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/xen-ops.h b/arch/x86/xen/xen-ops.h
index 089d18923d2b..ed776949024c 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -40,6 +40,7 @@ void xen_vcpu_restore(void);
 
 void xen_callback_vector(void);
 void xen_hvm_init_shared_info(void);
+void __init xen_unplug_emulated_devices(void);
 
 void __init xen_build_dynamic_phys_to_machine(void);