x86: Unplug emulated disks and nics.

Add a xen_emul_unplug command line option to the kernel to unplug
xen emulated disks and nics.

Set the default value of xen_emul_unplug depending on whether or
not the Xen PV frontends and the Xen platform PCI driver have
been compiled for this kernel (modules or built-in are both OK).

The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM
even if the host platform doesn't support unplug.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index a90172963884..157c93b62dd4 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1314,6 +1314,7 @@ static void __init xen_hvm_guest_init(void)
         if (xen_feature(XENFEAT_hvm_callback_vector))
                 xen_have_vector_callback = 1;
         register_cpu_notifier(&xen_hvm_cpu_notifier);
+        xen_unplug_emulated_devices();
         have_vcpu_info_placement = 0;
         x86_init.irqs.intr_init = xen_init_IRQ;
         xen_hvm_init_time_ops();