PCI: pci-stub module to reserve pci device

When doing device assignment with KVM there's currently nothing to
protect the device from having a driver in the host as well as the guest.
This trivial module just binds the pci device on the host to a stub
driver so that a real host driver can't bind to the device.  It has no
pci id table, it supports only dynamic ids.

 # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
 # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
 # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
 # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
 lrwxrwxrwx 1 root root 0 2008-11-25 19:10 /sys/bus/pci/devices/0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub

Cc: "Kay, Allen M" <allen.m.kay@intel.com>
Cc: "Nakajima, Jun" <jun.nakajima@intel.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index e1ca42591ac4..2a4501dd2515 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -42,6 +42,15 @@ config PCI_DEBUG
 
           When in doubt, say N.
 
+config PCI_STUB
+        tristate "PCI Stub driver"
+        depends on PCI
+        help
+          Say Y or M here if you want be able to reserve a PCI device
+          when it is going to be assigned to a guest operating system.
+
+          When in doubt, say N.
+
 config HT_IRQ
         bool "Interrupts on hypertransport devices"
         default y