[PATCH 0/6] x86/kvm/hyperv: stable clocksorce for L2 guests when running nested KVM on Hyper-V

[Vitaly Kuznetsov <vkuznets@redhat.com>]

Changes since RFC:
- Handle disabled TSC page case [Radim Krčmář]
- Function/parameter renames [Radim Krčmář]
- Protect against simultaneous CPU shutdown (future-proof) [Radim Krčmář]
- BUG() in !CONFIG_HYPERV_TSCPAGE case [Stephen Hemminger, Paolo Bonzini]
- Fix build issues (hopefully) [kbuild test robot]
- Fix typos [Andrew Jones]
- Switch to delayed work to workaround a host issue (reported to Microsoft)
Changes are described in the individual patches too.

Original description:

Currently, KVM passes PVCLOCK_TSC_STABLE_BIT to its guests when running in
so called 'masterclock' mode and this is only possible when the clocksource
on the host is TSC. When running nested on Hyper-V we're using a different
clocksource in L1 (Hyper-V TSC Page) which can actually be used for
masterclock. This series brings the required support.

Making KVM work with TSC page clocksource is relatively easy, it is done in
PATCH 5 of the series. All the rest is required to support L1 migration
when TSC frequency changes, we use a special feature from Hyper-V to do
the job.

Vitaly Kuznetsov (6):
  x86/hyper-v: check for required priviliges in hyperv_init()
  x86/hyper-v: add a function to read both TSC and TSC page value
    simulateneously
  x86/hyper-v: reenlightenment notifications support
  x86/hyper-v: redirect reenlightment notifications on CPU offlining
  x86/kvm: pass stable clocksource to guests when running nested on
    Hyper-V
  x86/kvm: support Hyper-V reenlightenment

 arch/x86/entry/entry_64.S          |   4 ++
 arch/x86/hyperv/hv_init.c          | 113 +++++++++++++++++++++++++++++-
 arch/x86/include/asm/entry_arch.h  |   4 ++
 arch/x86/include/asm/hw_irq.h      |   1 +
 arch/x86/include/asm/irq_vectors.h |   7 +-
 arch/x86/include/asm/mshyperv.h    |  31 +++++++--
 arch/x86/include/uapi/asm/hyperv.h |  27 ++++++++
 arch/x86/kernel/idt.c              |   3 +
 arch/x86/kvm/x86.c                 | 138 ++++++++++++++++++++++++++++++-------
 9 files changed, 296 insertions(+), 32 deletions(-)

-- 
2.14.3