Currently we have a bit of a craz setup for activating drivers for virConnectPtr. We iterate over the primary hypervisor drivers until one matches and activates. This bit is fine. Then we do the same for the network, storage, interface, etc secondary drivers. This is where the fun starts. In the case of the stateless drivers that run outside of libvirtd, they always want the secondary drivers to match the primary driver. Unfortunately if they don't register any dummy secondary driver they'll get given the reomte driver instead. The probing of secondary drivers is really unhelpful here. In the case of stateful drivers that run inside of libvirtd, there is (almost) always only one driver instance that they want to work with. So at best the probing of secondary drivers is a waste of time. With the increasing feature set though we're getting tight dependancies from the hypervisor driver to the secondary driver. eg QEMU depends on the specific network driver we have because it calls various internal APIs it exposes. We also have circular dependancy problems during libvirtd startup: https://www.redhat.com/archives/libvir-list/2014-January/msg01143.html There the storage driver needs a virConnectPtr instance in order to talk to the secret driver. At the same time the storage driver must run before the hypervisor driver because the hypervisor driver needs to use it for autostart of VMs. This is a horrible mess. The solution I think is to remove the concept of probing for secondary drivers entirely. Instead I suggest creating a struct virDriver { ... } which contains a pointer to virHypervisorDriver, virNetworkDriver, virInterfaceDriver, etc. now virConnectPtr will only reference the single virDriverPtr and when we open a hypervisor driver, we immediately get a full set of APIs for everything. This way all the hypervisor drivers will always know exactly what secondary driver they are working with. We'll be able to remove all the xxxPrivateData elements from the virConnectPtr. The stateless drivers can just access the main privateData. The stateful drivers can avoid any use of privateData at all - just access their global static variable with the driverState. This won't quite solve the circular dependancy problem in that mail thread above. By removing the directly reliance on the virConnectPtr driver table though, we'll be able to update the code more easily so it can fetch secrets directly and thus the storage driver wont need to do virConnectOpen("qemu:///system"). The patches that follow illustrate the first part of cleaning up use of the xxxPrivateData fields. This isn't complete but I wanted to show the direction it would go before I spend the time todo the full job. Incidentally our code is buggy as hell when it comes to using the xxxPrivateData fields. The PHyp driver actually abuses the networkPrivateData field for all its APIs. Alot of code wil directly access the global state driver state already ignoring the privateData fields already. So they are really more pain than they are worth and leading to buggy code. Daniel P. Berrange (11): Clean up remote driver connection open code Update remote driver to always use privateData Update ESX driver to always use privateData Update Hyper-V driver to always use privateData Move phyp internal info out of the header file Remove abuse of networkPrivateData in phyp driver Update Parallels driver to always use privateData Update Test driver to always use privateData Remove use of storagePrivateData from storage driver Remove use of networkPrivateData from network driver Remove use of networkPrivateData from netcf driver src/esx/esx_device_monitor.c | 6 +- src/esx/esx_interface_driver.c | 16 +- src/esx/esx_network_driver.c | 20 +- src/esx/esx_nwfilter_driver.c | 6 +- src/esx/esx_secret_driver.c | 6 +- src/esx/esx_storage_backend_iscsi.c | 26 +- src/esx/esx_storage_backend_vmfs.c | 36 +-- src/esx/esx_storage_driver.c | 44 ++-- src/hyperv/hyperv_device_monitor.c | 6 +- src/hyperv/hyperv_interface_driver.c | 6 +- src/hyperv/hyperv_network_driver.c | 6 +- src/hyperv/hyperv_nwfilter_driver.c | 6 +- src/hyperv/hyperv_secret_driver.c | 6 +- src/hyperv/hyperv_storage_driver.c | 6 +- src/interface/interface_backend_netcf.c | 71 ++---- src/network/bridge_driver.c | 435 ++++++++++++++------------------ src/parallels/parallels_network.c | 2 - src/parallels/parallels_storage.c | 12 +- src/parallels/parallels_utils.h | 1 + src/phyp/phyp_driver.c | 225 ++++++++--------- src/phyp/phyp_driver.h | 53 ---- src/remote/remote_driver.c | 153 +++-------- src/rpc/gendispatch.pl | 28 +- src/storage/storage_driver.c | 194 +++++++------- src/test/test_driver.c | 24 +- 25 files changed, 537 insertions(+), 857 deletions(-) -- 2.1.0 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
