The current way we deal with the GIC world switch on arm64 is a bit convoluted. As we have two possible backends, we rely on a couple of indirections set at boot time. These indirection never change, so it would make more sense to directly patch in a branch to the right function. To do this, we introduce a new CPU feature that detect the presence of a GICv3 CPU interface. When detected, we patch branches to the GICv3 save/restore functions that otherwise point to the GICv2 backend. Tested on both GICv2 (Juno, Seattle) and GICv3 (FVP Base model). These patches have been on the various lists for quite a while as part of a series dealing with instruction patching. Now that the prerequisite are queued for 4.2, it would make sense for these to be merged alongside. Catalin, would you mind taking them through the arm64 tree? Marc Zyngier (2): arm64: alternative: Introduce feature for GICv3 CPU interface arm64: KVM: Switch vgic save/restore to alternative_insn arch/arm/include/asm/kvm_host.h | 5 ----- arch/arm64/include/asm/cpufeature.h | 8 +++++++- arch/arm64/include/asm/kvm_asm.h | 5 ----- arch/arm64/include/asm/kvm_host.h | 23 ----------------------- arch/arm64/kernel/asm-offsets.c | 1 - arch/arm64/kernel/cpufeature.c | 16 ++++++++++++++++ arch/arm64/kvm/hyp.S | 18 ++++-------------- virt/kvm/arm/vgic.c | 3 --- 8 files changed, 27 insertions(+), 52 deletions(-) -- 2.1.4 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
