"Michael S. Tsirkin" [off-list ref] writes:

Please dont' do this, extra indirection hurts performance.
Instead, please change vhost_net_open and scsi to allocate the whole
structure with vmalloc if kmalloc fails, along the lines of
74d332c13b2148ae934ea94dac1745ae92efe8e5

Back in January 2013, you didn't seem to think it was a good idea:

https://lkml.org/lkml/2013/1/23/492