ARMv8.2 introduced support for VPIPT i-caches, the V standing for VMID-tagged. Although this looks like a reasonable idea, no implementation has ever made it into the wild. Linux has supported this for almost 6 years (amusingly, just as the architecture was dropping support for AVIVT i-caches), but we have no way to even test it, and it is likely that this code is just bit-rotting. This isn't great. Since this only impacts KVM, let's drop the support from the hypervisor. The kernel itself can still work as a guest on such a system, assuming that there is HW and a hypervisor that supports this architecture variation. On the other hand, if you are aware of such an implementation and can actively test KVM on this setup, please shout! M. Marc Zyngier (2): KVM: arm64: Disable KVM on systems with a VPIPT i-cache KVM: arm64: Remove VPIPT I-cache handling arch/arm64/include/asm/kvm_mmu.h | 3 +-- arch/arm64/kvm/arm.c | 5 +++++ arch/arm64/kvm/hyp/nvhe/tlb.c | 35 -------------------------------- arch/arm64/kvm/hyp/vhe/tlb.c | 13 ------------ 4 files changed, 6 insertions(+), 50 deletions(-) -- 2.34.1
