Note: Most of these patches are Arm-specific. People not Cc'd on the whole series can find it in the linux-arm-kernel archive [3]. This series aims to improve the way FPSIMD context is handled by KVM, building on the previous RFC v4 [1]. Patches 1-2 are picked from a separate RFC series [2] since they introduce a helper I wanted to use here. The main changes since RFC v4 are: * Rebased to -rc3. * Patches 1-2 pulled into series from [2], and other patches modified to use it. * Redundant additions by patch 3 that were reverted by other patches are now gone. * New patches 12-14 move the call to __hyp_switch_fpsimd() out of asm completely, moving it to the fixup_guest_exit() path instead. This should significantly cleaner, but does add a bit of overhead to FPSIMD trapping. This is presented as an independent change in case people want to benchmark with/without. Other minor changes as noted. Some testing done on Juno and the Arm fast model (arm64), including combinations of (non-)SVE and (non-)VHE configurations. Cheers ---Dave [1] [RFC PATCH 0/8] KVM: arm64: Optimise FPSIMD context switching http://lists.infradead.org/pipermail/linux-arm-kernel/2018-April/572781.html [2] [RFC PATCH 0/6] Simplify setting thread flags to a particular value https://lkml.org/lkml/2018/4/19/225 [3] linux-arm-kernel archive http://lists.infradead.org/pipermail/linux-arm-kernel/2018-May/thread.html Christoffer Dall (1): KVM: arm/arm64: Introduce kvm_arch_vcpu_run_pid_change Dave Martin (13): thread_info: Add update_thread_flag() helpers arm64: Use update{,_tsk}_thread_flag() KVM: arm64: Convert lazy FPSIMD context switch trap to C arm64: fpsimd: Generalise context saving for non-task contexts KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing arm64/sve: Move read_zcr_features() out of cpufeature.h arm64/sve: Switch sve_pffr() argument from task to thread arm64/sve: Move sve_pffr() to fpsimd.h and make inline KVM: arm64: Save host SVE context as appropriate KVM: arm64: Remove eager host SVE state saving KVM: arm64: Remove redundant *exit_code changes in fpsimd_guest_exit() KVM: arm64: Fold redundant exit code checks out of fixup_guest_exit() KVM: arm64: Invoke FPSIMD context switch trap from C arch/arm/include/asm/kvm_host.h | 9 ++- arch/arm64/Kconfig | 7 +++ arch/arm64/include/asm/cpufeature.h | 29 --------- arch/arm64/include/asm/fpsimd.h | 20 ++++++ arch/arm64/include/asm/kvm_host.h | 22 ++++--- arch/arm64/include/asm/processor.h | 2 + arch/arm64/kernel/fpsimd.c | 120 +++++++++++++++++------------------ arch/arm64/kernel/ptrace.c | 1 + arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/fpsimd.c | 105 +++++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/entry.S | 43 ------------- arch/arm64/kvm/hyp/hyp-entry.S | 19 ------ arch/arm64/kvm/hyp/switch.c | 121 +++++++++++++++++++++++++----------- include/linux/kvm_host.h | 9 +++ include/linux/sched.h | 6 ++ include/linux/thread_info.h | 11 ++++ virt/kvm/Kconfig | 3 + virt/kvm/arm/arm.c | 25 +++++++- virt/kvm/kvm_main.c | 7 ++- 20 files changed, 360 insertions(+), 202 deletions(-) create mode 100644 arch/arm64/kvm/fpsimd.c -- 2.1.4
