On Tue, Jun 23, 2020 at 07:05:07PM +0100, Peter Maydell wrote: > On Wed, 17 Jun 2020 at 13:39, Steven Price <steven.price@xxxxxxx> wrote: > > These patches add support to KVM to enable MTE within a guest. It is > > based on Catalin's v4 MTE user space series[1]. > > > > [1] http://lkml.kernel.org/r/20200515171612.1020-1-catalin.marinas%40arm.com > > > > Posting as an RFC as I'd like feedback on the approach taken. > > What's your plan for handling tags across VM migration? > Will the kernel expose the tag ram to userspace so we > can copy it from the source machine to the destination > at the same time as we copy the actual ram contents ? Qemu can map the guest memory with PROT_MTE and access the tags directly with LDG/STG instructions. Steven was actually asking in the cover letter whether we should require that the VMM maps the guest memory with PROT_MTE as a guarantee that it can access the guest tags. There is no architecturally visible tag ram (tag storage), that's a microarchitecture detail. -- Catalin _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
