RE: [PATCH v2 0/4] Add new headers for Hyper-V Dom0

[Michael Kelley]

From: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> Sent: Monday, November 11, 2024 10:00 AM
> 
> On 11/10/2024 8:12 PM, Michael Kelley wrote:
> > From: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> Sent: Thursday, November 7, 2024 2:32 PM
> >>
> >> To support Hyper-V Dom0 (aka Linux as root partition), many new
> >> definitions are required.
> >
> > Using "dom0" terminology here and in the Subject: line is likely to
> > be confusing to folks who aren't intimately involved in Hyper-V work.
> > Previous Linux kernel commit messages and code for running in the
> > Hyper-V root partition use "root partition" terminology, and I couldn't
> > find "dom0" having been used before. "root partition" would be more
> > consistent, and it also matches the public documentation for Hyper-V.
> > "dom0" is Xen specific terminology, and having it show up in Hyper-V
> > patches would be confusing for the casual reader. I know "dom0" has
> > been used internally at Microsoft as shorthand for "Hyper-V root
> > partition", but it's probably best to completely avoid such shorthand
> > in public Linux kernel patches and code.
> >
> > Just my $.02 ....
> >
> 
> Noted - I will update the terminology in v3 and generally avoid "Dom0",
> except possibly by way of explanation (i.e. to compare it to Xen Dom0).

Yes, I'm good with comparing the Hyper-V root partition to Xen dom0 as
part of an explanation.

Michael

> 
> Thanks
> Nuno
> 
> >>
> >> The plan going forward is to directly import definitions from
> >> Hyper-V code without waiting for them to land in the TLFS document.
> >> This is a quicker and more maintainable way to import definitions,
> >> and is a step toward the eventual goal of exporting headers directly
> >> from Hyper-V for use in Linux.
> >>
> >> This patch series introduces new headers (hvhdk.h, hvgdk.h, etc,
> >> see patch #3) derived directly from Hyper-V code. hyperv-tlfs.h is
> >> replaced with hvhdk.h (which includes the other new headers)
> >> everywhere.
> >>
> >> No functional change is expected.
> >>
> >> Summary:
> >> Patch 1-2: Minor cleanup patches
> >> Patch 3: Add the new headers (hvhdk.h, etc..) in include/hyperv/
> >> Patch 4: Switch to the new headers
> >>
> >> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
> >> ---
> >> Changelog:
> >> v2:
> >> - Rework the series to simply use the new headers everywhere
> >>   instead of fiddling around to keep hyperv-tlfs.h used in some
> >>   places, suggested by Michael Kelley and Easwar Hariharan
> >
> > Thanks! That should be simpler all around.
> >
> > Michael
> >
> >> - Fix compilation errors with some configs by adding missing
> >>   definitions and changing some names, thanks to Simon Horman for
> >>   catching those
> >> - Add additional definitions to the new headers to support them now
> >>   replacing hyperv-tlfs.h everywhere
> >> - Add additional context in the commit messages for patches #3 and #4
> >> - In patch #2, don't remove indirect includes. Only remove includes
> >>   which truly aren't used, suggested by Michael Kelley
> >>
> >> ---
> >> Nuno Das Neves (4):
> >>   hyperv: Move hv_connection_id to hyperv-tlfs.h
> >>   hyperv: Clean up unnecessary #includes
> >>   hyperv: Add new Hyper-V headers in include/hyperv
> >>   hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h
> >>
> >>  arch/arm64/hyperv/hv_core.c        |    3 +-
> >>  arch/arm64/hyperv/mshyperv.c       |    4 +-
> >>  arch/arm64/include/asm/mshyperv.h  |    2 +-
> >>  arch/x86/hyperv/hv_apic.c          |    1 -
> >>  arch/x86/hyperv/hv_init.c          |   21 +-
> >>  arch/x86/hyperv/hv_proc.c          |    3 +-
> >>  arch/x86/hyperv/ivm.c              |    1 -
> >>  arch/x86/hyperv/mmu.c              |    1 -
> >>  arch/x86/hyperv/nested.c           |    2 +-
> >>  arch/x86/include/asm/kvm_host.h    |    3 +-
> >>  arch/x86/include/asm/mshyperv.h    |    3 +-
> >>  arch/x86/include/asm/svm.h         |    2 +-
> >>  arch/x86/kernel/cpu/mshyperv.c     |    2 +-
> >>  arch/x86/kvm/vmx/hyperv_evmcs.h    |    2 +-
> >>  arch/x86/kvm/vmx/vmx_onhyperv.h    |    2 +-
> >>  arch/x86/mm/pat/set_memory.c       |    2 -
> >>  drivers/clocksource/hyperv_timer.c |    2 +-
> >>  drivers/hv/hv_balloon.c            |    4 +-
> >>  drivers/hv/hv_common.c             |    2 +-
> >>  drivers/hv/hv_kvp.c                |    2 +-
> >>  drivers/hv/hv_snapshot.c           |    2 +-
> >>  drivers/hv/hyperv_vmbus.h          |    2 +-
> >>  include/asm-generic/hyperv-tlfs.h  |    9 +
> >>  include/asm-generic/mshyperv.h     |    2 +-
> >>  include/clocksource/hyperv_timer.h |    2 +-
> >>  include/hyperv/hvgdk.h             |  303 +++++++
> >>  include/hyperv/hvgdk_ext.h         |   46 +
> >>  include/hyperv/hvgdk_mini.h        | 1295 ++++++++++++++++++++++++++++
> >>  include/hyperv/hvhdk.h             |  733 ++++++++++++++++
> >>  include/hyperv/hvhdk_mini.h        |  310 +++++++
> >>  include/linux/hyperv.h             |   11 +-
> >>  net/vmw_vsock/hyperv_transport.c   |    2 +-
> >>  32 files changed, 2729 insertions(+), 52 deletions(-)
> >>  create mode 100644 include/hyperv/hvgdk.h
> >>  create mode 100644 include/hyperv/hvgdk_ext.h
> >>  create mode 100644 include/hyperv/hvgdk_mini.h
> >>  create mode 100644 include/hyperv/hvhdk.h
> >>  create mode 100644 include/hyperv/hvhdk_mini.h
> >>
> >> --
> >> 2.34.1