Re: [libvirt] [PATCH 09/14] qemu: Start PR daemons on domain startup

On Thu, Jan 18, 2018 at 17:04:41 +0100, Michal Privoznik wrote: > Before we exec() qemu we have to spawn pr-helper processes for > all managed reservations (well, technically there can only one). > The only caveat there is that we should place the process into > the same namespace and cgroup as qemu (so that it shares the same > view of the system). But we can do that only after we've forked. > That means calling the setup function between fork() and exec(). > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > src/qemu/qemu_process.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 151 insertions(+) > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c > index 25ec464d3..02608c1f3 100644 > --- a/src/qemu/qemu_process.c > +++ b/src/qemu/qemu_process.c > @@ -2507,6 +2507,151 @@ qemuProcessSetupEmulator(virDomainObjPtr vm) > } > > > +static int > +qemuProcessSetupOnePRDaemonHook(void *opaque) > +{ > + virDomainObjPtr vm = opaque; > + size_t i, nfds = 0; > + int *fds = NULL; > + int ret = -1; > + > + if (virProcessGetNamespaces(vm->pid, &nfds, &fds) < 0) If this detects '0' namespaces ... > + return ret; > + > + if (virProcessSetNamespaces(nfds, fds) < 0) ... this call will be unhappy.