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

From: mhkelley58
Date: Wed Aug 29 2018 - 11:43:20 EST

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

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