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

[KY Srinivasan]

> -----Original Message-----
> From: kys@xxxxxxxxxxxxxxxxx <kys@xxxxxxxxxxxxxxxxx>
> Sent: Wednesday, November 21, 2018 6:51 PM
> To: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx;
> jasowang@xxxxxxxxxx; Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>;
> Michael Kelley <mikelley@xxxxxxxxxxxxx>; vkuznets
> <vkuznets@xxxxxxxxxx>
> Cc: KY Srinivasan <kys@xxxxxxxxxxxxx>
> Subject: [PATCH 0/4] Hyper-V: Enable Linux guests on Hyper-V on ARM64
> 
> From: "K. Y. Srinivasan" <kys@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.
> 
> 
> 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                          |   4 +
>  arch/arm64/Makefile                  |   1 +
>  arch/arm64/hyperv/Makefile           |   2 +
>  arch/arm64/hyperv/hv_hvc.S           |  54 ++++
>  arch/arm64/hyperv/hv_init.c          | 441 +++++++++++++++++++++++++++
>  arch/arm64/hyperv/mshyperv.c         | 178 +++++++++++
>  arch/arm64/include/asm/hyperv-tlfs.h | 338 ++++++++++++++++++++
>  arch/arm64/include/asm/mshyperv.h    | 116 +++++++
>  arch/x86/include/asm/mshyperv.h      |   4 +
>  drivers/hv/Kconfig                   |   3 +-
>  drivers/hv/hv.c                      |   2 +
>  include/asm-generic/mshyperv.h       | 240 +++++++++++++++
>  12 files changed, 1382 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
>  create mode 100644 include/asm-generic/mshyperv.h
> 

Greg,

Please drop this. I will be resending shortly.

K. Y
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> 2.19.1