[RFC PATCH v8 0/7] Enable ptp_kvm for arm64

[Jianyong Wu]

kvm ptp targets to provide high precision time sync between guest
and host in virtualization environment. Here, we enable kvm ptp
for arm64.
This patch set base on [1][2][3]

change log:

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.

[1]https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/
commit/?h=kvm/hvc&id=125ea89e4a21e2fc5235410f966a996a1a7148bf
[2]https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/
commit/?h=kvm/hvc&id=464f5a1741e5959c3e4d2be1966ae0093b4dce06
[3]https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/
commit/?h=kvm/hvc&id=6597490e005d0eeca8ed8c1c1d7b4318ee014681
[4]https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/
commit/?h=for-next/smccc-conduit-cleanup&id=6b7fe77c334ae59fed9500140e08f4f896b36871

Jianyong Wu (6):
  psci: let arm_smccc_1_1_invoke available by modules
  ptp: Reorganize ptp_kvm modules to make it arch-independent.
  clocksource: Add clocksource id for arm arch counter
  psci: Add hvc call service for ptp_kvm.
  ptp: arm64: Enable ptp_kvm for arm64
  kvm: arm64: Add capability check extension for ptp_kvm

Mark Rutland (1):
  arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

Thomas Gleixner (1):
  time: Add mechanism to recognize clocksource in time_get_snapshot

 drivers/clocksource/arm_arch_timer.c        | 24 ++++++
 drivers/firmware/psci/psci.c                | 16 ++++
 drivers/ptp/Kconfig                         |  2 +-
 drivers/ptp/Makefile                        |  1 +
 drivers/ptp/ptp_kvm_arm64.c                 | 53 +++++++++++++
 drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} | 77 +++++-------------
 drivers/ptp/ptp_kvm_x86.c                   | 87 +++++++++++++++++++++
 include/asm-generic/ptp_kvm.h               | 12 +++
 include/linux/arm-smccc.h                   | 30 ++++++-
 include/linux/clocksource.h                 |  6 ++
 include/linux/clocksource_ids.h             | 13 +++
 include/linux/timekeeping.h                 | 12 +--
 include/uapi/linux/kvm.h                    |  1 +
 kernel/time/clocksource.c                   |  3 +
 kernel/time/timekeeping.c                   |  1 +
 virt/kvm/arm/arm.c                          |  1 +
 virt/kvm/arm/psci.c                         | 22 ++++++
 17 files changed, 295 insertions(+), 66 deletions(-)
 create mode 100644 drivers/ptp/ptp_kvm_arm64.c
 rename drivers/ptp/{ptp_kvm.c => ptp_kvm_common.c} (63%)
 create mode 100644 drivers/ptp/ptp_kvm_x86.c
 create mode 100644 include/asm-generic/ptp_kvm.h
 create mode 100644 include/linux/clocksource_ids.h

-- 
2.17.1