tree 7a423a099af084c3bf81ea9c3ffe13ea22e18821
parent 1dd6af7395670f3dcd05ddb64ce6c374a81ae701
author Igor Druzhinin <igor.druzhinin@citrix.com> 1523976855 +0100
committer Stefano Stabellini <sstabellini@kernel.org> 1526666512 -0700

xen/pt: use address_space_memory object for memory region hooks

Commit 99605175c (xen-pt: Fix PCI devices re-attach failed) introduced
a subtle bug. As soon as the guest switches off Bus Mastering on the
device it immediately causes all the BARs be unmapped due to the DMA
address space of the device being changed. This is undesired behavior
because the guest may try to communicate with the device after that
which triggers the following errors in the logs:

[00:05.0] xen_pt_bar_read: Error: Should not read BAR through QEMU. @0x0000000000000200
[00:05.0] xen_pt_bar_write: Error: Should not write BAR through QEMU. @0x0000000000000200

The issue that the original patch tried to workaround (uneven number of
region_add/del calls on device attach/detach) was fixed in d25836cafd
(memory: do explicit cleanup when remove listeners).

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>