RE: [RFC PATCH v10 0/9] Enable ptp_kvm for arm/arm64

[Jianyong Wu <Jianyong.Wu@arm.com>]

Hi,
As this version change a lot, expect more comments. thanks.

Thanks
Jianyong 
> -----Original Message-----
> From: Jianyong Wu <jianyong.wu@arm.com>
> Sent: Monday, February 10, 2020 4:49 PM
> To: netdev@vger.kernel.org; yangbo.lu@nxp.com; john.stultz@linaro.org;
> tglx@linutronix.de; pbonzini@redhat.com; sean.j.christopherson@intel.com;
> maz@kernel.org; richardcochran@gmail.com; Mark Rutland
> <Mark.Rutland@arm.com>; will@kernel.org; Suzuki Poulose
> <Suzuki.Poulose@arm.com>; Steven Price <Steven.Price@arm.com>
> Cc: linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; Steve Capper
> <Steve.Capper@arm.com>; Kaly Xin <Kaly.Xin@arm.com>; Justin He
> <Justin.He@arm.com>; Jianyong Wu <Jianyong.Wu@arm.com>; nd
> <nd@arm.com>
> Subject: [RFC PATCH v10 0/9] Enable ptp_kvm for arm/arm64
> 
> kvm ptp targets to provide high precision time sync between guest and host
> in virtualization environment. Here, we enable kvm ptp for arm64.
> 
> change log:
> from v10 to v9
>         (1) change code base to v5.5.
> 	(2) enable ptp_kvm both for arm32 and arm64.
>         (3) let user choose which of virtual counter or physical counter should
> return when using crosstimestamp mode of ptp_kvm for arm/arm64.
>         (4) extend input argument for getcrosstimestamp API.
> 
> from v8 to v9:
>         (1) move ptp_kvm.h to driver/ptp/
>         (2) replace license declaration of ptp_kvm.h the same with other header
> files in the same directory.
> 
> from v7 to v8:
>         (1) separate adding clocksource id for arm_arch_counter as a single
> patch.
>         (2) update commit message for patch 4/8.
>         (3) refine patch 7/8 and patch 8/8 to make them more independent.
> 
> from v6 to v7:
>         (1) include the omitted clocksource_id.h in last version.
>         (2) reorder the header file in patch.
>         (3) refine some words in commit message to make it more impersonal.
> 
> from v5 to v6:
>         (1) apply Mark's patch[4] to get SMCCC conduit.
>         (2) add mechanism to recognize current clocksource by add
> clocksouce_id value into struct clocksource instead of method in patch-v5.
>         (3) rename kvm_arch_ptp_get_clock_fn into
> kvm_arch_ptp_get_crosststamp.
> 
> from v4 to v5:
>         (1) remove hvc delay compensasion as it should leave to userspace.
>         (2) check current clocksource in hvc call service.
>         (3) expose current clocksource by adding it to system_time_snapshot.
>         (4) add helper to check if clocksource is arm_arch_counter.
>         (5) rename kvm_ptp.c to ptp_kvm_common.c
> 
> from v3 to v4:
>         (1) fix clocksource of ptp_kvm to arch_sys_counter.
>         (2) move kvm_arch_ptp_get_clock_fn into arm_arch_timer.c
>         (3) subtract cntvoff before return cycles from host.
>         (4) use ktime_get_snapshot instead of getnstimeofday and
> get_current_counterval to return time and counter value.
>         (5) split ktime and counter into two 32-bit block respectively to avoid
> Y2038-safe issue.
>         (6) set time compensation to device time as half of the delay of hvc call.
>         (7) add ARM_ARCH_TIMER as dependency of ptp_kvm for arm64.
> 
> from v2 to v3:
>         (1) fix some issues in commit log.
>         (2) add some receivers in send list.
> 
> from v1 to v2:
>         (1) move arch-specific code from arch/ to driver/ptp/
>         (2) offer mechanism to inform userspace if ptp_kvm service is available.
>         (3) separate ptp_kvm code for arm64 into hypervisor part and guest part.
>         (4) add API to expose monotonic clock and counter value.
>         (5) refine code: remove no necessary part and reconsitution.
> 
> 
> Jianyong Wu (8):
>   psci: export psci conduit get helper.
>   ptp: Reorganize ptp_kvm modules to make it arch-independent.
>   clocksource: Add clocksource id for arm arch counter
>   psci: Add hypercall service for ptp_kvm.
>   ptp: arm/arm64: Enable ptp_kvm for arm/arm64
>   ptp: extend input argument for getcrosstimestamp API
>   arm/arm64: add mechanism to let user choose which counter to return
>   arm/arm64: Add kvm capability check extension for ptp_kvm
> 
> Thomas Gleixner (1):
>   time: Add mechanism to recognize clocksource in time_get_snapshot
> 
>  drivers/clocksource/arm_arch_timer.c        | 33 ++++++++
>  drivers/firmware/psci/psci.c                |  1 +
>  drivers/net/ethernet/intel/e1000e/ptp.c     |  3 +-
>  drivers/ptp/Kconfig                         |  2 +-
>  drivers/ptp/Makefile                        |  5 ++
>  drivers/ptp/ptp_chardev.c                   |  8 +-
>  drivers/ptp/ptp_kvm.h                       | 11 +++
>  drivers/ptp/ptp_kvm_arm.c                   | 53 +++++++++++++
>  drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} | 83 ++++++--------------
>  drivers/ptp/ptp_kvm_x86.c                   | 87 +++++++++++++++++++++
>  include/linux/arm-smccc.h                   | 21 +++++
>  include/linux/clocksource.h                 |  6 ++
>  include/linux/clocksource_ids.h             | 13 +++
>  include/linux/ptp_clock_kernel.h            |  3 +-
>  include/linux/timekeeping.h                 | 12 +--
>  include/uapi/linux/kvm.h                    |  1 +
>  include/uapi/linux/ptp_clock.h              |  4 +-
>  kernel/time/clocksource.c                   |  3 +
>  kernel/time/timekeeping.c                   |  1 +
>  virt/kvm/arm/arm.c                          |  1 +
>  virt/kvm/arm/hypercalls.c                   | 44 ++++++++++-
>  21 files changed, 323 insertions(+), 72 deletions(-)  create mode 100644
> drivers/ptp/ptp_kvm.h  create mode 100644 drivers/ptp/ptp_kvm_arm.c
> rename drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} (60%)  create mode
> 100644 drivers/ptp/ptp_kvm_x86.c  create mode 100644
> include/linux/clocksource_ids.h
> 
> --
> 2.17.1