On 25 June 2015 at 18:27, Paolo Bonzini <pbonz...@redhat.com> wrote: > On 25/06/2015 19:08, Andreas Färber wrote: >> And is installing a separate address space per CPU for KVM difficult due >> to kernel limitations, or is this just a few lines of QEMU code that Zhu >> or someone would need to write? :) > > It's basically impossible. Even though support for multiple address > spaces is going to be in Linux 4.2, there are going to be just two: SMM > and not SMM. You don't really want to do O(#cpus) stuff in KVM, where > the number of CPUs can be 200 or more.
Can you explain what the issue is here? Shouldn't it just be a matter of kvm_cpu_exec() doing a dispatch to cpu->as rather than calling address_space_rw() ? (Making it do that was one of the things on my todo list for ARM at some point.) I'm happy to assume that RAM is shared by all CPUs I guess. > TCG is okay because the #cpus is not really going to be more than 4-ish. Well, it might be more than that in future... -- PMM
