linux/drivers/xen/xen-pciback
Konrad Rzeszutek Wilk b1df4a56bf xen/pciback: Restore configuration space when detaching from a guest.
The commit "xen/pciback: Don't deadlock when unbinding." was using
the version of pci_reset_function which would lock the device lock.
That is no good as we can dead-lock. As such we swapped to using
the lock-less version and requiring that the callers
of 'pcistub_put_pci_dev' take the device lock. And as such
this bug got exposed.

Using the lock-less version is  OK, except that we tried to
use 'pci_restore_state' after the lock-less version of
__pci_reset_function_locked - which won't work as 'state_saved'
is set to false. Said 'state_saved' is a toggle boolean that
is to be used by the sequence of a) pci_save_state/pci_restore_state
or b) pci_load_and_free_saved_state/pci_restore_state. We don't
want to use a) as the guest might have messed up the PCI
configuration space and we want it to revert to the state
when the PCI device was binded to us. Therefore we pick
b) to restore the configuration space.

We restore from our 'golden' version of PCI configuration space, when an:
 - Device is unbinded from pciback
 - Device is detached from a guest.

Reported-by:  Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:42:02 +00:00
..
conf_space_capability.c xen/pciback: Drop two backends, squash and cleanup some code. 2011-07-19 20:58:35 -04:00
conf_space_header.c xen: Convert printks to pr_<level> 2013-06-28 11:19:58 -04:00
conf_space_quirks.c xen/pciback: miscellaneous adjustments 2011-09-21 18:17:59 -04:00
conf_space_quirks.h xen/pciback: Drop two backends, squash and cleanup some code. 2011-07-19 20:58:35 -04:00
conf_space.c PCI: create common pcibios_err_to_errno 2012-06-12 09:21:42 -06:00
conf_space.h xen/pciback: Drop two backends, squash and cleanup some code. 2011-07-19 20:58:35 -04:00
Makefile xen/pciback: Have 'passthrough' option instead of XEN_PCIDEV_BACKEND_PASS and XEN_PCIDEV_BACKEND_VPCI 2011-07-19 21:04:20 -04:00
passthrough.c xen/pciback: Don't deadlock when unbinding. 2014-12-04 12:41:58 +00:00
pci_stub.c xen/pciback: Restore configuration space when detaching from a guest. 2014-12-04 12:42:02 +00:00
pciback_ops.c arch: Mass conversion of smp_mb__*() 2014-04-18 14:20:48 +02:00
pciback.h xen/pciback: Don't deadlock when unbinding. 2014-12-04 12:41:58 +00:00
vpci.c xen/pciback: Don't deadlock when unbinding. 2014-12-04 12:41:58 +00:00
xenbus.c xen/pciback: Print out the domain owning the device. 2014-12-04 12:42:00 +00:00