Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs

Provide a set of IOCTLs for creating and managing child partitions when
running as root partition on Hyper-V. The new driver is en

Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs

Provide a set of IOCTLs for creating and managing child partitions when
running as root partition on Hyper-V. The new driver is enabled via
CONFIG_MSHV_ROOT.

A brief overview of the interface:

MSHV_CREATE_PARTITION is the entry point, returning a file descriptor
representing a child partition. IOCTLs on this fd can be used to map
memory, create VPs, etc.

Creating a VP returns another file descriptor representing that VP which
in turn has another set of corresponding IOCTLs for running the VP,
getting/setting state, etc.

MSHV_ROOT_HVCALL is a generic "passthrough" hypercall IOCTL which can be
used for a number of partition or VP hypercalls. This is for hypercalls
that do not affect any state in the kernel driver, such as getting and
setting VP registers and partition properties, translating addresses,
etc. It is "passthrough" because the binary input and output for the
hypercall is only interpreted by the VMM - the kernel driver does
nothing but insert the VP and partition id where necessary (which are
always in the same place), and execute the hypercall.

Co-developed-by: Anirudh Rayabharam <[email protected]>
Signed-off-by: Anirudh Rayabharam <[email protected]>
Co-developed-by: Jinank Jain <[email protected]>
Signed-off-by: Jinank Jain <[email protected]>
Co-developed-by: Mukesh Rathor <[email protected]>
Signed-off-by: Mukesh Rathor <[email protected]>
Co-developed-by: Muminul Islam <[email protected]>
Signed-off-by: Muminul Islam <[email protected]>
Co-developed-by: Praveen K Paladugu <[email protected]>
Signed-off-by: Praveen K Paladugu <[email protected]>
Co-developed-by: Stanislav Kinsburskii <[email protected]>
Signed-off-by: Stanislav Kinsburskii <[email protected]>
Co-developed-by: Wei Liu <[email protected]>
Signed-off-by: Nuno Das Neves <[email protected]>
Reviewed-by: Roman Kisel <[email protected]>
Link: https://lore.kernel.org/r/1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com>

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hyperv: Add CONFIG_MSHV_ROOT to gate root partition support

CONFIG_MSHV_ROOT allows kernels built to run as a normal Hyper-V guest
to exclude the root partition code, which is expected to grow
signi

hyperv: Add CONFIG_MSHV_ROOT to gate root partition support

CONFIG_MSHV_ROOT allows kernels built to run as a normal Hyper-V guest
to exclude the root partition code, which is expected to grow
significantly over time.

This option is a tristate so future driver code can be built as a
(m)odule, allowing faster development iteration cycles.

If CONFIG_MSHV_ROOT is disabled, don't compile hv_proc.c, and stub
hv_root_partition() to return false unconditionally. This allows the
compiler to optimize away root partition code blocks since they will
be disabled at compile time.

In the case of booting as root partition *without* CONFIG_MSHV_ROOT
enabled, print a critical error (the kernel will likely crash).

Signed-off-by: Nuno Das Neves <[email protected]>
Reviewed-by: Easwar Hariharan <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com>

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x86/hyperv: Use per cpu initial stack for vtl context

Currently, the secondary CPUs in Hyper-V VTL context lack support for
parallel startup. Therefore, relying on the single initial_stack fetched
f

x86/hyperv: Use per cpu initial stack for vtl context

Currently, the secondary CPUs in Hyper-V VTL context lack support for
parallel startup. Therefore, relying on the single initial_stack fetched
from the current task structure suffices for all vCPUs.

However, common initial_stack risks stack corruption when parallel startup
is enabled. In order to facilitate parallel startup, use the initial_stack
from the per CPU idle thread instead of the current task.

Fixes: 3be1bc2fe9d2 ("x86/hyperv: VTL support for Hyper-V")
Signed-off-by: Saurabh Sengar <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <[email protected]>

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Drivers: hv: Kconfig: Add HYPERV_VTL_MODE

Add HYPERV_VTL_MODE Kconfig flag for VTL mode.

Signed-off-by: Saurabh Sengar <[email protected]>
Reviewed-by: Michael Kelley <mikelley@microsoft.

Drivers: hv: Kconfig: Add HYPERV_VTL_MODE

Add HYPERV_VTL_MODE Kconfig flag for VTL mode.

Signed-off-by: Saurabh Sengar <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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hv_netvsc: Remove second mapping of send and recv buffers

With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mappi

hv_netvsc: Remove second mapping of send and recv buffers

With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mapping for shared memory is no longer necessary. Everything needed
for the transition to shared is handled by set_memory_decrypted().

As such, remove the code to create and manage the second
mapping for the pre-allocated send and recv buffers. This mapping
is the last user of hv_map_memory()/hv_unmap_memory(), so delete
these functions as well. Finally, hv_map_memory() is the last
user of vmap_pfn() in Hyper-V guest code, so remove the Kconfig
selection of VMAP_PFN.

Signed-off-by: Michael Kelley <[email protected]>
Reviewed-by: Tianyu Lan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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Driver: VMBus: Add Devicetree support

Update the driver to support Devicetree boot as well along with ACPI.
At present the Devicetree parsing only provides the mmio region info
and is not the exact

Driver: VMBus: Add Devicetree support

Update the driver to support Devicetree boot as well along with ACPI.
At present the Devicetree parsing only provides the mmio region info
and is not the exact copy of ACPI parsing. This is sufficient to cater
all the current Devicetree usecases for VMBus.

Currently Devicetree is supported only for x86 systems.

Signed-off-by: Saurabh Sengar <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

The hyperv utilities use PTP clock interfaces and should depend a
a kconfig symbol such that they will be built as a loadable module or
builtin

hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

The hyperv utilities use PTP clock interfaces and should depend a
a kconfig symbol such that they will be built as a loadable module or
builtin so that linker errors do not happen.

Prevents these build errors:

ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit':
hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister'
ld: drivers/hv/hv_util.o: in function `hv_timesync_init':
hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'

Fixes: 3716a49a81ba ("hv_utils: implement Hyper-V PTP source")
Signed-off-by: Randy Dunlap <[email protected]>
Reported-by: kernel test robot <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Wei Liu <[email protected]>
Cc: Dexuan Cui <[email protected]>
Cc: [email protected]
Cc: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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Drivers: hv: vmbus: Initialize VMbus ring buffer for Isolation VM

VMbus ring buffer are shared with host and it's need to
be accessed via extra address space of Isolation VM with
AMD SNP support. Th

Drivers: hv: vmbus: Initialize VMbus ring buffer for Isolation VM

VMbus ring buffer are shared with host and it's need to
be accessed via extra address space of Isolation VM with
AMD SNP support. This patch is to map the ring buffer
address in extra address space via vmap_pfn(). Hyperv set
memory host visibility hvcall smears data in the ring buffer
and so reset the ring buffer memory to zero after mapping.

Reviewed-by: Michael Kelley <[email protected]>
Signed-off-by: Tianyu Lan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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Drivers: hv: Enable Hyper-V code to be built on ARM64

Update drivers/hv/Kconfig so CONFIG_HYPERV can be selected on
ARM64, causing the Hyper-V specific code to be built. Exclude the
Hyper-V enlighte

Drivers: hv: Enable Hyper-V code to be built on ARM64

Update drivers/hv/Kconfig so CONFIG_HYPERV can be selected on
ARM64, causing the Hyper-V specific code to be built. Exclude the
Hyper-V enlightened clocks/timers code from being built for ARM64.

Signed-off-by: Michael Kelley <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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x86/Hyper-V: Support for free page reporting

Linux has support for free page reporting now (36e66c554b5c) for
virtualized environment. On Hyper-V when virtually backed VMs are
configured, Hyper-V wi

x86/Hyper-V: Support for free page reporting

Linux has support for free page reporting now (36e66c554b5c) for
virtualized environment. On Hyper-V when virtually backed VMs are
configured, Hyper-V will advertise cold memory discard capability,
when supported. This patch adds the support to hook into the free
page reporting infrastructure and leverage the Hyper-V cold memory
discard hint hypercall to report/free these pages back to the host.

Signed-off-by: Sunil Muthuswamy <[email protected]>
Tested-by: Matheus Castello <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com
Signed-off-by: Wei Liu <[email protected]>

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clocksource/drivers/hyperv: Enable TSC page clocksource on 32bit

There is no particular reason to not enable TSC page clocksource on
32-bit. mul_u64_u64_shr() is available and despite the increased

clocksource/drivers/hyperv: Enable TSC page clocksource on 32bit

There is no particular reason to not enable TSC page clocksource on
32-bit. mul_u64_u64_shr() is available and despite the increased
computational complexity (compared to 64bit) TSC page is still a huge win
compared to MSR-based clocksource.

In-kernel reads:
MSR based clocksource: 3361 cycles
TSC page clocksource: 49 cycles

Reads from userspace (utilizing vDSO in case of TSC page):
MSR based clocksource: 5664 cycles
TSC page clocksource: 131 cycles

Enabling TSC page on 32bits allows to get rid of CONFIG_HYPERV_TSCPAGE as
it is now not any different from CONFIG_HYPERV_TIMER.

Signed-off-by: Vitaly Kuznetsov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

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clocksource/drivers: Make Hyper-V clocksource ISA agnostic

Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as

clocksource/drivers: Make Hyper-V clocksource ISA agnostic

Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as the ISA dependent Hyper-V code under arch/x86.

Consolidate this code and data structures into a Hyper-V clocksource driver
to better follow the Linux model. In doing so, separate out the ISA
dependent portions so the new clocksource driver works for x86 and for the
in-process Hyper-V on ARM64 code.

To start, move the existing clockevents code to create the new clocksource
driver. Update the VMbus driver to call initialization and cleanup routines
since the Hyper-V synthetic timers are not independently enumerated in
ACPI.

No behavior is changed and no new functionality is added.

Suggested-by: Marc Zyngier <[email protected]>
Signed-off-by: Michael Kelley <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Vitaly Kuznetsov <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Sunil Muthuswamy <[email protected]>
Cc: KY Srinivasan <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

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x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbol

Add a special Kconfig symbol X86_HV_CALLBACK_VECTOR so that the guests
using the hypervisor interrupt callback counter can select and thus
e

x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbol

Add a special Kconfig symbol X86_HV_CALLBACK_VECTOR so that the guests
using the hypervisor interrupt callback counter can select and thus
enable that counter. Select it when xen or hyperv support is enabled. No
functional changes.

Signed-off-by: Zhao Yakui <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: [email protected]
Cc: Nicolai Stange <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: x86-ml <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

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x86, hyperv: remove PCI dependency

Need to be able to boot without PCI devices present.

Signed-off-by: Sinan Kaya <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

hv: add SPDX license id to Kconfig

Missing license on Kconfig file.

Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: K. Y. Srinivasan <[email protected]>
Signed-off-by: Greg

hv: add SPDX license id to Kconfig

Missing license on Kconfig file.

Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: K. Y. Srinivasan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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x86/hyper-v: Use hypercall for remote TLB flush

Hyper-V host can suggest us to use hypercall for doing remote TLB flush,
this is supposed to work faster than IPIs.

Implementation details: to do HvF

x86/hyper-v: Use hypercall for remote TLB flush

Hyper-V host can suggest us to use hypercall for doing remote TLB flush,
this is supposed to work faster than IPIs.

Implementation details: to do HvFlushVirtualAddress{Space,List} hypercalls
we need to put the input somewhere in memory and we don't really want to
have memory allocation on each call so we pre-allocate per cpu memory areas
on boot.

pv_ops patching is happening very early so we need to separate
hyperv_setup_mmu_ops() and hyper_alloc_mmu().

It is possible and easy to implement local TLB flushing too and there is
even a hint for that. However, I don't see a room for optimization on the
host side as both hypercall and native tlb flush will result in vmexit. The
hint is also not set on modern Hyper-V versions.

Signed-off-by: Vitaly Kuznetsov <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Stephen Hemminger <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Jork Loeser <[email protected]>
Cc: K. Y. Srinivasan <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Simon Xiao <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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x86/hyperv: Implement hv_get_tsc_page()

To use Hyper-V TSC page clocksource from vDSO we need to make tsc_pg
available. Implement hv_get_tsc_page() and add CONFIG_HYPERV_TSCPAGE to
make #ifdef-s sim

x86/hyperv: Implement hv_get_tsc_page()

To use Hyper-V TSC page clocksource from vDSO we need to make tsc_pg
available. Implement hv_get_tsc_page() and add CONFIG_HYPERV_TSCPAGE to
make #ifdef-s simple.

Signed-off-by: Vitaly Kuznetsov <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Dexuan Cui <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: [email protected]
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

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x86: Make Linux guest support optional

Put all config options needed to run Linux as a guest behind a
CONFIG_HYPERVISOR_GUEST menu so that they don't get built-in by default
but be selectable by the

x86: Make Linux guest support optional

Put all config options needed to run Linux as a guest behind a
CONFIG_HYPERVISOR_GUEST menu so that they don't get built-in by default
but be selectable by the user. Also, make all units which depend on
x86_hyper, depend on this new symbol so that compilation doesn't fail
when CONFIG_HYPERVISOR_GUEST is disabled but those units assume its
presence.

Sort options in the new HYPERVISOR_GUEST menu, adapt config text and
drop redundant select.

Signed-off-by: Borislav Petkov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Cc: Dmitry Torokhov <[email protected]>
Cc: K. Y. Srinivasan <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>

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x86, hyperv: HYPERV depends on X86_LOCAL_APIC

In order to compile in the special Hyper-V interrupt vector, we need
infrastructure in arch/x86/apic/apic.c. At least for now, simply
require CONFIG_X8

x86, hyperv: HYPERV depends on X86_LOCAL_APIC

In order to compile in the special Hyper-V interrupt vector, we need
infrastructure in arch/x86/apic/apic.c. At least for now, simply
require CONFIG_X86_LOCAL_APIC in order to enable CONFIG_HYPERV.

Link: http://lkml.kernel.org/r/[email protected]
Cc: K. Y. Srinivasan <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>

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Drivers: hv: Add Hyper-V balloon driver

Add the basic balloon driver. Windows hosts dynamically manage the guest
memory allocation via a combination memory hot add and ballooning. Memory
hot add is

Drivers: hv: Add Hyper-V balloon driver

Add the basic balloon driver. Windows hosts dynamically manage the guest
memory allocation via a combination memory hot add and ballooning. Memory
hot add is used to grow the guest memory upto the maximum memory that can be
allocatted to the guest. Ballooning is used to both shrink as well as expand
up to the max memory. Supporting hot add needs additional support from the
host. We will support hot add when this support is available. For now,
by setting the VM startup memory to the VM max memory, we can use
ballooning alone to dynamically manage memory allocation amongst
competing guests on a given host.

Signed-off-by: K. Y. Srinivasan <[email protected]>
Reviewed-by: Haiyang Zhang <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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hv: Add Kconfig menu entry

Most of the drivers/*/Kconfig files define a menu entry. Define
a menu item for hv too such that it becomes uniform with e.g.
virtio for at least "make xconfig" and "make

hv: Add Kconfig menu entry

Most of the drivers/*/Kconfig files define a menu entry. Define
a menu item for hv too such that it becomes uniform with e.g.
virtio for at least "make xconfig" and "make menuconfig" users.

Signed-off-by: Bart Van Assche <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: K. Y. Srinivasan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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Staging: hv: move hyperv code out of staging directory

After many years wandering the desert, it is finally time for the
Microsoft HyperV code to move out of the staging directory. Or at least
the

Staging: hv: move hyperv code out of staging directory

After many years wandering the desert, it is finally time for the
Microsoft HyperV code to move out of the staging directory. Or at least
the core hyperv bus code, and the utility driver, the rest still have
some review to get through by the various subsystem maintainers.

Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: K. Y. Srinivasan <[email protected]>

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