> > > > > > > > Access to pci config space is explictly checked with CAP_SYS_ADMIN > > > > in order to read configuration space past the frist 64B. > > > > > > > > Since the path is only for reading, could we use CAP_SYS_RAWIO? > > > > > > Why? What needs this reduced capability? > > > > Thanks for the review. > > > > We need read access to /sys/bus/pci/devices/, We need write access to > > config, > > remove, rescan & enable files under the device directory for each PCIe > > functions & the downstream PCIe port. > > > > We need r/w access to sysfs to unbind and rebind the root complex. > > That didn't answer my question at all.
Sorry about that, breaking it down: When the machine first boots, the VFIO device bindings under /dev/vfio are not present. root@localhost:/tmp# ls -l /dev/vfio/ total 0 crw-rw-rw-. 1 root root 10, 196 Jan 5 01:47 vfio We have an agent which needs to run the following commands (We get access denied here and need permissions to do this). echo -n xxxx yyyy > /sys/module/vfio_pci/drivers/pci:vfio-pci/new_id echo -n xxxx yyyy > /sys/module/vfio_pci/drivers/pci:vfio-pci/new_id And we want to avoid handing CAP_SYS_ADMIN here. Which is why the thought about CAP_SYS_RAWIO. > > Why can't you have the process that wants to do all of the above, have > admin rights as well? Doing all of that is _very_ low-level and can > cause all sorts of horrible things to happen to your machine, and is not > really "raw io" in the traditional sense at all, right? If the above approach is going to cause the system to do horrible things, then I'll drop the idea. -- - Allen