On Mon, Mar 06, 2023 at 09:03:42AM +0000, Daniel P. Berrangé wrote: > On Fri, Mar 03, 2023 at 07:46:27PM -0500, Laine Stump wrote: > > On 3/3/23 1:36 PM, Daniel P. Berrangé wrote: > > > On Fri, Mar 03, 2023 at 10:18:39AM -0800, Andrea Bolognani wrote: > > > > I still don't understand why we can't simply execute passt and let > > > > the domain transition defined in the policy take care of switching to > > > > the appropriate label from us, like we do for dnsmasq and other > > > > tools? Why do we need to do things differently for passt? > > > > > > That won't get the per-VM label applied. It will end up running > > > passt_t:s0:c0.c1023, but we want it to be passt_t:s0:c342,155. > > > To transition from non-MCS to MCS, you have to explicitly tell > > > the kernel what to do instead of relying on the plain automatic > > > transition. > > > > Since you've brought up dnsmasq as an example, note that the dnsmasq > > processes don't have any MCS (which I guess is the right thing, since a > > single dnsmasq might be used by many/any/all guests, contrasting with passt, > > or the slirp-helper or tpm, which have one instance per guest device. This > > does make dnsmasq a "not ideal" example when figuring out what is needed for > > passt though (in some ways, but not others)(I think? I still can't claim to > > fully grok all the details of this). > > Yes, you are correct. > > dbus/slirp/swtpm are better matches for the passt scenario, though they > are also not useful examples since we've ignored the SELinux labeling > needs in all of them, so they all undermine svirt if used. Got it! The MCS bit is indeed the part that I had been missing. -- Andrea Bolognani / Red Hat / Virtualization
