[PATCH v6 00/15] KVM: arm64: Optimise FPSIMD context switching

From: Dave Martin
Date: Tue May 08 2018 - 12:45:13 EST


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.
Only minor changes have been made since the previous v5 [1].
The changes are summarised in the individual patches.

Patch 6 is new, and does some simple refactoring to enable new bits to
be added to an existing vcpu_arch flags field.

Patches 1, 2, 6, 7 and 14 are still missing Reviewed-bys/Acked-bys, so
reviewer attention on these patches would be much appreciated.


Some testing done on Juno and the Arm fast model (arm64), including
(on earlier versions of the patches) combinations of (non-)SVE and
(non-)VHE configurations.

Cheers
---Dave

[1] [PATCH v5 00/14] KVM: arm64: Optimise FPSIMD context switching
http://lists.infradead.org/pipermail/linux-arm-kernel/2018-May/575805.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 (14):
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: Repurpose vcpu_arch.debug_flags for general-purpose flags
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_asm.h | 3 +
arch/arm64/include/asm/kvm_host.h | 24 ++++---
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/debug.c | 8 +--
arch/arm64/kvm/fpsimd.c | 110 ++++++++++++++++++++++++++++++++
arch/arm64/kvm/hyp/debug-sr.c | 6 +-
arch/arm64/kvm/hyp/entry.S | 43 -------------
arch/arm64/kvm/hyp/hyp-entry.S | 19 ------
arch/arm64/kvm/hyp/switch.c | 123 +++++++++++++++++++++++++-----------
arch/arm64/kvm/hyp/sysreg-sr.c | 4 +-
arch/arm64/kvm/sys_regs.c | 8 +--
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 +-
25 files changed, 383 insertions(+), 217 deletions(-)
create mode 100644 arch/arm64/kvm/fpsimd.c

--
2.1.4