[PATCH v2 0/4] Enable Linux guests on Hyper-V on ARM64

[mhkelley58]

From: Michael Kelley <mikelley@xxxxxxxxxxxxx>

This series enables Linux guests running on Hyper-V on ARM64
hardware. New ARM64-specific code in arch/arm64/hyperv initializes
Hyper-V, including its synthetic clocks and hypercall mechanism.
Existing architecture independent drivers for Hyper-V's VMbus and
synthetic devices just work when built for ARM64. Hyper-V code is
built and included in the image and modules only if CONFIG_HYPERV
is enabled.

The four patches are organized as follows:
1) Add include files that define the Hyper-V interface as
   described in the Hyper-V Top Level Functional Spec (TLFS), plus
   additional definitions specific to Linux running on Hyper-V.

2) Add core Hyper-V support on ARM64, including hypercalls,
   synthetic clock initialization, and interrupt handlers.

3) Update the existing VMbus driver to generalize interrupt
   management across x86/x64 and ARM64.

4) Make CONFIG_HYPERV selectable on ARM64 in addition to x86/x64.

Some areas of Linux guests on Hyper-V on ARM64 are a work-
in-progress, primarily due to work still being done in Hyper-V:

* Hyper-V on ARM64 currently runs with a 4 Kbyte page size, and only
  supports guests with a 4 Kbyte page size. Because Hyper-V uses
  shared pages to communicate between the guest and the hypervisor,
  there are open design decisions on the page size to use when
  the guest is using 16K/64K pages.  Once those issues are
  resolved and Hyper-V fully supports 16K/64K guest pages, changes
  may be needed in the Linux drivers for Hyper-V synthetic devices.

* Hyper-V on ARM64 does not currently support mapping PCI devices
  into the guest address space. The Hyper-V PCI driver at
  drivers/pci/host/pci-hyperv.c has x86/x64-specific code and is
  not being built for ARM64.

In a few cases, terminology from the x86/x64 world has been carried
over into the ARM64 code ("MSR", "TSC").  Hyper-V still uses the
x86/x64 terminology and has not replaced it with something more
generic, so the code uses the Hyper-V terminology.  This will be
fixed when Hyper-V updates the usage in the TLFS.

Changes in v2:
* Remove patch to implement slow_virt_to_phys() on ARM64.
  Use of slow_virt_to_phys() in arch independent Hyper-V
  drivers has been eliminated by commit 6ba34171bcbd
  ("Drivers: hv: vmbus: Remove use of slow_virt_to_phys()")
* Minor tweaks to rebase to latest linux-next code

Michael Kelley (4):
  arm64: hyperv: Add core Hyper-V include files
  arm64: hyperv: Add support for Hyper-V as a hypervisor
  Drivers: hv: vmbus: Add hooks for per-CPU IRQ
  Drivers: hv: Enable CONFIG_HYPERV on ARM64

 MAINTAINERS                          |   3 +
 arch/arm64/Makefile                  |   1 +
 arch/arm64/hyperv/Makefile           |   2 +
 arch/arm64/hyperv/hv_hvc.S           |  54 +++++
 arch/arm64/hyperv/hv_init.c          | 437 +++++++++++++++++++++++++++++++++++
 arch/arm64/hyperv/mshyperv.c         | 178 ++++++++++++++
 arch/arm64/include/asm/hyperv-tlfs.h | 338 +++++++++++++++++++++++++++
 arch/arm64/include/asm/mshyperv.h    | 295 +++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h      |   4 +
 drivers/hv/Kconfig                   |   3 +-
 drivers/hv/hv.c                      |   2 +
 11 files changed, 1316 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/hyperv/Makefile
 create mode 100644 arch/arm64/hyperv/hv_hvc.S
 create mode 100644 arch/arm64/hyperv/hv_init.c
 create mode 100644 arch/arm64/hyperv/mshyperv.c
 create mode 100644 arch/arm64/include/asm/hyperv-tlfs.h
 create mode 100644 arch/arm64/include/asm/mshyperv.h

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1.8.3.1