On Thu, Jan 08, 2015 at 11:59:09AM +0000, Marc Zyngier wrote: > When handling a fault in stage-2, we need to resync I$ and D$, just > to be sure we don't leave any old cache line behind. > > That's very good, except that we do so using the *user* address. > Under heavy load (swapping like crazy), we may end up in a situation > where the page gets mapped in stage-2 while being unmapped from > userspace by another CPU. > > At that point, the DC/IC instructions can generate a fault, which > we handle with kvm->mmu_lock held. The box quickly deadlocks, user > is unhappy. > > Instead, perform this invalidation through the kernel mapping, > which is guaranteed to be present. The box is much happier, and so > am I. > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> This looks good to me! Thanks, -Christoffer -- 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
