Across arm64 we use cpus_have_const_cap() to check for a capability without a runtime check. Prior to capabilities being finalized cpus_have_const_cap() falls back to a runtime check of the cpu_hwcaps array. In some cases we know that code is never invoked prior to the capabilities being finalized, and the fallback code is redundant (and unsound if ever executed in hyp context). So that we can avoid the redundant code and detect when the caps are unexpectedly checked too early, this series adds a new cpus_have_final_cap() helper, and migrates the KVM hyp code over to it. I'm hoping to use this as part of the entry.S -> entry-common.c conversion, and there are other places in arm64 that could potentially use this today. Since v1 [1] * Use system_capabilities_finalized() per Suzuki's comments * Remove extraneous whitespace * Add R-b tags from Marc and Suzuki [1] https://lore.kernel.org/linux-arm-kernel/20200210122708.38826-1-mark.rutland@xxxxxxx/ Thanks, Mark. Mark Rutland (2): arm64: cpufeature: add cpus_have_final_cap() arm64: kvm: hyp: use cpus_have_final_cap() arch/arm64/include/asm/cpufeature.h | 58 ++++++++++++++++++++++++++++++------- arch/arm64/kvm/hyp/switch.c | 14 ++++----- arch/arm64/kvm/hyp/sysreg-sr.c | 8 ++--- arch/arm64/kvm/hyp/tlb.c | 8 ++--- 4 files changed, 62 insertions(+), 26 deletions(-) -- 2.11.0 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
