[PATCH v3 0/2] avoid inserting duplicate IDs in dynids list

[Zhenzhong Duan]

vfio-pci and pci-stub use new_id to bind devices. But one can add same IDs
multiple times, for example:

# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/remove_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/remove_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/remove_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/remove_id
-bash: echo: write error: No such device

This doesn't cause user-visible broken behavior, but not user friendly.
he has to remove same IDs same times to ensure it's completely gone.

Changed to only allow one dynamic entry of the same kind, after fix:

# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
-bash: echo: write error: File exists
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/remove_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/remove_id
-bash: echo: write error: No such device


v3: add a separate patch to process dependency issue per Bjorn
    make commit log more clear per Bjorn
v2: revert the export of pci_match_device() per Christoph
    combind PATCH1 and PATCH2 into one.

v2 link:https://lkml.org/lkml/2020/10/25/347

Zhenzhong Duan (2):
  PCI: move pci_match_device() ahead of new_id_store()
  PCI: avoid duplicate IDs in dynamic IDs list

 drivers/pci/pci-driver.c | 146 +++++++++++++++++++++++------------------------
 1 file changed, 73 insertions(+), 73 deletions(-)

-- 
1.8.3.1


Zhenzhong Duan (2):
  PCI: move pci_match_device() ahead of new_id_store()
  PCI: avoid duplicate IDs in dynamic IDs list

 drivers/pci/pci-driver.c | 146 +++++++++++++++++++++++------------------------
 1 file changed, 73 insertions(+), 73 deletions(-)

-- 
1.8.3.1