Aaron Conole <acon...@redhat.com> writes: > Aaron Conole <acon...@redhat.com> writes: > >> This series attempts to introduce the ability to start and use >> Open vSwitch 'out of the box' as a non-root user. It does this by >> modifying the service files to pass the recently introduced --ovs-user >> argument around, and by making some minor tweaks to the passwd, group, >> and filesystem information. >> >> I prefixed the packaging work with 'redhat', but if rpm or packaging >> is a preferred prefx for that work, I can respin. >> >> The more controversial changes are: >> >> * This modifies the /etc/sysconfig/ file on install. >> * The dpdk support directly modifies /dev/hugepages with a call to chmod >> * A new user 'openvswitch', and up to two new groups 'openvswitch', and >> 'hugetlbfs' are created >> * A change to soexpand.pl to allow conditional inclusion of dpdk-related >> options >> > > An interesting development has occurred while testing this series. > > It seems that as part of a rowhammer mitigation, access to > /proc/self/pagemap ends up being restricted. This makes DPDK break in a > catastrophic way. > > One way of mitigating this is to keep the CAP_SYS_ADMIN capability when > DPDK is enabled (not sure whether it would be a runtime or compile > time change). This means we end up keeping many root-user level > permissions that we probably shouldn't need or want. I was thinking > that when DPDK is compiled in, we would keep the CAP_SYS_ADMIN for the > first iteration of DB synchronization, and then drop it after calling > DPDK-init. That would prevent lazy loading, or being able to turn it > on without restarting the daemon (which I don't like). > > Another is to say that if DPDK is enabled at compile time, just don't > drop permissions at all. That approach seems really wrong, but it's a > possibility. > > Not sure what else can be done from the OvS side for this. I think it > could be possible to do something where before dropping privs, we cache > the pagemap and then feed it to DPDK during initialization, but that > will require work from DPDK side, and I'm not sure if it actually works > with DPDK (because I haven't looked into why the pagemap is being read > to begin with). > > So, I'm a bit stuck on this work, and asking for some opinions. >
UPDATE: it seems that with DPDK 17.02+, this has been resolved. I'll wait for resubmit until after the following commit has been applied: https://mail.openvswitch.org/pipermail/ovs-dev/2017-July/334893.html
