On Tue, Jul 14, 2020 at 11:22:28AM +0100, Peter Maydell wrote: > On Tue, 14 Jul 2020 at 11:12, Michael S. Tsirkin <m...@redhat.com> wrote: > > And for people who want to build QEMU with lots of functionality (like > > Fedora does), I think a -security flag would be a useful addition. > > We can then tell security researchers "only a high security issue > > if it reproduces with -security=high, only a security issue > > if it reproduces with -security=low". > > I think a -security option would also be useful to users -- it > makes it easier for them to check "is this configuration using > something that I didn't realize was not intended to be secure". > For me, something useful for our users is much more compelling > than "this might make security researchers' lives a bit easier". > > thanks > -- PMM
True. And I guess downstreams can also force the option to high or set the default to high rather easily if they want to. So the option would be: -security level Set minimal required security level of QEMU. high: block use of QEMU functionality which is intended to be secure against malicious guests. low: allow use of all QEMU functionality, best effort security against malicious guests. Default would be -security low. Does this look reasonable? Just a correction to what I wrote: I no longer think it's reasonable to classify the severity of a security issue automatically. E.g. a qemu crash in virtio code is a high severity security issue if it triggers with platform_iommu=on since it is then driver from guest userspace, and low severity one without since then it's driven from a guest driver. So I think we can add something like this to security.rst and to the wiki: only a security issue if it reproduces with -security high, a regular bug if it only reproduces with -security low Prasad? -- MST