Re: [libvirt] [PATCH 4/9] Public API Implementation

>>> 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.