This series add support for paravirtualized time for arm64 guests and KVM hosts following the specification in Arm's document DEN 0057A: https://developer.arm.com/docs/den0057/a It implements support for stolen time, allowing the guest to identify time when it is forcibly not executing. It doesn't implement support for Live Physical Time (LPT) as there are some concerns about the overheads and approach in the above specification, and I expect an updated version of the specification to be released soon with just the stolen time parts. NOTE: Patches 8 and 9 will conflict with Mark Rutland's series[1] cleaning up the SMCCC conduit. I do feel that the addition of an _invoke() call makes a number of call sites cleaner and it should be possible to integrate both this and Mark's other cleanups. [1] https://lore.kernel.org/linux-arm-kernel/20190809132245.43505-1-mark.rutland@xxxxxxx/ Also available as a git tree: git://linux-arm.org/linux-sp.git stolen_time/v3 Changes from v2: https://lore.kernel.org/lkml/20190819140436.12207-1-steven.price@xxxxxxx/ * Switched from using gfn_to_hva_cache to a new macro kvm_put_guest() that can provide the single-copy atomicity required (on arm64). This macro is added in patch 4. * Tidied up the locking for kvm_update_stolen_time(). pagefault_disable() was unnecessary and the caller didn't need to take kvm->srcu as the function does it itself. * Removed struct kvm_arch_pvtime from the arm implementation, replaced instead with inline static functions which are empty for arm. * Fixed a few checkpatch --strict warnings. Changes from v1: https://lore.kernel.org/lkml/20190802145017.42543-1-steven.price@xxxxxxx/ * Host kernel no longer allocates the stolen time structure, instead it is allocated by user space. This means the save/restore functionality can be removed. * Refactored the code so arm has stub implementations and to avoid initcall * Rebased to pick up Documentation/{virt->virtual} change * Bunch of typo fixes Christoffer Dall (1): KVM: arm/arm64: Factor out hypercall handling from PSCI code Steven Price (9): KVM: arm64: Document PV-time interface KVM: arm64: Implement PV_FEATURES call KVM: Implement kvm_put_guest() KVM: arm64: Support stolen time reporting via shared structure KVM: Allow kvm_device_ops to be const KVM: arm64: Provide a PV_TIME device to user space arm/arm64: Provide a wrapper for SMCCC 1.1 calls arm/arm64: Make use of the SMCCC 1.1 wrapper arm64: Retrieve stolen time as paravirtualized guest Documentation/virt/kvm/arm/pvtime.txt | 100 ++++++++++++++ arch/arm/include/asm/kvm_host.h | 30 +++++ arch/arm/kvm/Makefile | 2 +- arch/arm/kvm/handle_exit.c | 2 +- arch/arm/mm/proc-v7-bugs.c | 13 +- arch/arm64/include/asm/kvm_host.h | 28 +++- arch/arm64/include/asm/paravirt.h | 9 +- arch/arm64/include/asm/pvclock-abi.h | 17 +++ arch/arm64/include/uapi/asm/kvm.h | 8 ++ arch/arm64/kernel/cpu_errata.c | 80 ++++------- arch/arm64/kernel/paravirt.c | 148 +++++++++++++++++++++ arch/arm64/kernel/time.c | 3 + arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/Makefile | 2 + arch/arm64/kvm/handle_exit.c | 4 +- include/kvm/arm_hypercalls.h | 43 ++++++ include/kvm/arm_psci.h | 2 +- include/linux/arm-smccc.h | 58 ++++++++ include/linux/cpuhotplug.h | 1 + include/linux/kvm_host.h | 28 +++- include/linux/kvm_types.h | 2 + include/uapi/linux/kvm.h | 2 + virt/kvm/arm/arm.c | 11 ++ virt/kvm/arm/hypercalls.c | 68 ++++++++++ virt/kvm/arm/psci.c | 84 +----------- virt/kvm/arm/pvtime.c | 182 ++++++++++++++++++++++++++ virt/kvm/kvm_main.c | 6 +- 27 files changed, 780 insertions(+), 154 deletions(-) create mode 100644 Documentation/virt/kvm/arm/pvtime.txt create mode 100644 arch/arm64/include/asm/pvclock-abi.h create mode 100644 include/kvm/arm_hypercalls.h create mode 100644 virt/kvm/arm/hypercalls.c create mode 100644 virt/kvm/arm/pvtime.c -- 2.20.1
