xl: Add pci_assignable_add and remove commands

pci-assignable-add will always store the driver rebind path, but
pci-assignable-remove will only actually rebind if asked to do so.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/docs/man/xl.pod.1 b/docs/man/xl.pod.1
index 2b6e7ac924..e31259b62d 100644
--- a/docs/man/xl.pod.1
+++ b/docs/man/xl.pod.1
@@ -1050,6 +1050,28 @@ These are devices in the system which are configured to be
 available for passthrough and are bound to a suitable PCI
 backend driver in domain 0 rather than a real driver.
 
+=item B<pci-assignable-add> I<BDF>
+
+Make the device at PCI Bus/Device/Function BDF assignable to guests.
+This will bind the device to the pciback driver.  If it is already
+bound to a driver, it will first be unbound, and the original driver
+stored so that it can be re-bound to the same driver later if desired.
+If the device is already bound, it will return success.
+
+CAUTION: This will make the device unusable by Domain 0 until it is
+returned with pci-assignable-remove.  Care should therefore be taken
+not to do this on a device critical to domain 0's operation, such as
+storage controllers, network interfaces, or GPUs that are currently
+being used.
+
+=item B<pci-assignable-remove> [I<-r>] I<BDF>
+
+Make the device at PCI Bus/Device/Function BDF assignable to guests.  This
+will at least unbind the device from pciback.  If the -r option is specified,
+it will also attempt to re-bind the device to its original driver, making it
+usable by Domain 0 again.  If the device is not bound to pciback, it will
+return success.
+
 =item B<pci-attach> I<domain-id> I<BDF>
 
 Hot-plug a new pass-through pci device to the specified domain.