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

[Dexuan Cui]

> From: David Miller [mailto:davem@xxxxxxxxxxxxx]
> Sent: Wednesday, August 16, 2017 11:07
> 
> From: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Date: Tue, 15 Aug 2017 22:13:29 +0000
> 
> > +	/*
> > +	 * Check if we are running on VMware's hypervisor and bail out
> > +	 * if we are not.
> > +	 */
> > +	if (x86_hyper != &x86_hyper_vmware)
> > +		return -ENODEV;
> 
> This symbol is only available when CONFIG_HYPERVISOR_GUEST is defined.
> But this driver does not have a Kconfig dependency on that symbol so
> the build can fail in some configurations.

Hi David,
It looks typically modern Linux distros have CONFIG_HYPERVISOR_GUEST=y
by default, but I agree here we should make the dependency explicit:

--- a/drivers/misc/vmw_vmci/Kconfig
+++ b/drivers/misc/vmw_vmci/Kconfig
@@ -4,7 +4,7 @@

 config VMWARE_VMCI
        tristate "VMware VMCI Driver"
-       depends on X86 && PCI
+       depends on X86 && PCI && HYPERVISOR_GUEST
        help
          This is VMware's Virtual Machine Communication Interface.  It enables
          high-speed communication between host and guest in a virtual

And it looks it's not a bad thing to add the dependency, because some
existing VMWare drivers have had the dependency on CONFIG_HYPERVISOR_GUEST=y:
drivers/input/mouse/vmmouse.c (MOUSE_PS2_VMMOUSE)
drivers/misc/vmw_balloon.c (VMWARE_BALLOON)

Do you want me to submit a v2 for this patch with the Kconfig change?

-- Dexuan