[PATCH net-next 1/3] VMCI: only load on VMware hypervisor

[Dexuan Cui]

> From: Dexuan Cui
> Sent: Wednesday, August 16, 2017 15:34
> > From: Jorgen S. Hansen [mailto:jhansen at vmware.com]
> > > Without the patch, vmw_vsock_vmci_transport.ko and vmw_vmci.ko can
> > > automatically load when an application creates an AF_VSOCK socket.
> > >
> > > This is the expected good behavior on VMware hypervisor, but as we
> > > are going to add hv_sock.ko (i.e. Hyper-V transport for AF_VSOCK), we
> > > should make sure vmw_vsock_vmci_transport.ko doesn't load on Hyper-
> V,
> > > otherwise there is a -EBUSY conflict when both
> vmw_vsock_vmci_transport.ko
> > > and hv_sock.ko try to call vsock_core_init() on Hyper-V.
> >
> > The VMCI driver (vmw_vmci.ko) is used both by the VMware guest support
> > (VMware Tools primarily) and by our Workstation product. Always
> disabling the
> > VMCI driver on Hyper-V means that user won’t be able to run Workstation
> > nested in Linux VMs on Hyper-V. Since the VMCI driver itself isn’t the
> problem
> > here, maybe we could move the check to vmw_vsock_vmci_transport.ko?
> > Ideally, there should be some way for a user to have access to both
> protocols,
> > but for now disabling the VMCI socket transport for Hyper-V (possibly with
> a
> > module option to skip that check and always load it) but leaving the VMCI
> driver
> > functional would be better,
> >
> > Jorgen
> 
> Thank you for explaining the background!
> Then I'll make a new patch, following your suggestion.
> 
> -- Dexuan

Hi Jorgen, David,

Just now I posted a new patch
 "[PATCH] vsock: only load vmci transport on VMware hypervisor by default"
to replace this patch.

@Jorgen: 
FWIW, with the new patch, when I create an AF_VSOCK sockets on Hyper-V,
vmw_vmci.ko is also automatically loaded and 3 lines of kernel messages are
printed, but I think I'm OK with this, since it's harmless.

-- Dexuan