On Thu, Oct 1, 2015 at 12:15 AM, Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > * Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > >> > These could still be open coded in an inlined fashion, like the scheduler usage. >> >> We could have a raw_rdmsr for those. >> >> OTOH, I'm still not 100% convinced that this warn-but-don't-die behavior is >> worth the effort. This isn't a frequent source of bugs to my knowledge, and we >> don't try to recover from incorrect cr writes, out-of-bounds MMIO, etc, so do we >> really gain much by rigging a recovery mechanism for rdmsr and wrmsr failures >> for code that doesn't use the _safe variants? > > It's just the general principle really: don't crash the kernel on bootup. There's > few things more user hostile than that. > > Also, this would maintain the status quo: since we now (accidentally) don't crash > the kernel on distro kernels (but silently and unsafely ignore the faulting > instruction), we should not regress that behavior (by adding the chance to crash > again), but improve upon it. Just a heads up: the extable improvements in tip:ras/core make it straightforward to get the best of all worlds: explicit failure handling (written in C!), no fast path overhead whatsoever, and no new garbage in the exception handlers. Patches coming once I test them. > > Thanks, > > Ingo -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
