[azure][PATCH 06/14] UBUNTU: SAUCE: VMCI: only try to load on VMware hypervisor

[Marcelo Henrique Cerri]

From: Dexuan Cui <decui at microsoft.com>

BugLink: http://bugs.launchpad.net/bugs/1698425

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 adding hv_sock.ko (i.e. Hyper-V transport for AF_VSOCK), we should
make sure vmw_vsock_vmci_transport.ko can'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 the other hand, hv_sock.ko can only load on Hyper-V, because it
depends on hv_vmbus.ko, which deteces Hyper-V in hv_acpi_init().

KVM's vsock_virtio_transport doesn't have the issue because it doesn't
define MODULE_ALIAS_NETPROTO(PF_VSOCK).

Signed-off-by: Dexuan Cui <decui at microsoft.com>
Cc: Alok Kataria <akataria at vmware.com>
Cc: Andy King <acking at vmware.com>
Cc: Adit Ranadive <aditr at vmware.com>
Cc: George Zhang <georgezhang at vmware.com>
Cc: Jorgen Hansen <jhansen at vmware.com>
Cc: K. Y. Srinivasan <kys at microsoft.com>
Cc: Haiyang Zhang <haiyangz at microsoft.com>
Cc: Stephen Hemminger <sthemmin at microsoft.com>
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/misc/vmw_vmci/vmci_driver.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/misc/vmw_vmci/vmci_driver.c b/drivers/misc/vmw_vmci/vmci_driver.c
index d7eaf1eb11e7..1789ea71ff5d 100644
--- a/drivers/misc/vmw_vmci/vmci_driver.c
+++ b/drivers/misc/vmw_vmci/vmci_driver.c
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/hypervisor.h>
 
 #include "vmci_driver.h"
 #include "vmci_event.h"
@@ -58,6 +59,13 @@ static int __init vmci_drv_init(void)
 	int vmci_err;
 	int error;
 
+	/*
+	 * Check if we are running on VMware's hypervisor and bail out
+	 * if we are not.
+	 */
+	if (x86_hyper != &x86_hyper_vmware)
+		return -ENODEV;
+
 	vmci_err = vmci_event_init();
 	if (vmci_err < VMCI_SUCCESS) {
 		pr_err("Failed to initialize VMCIEvent (result=%d)\n",
-- 
2.7.4