On Thu, Jun 30, 2016 at 06:40:33PM +0100, Marc Zyngier wrote: > Until now, we've been setting up KVM using two sets of page tables: > one for the "boot" where we perform the basic MMU setup, and one for > the runtime. > > Switching between the two was though to be safe, but we've recently > realized that it is not: it is not enough to ensure that the VA->PA > mapping is consistent when switching TTBR0_EL2, but we also have to > ensure that the intermediate translations are the same as well. If the > TLB can return two different values for intermediate translations, > we're screwed (TLB conflicts). > > At that point, the only safe thing to do is to never change TTBR0_EL2, > which means that we need to make the idmap page part of the runtime > page tables. > > The series starts with a bit of brain dumping explaining what we're > trying to do. This might not be useful as a merge candidate, but it > was useful for me to put this somewhere. It goes on revamping the > whole notion of HYP VA range, making it runtime patchable. It then > always merge idmap and runtime page table into one set, leading to > quite a lot of simplification in the init/teardown code. In the > process, 32bit KVM gains the ability to teardown the HYP page-tables > and vectors, which makes kexec a bit closer. > > This has been tested on Seattle, Juno, the FVP model (both v8.0 and > v8.1), Cubietruck and Midway, and is based on the current > kvmarm/queue. > For the series: Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Applied to queue, thanks! -- 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
