlags(domain, xml, flags);
if (ret < 0)
goto error;
return ret;
}
- virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+ virLibConnError(conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
error:
virDispatchError(domain->conn);
@@ -5192,12 +5246,66 @@ virDomainDetachDevice(virDomainPtr domain, const char *xml)
if (conn->driver->domainDetachDevice) {
int ret;
ret = conn->driver->domainDetachDevice (domain, xml);
+ if (ret < 0)
+ goto error;
+ return ret;
+ }
+
+ virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+ virDispatchError(domain->conn);
+ return -1;
+}
+
+/**
+ * virDomainDetachDeviceFlags:
+ * @domain: pointer to domain object
+ * @xml: pointer to XML description of one device
+ * @flags: an OR'ed set of virDomainDeviceModifyFlags
+ *
+ * Detach a virtual device from a domain, using the flags parameter
+ * to control how the device is detached. VIR_DOMAIN_DEVICE_MODIFY_CURRENT
+ * specifies that the device allocation is removed based on current domain
+ * state. VIR_DOMAIN_DEVICE_MODIFY_LIVE specifies that the device shall be
+ * deallocated from the active domain instance only and is not from the
+ * persisted domain configuration. VIR_DOMAIN_DEVICE_MODIFY_CONFIG
+ * specifies that the device shall be deallocated from the persisted domain
+ * configuration only. Note that the target hypervisor must return an
+ * error if unable to satisfy flags. E.g. the hypervisor driver will
+ * return failure if LIVE is specified but it only supports removing the
+ * persisted device allocation.
+ *
+ * Returns 0 in case of success, -1 in case of failure.
+ */
+int
+virDomainDetachDeviceFlags(virDomainPtr domain,
+ const char *xml, unsigned int flags)
+{
+ virConnectPtr conn;
+ DEBUG("domain=%p, xml=%s, flags=%d", domain, xml, flags);
+
+ virResetLastError();
+
+ if (!VIR_IS_CONNECTED_DOMAIN(domain)) {
+ virLibDomainError(NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+ return (-1);
+ }
+ if (domain->conn->flags & VIR_CONNECT_RO) {
+ virLibDomainError(domain, VIR_ERR_OPERATION_DENIED, __FUNCTION__);
+ goto error;
+ }
+ conn = domain->conn;
+
+ if (conn->driver->domainDetachDeviceFlags) {
+ int ret;
+ ret = conn->driver->domainDetachDeviceFlags(domain, xml, flags);
if (ret < 0)
goto error;
return ret;
}
- virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+ virLibConnError(conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
error:
virDispatchError(domain->conn);
--
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