Drivers: hv: Export some functions for use by root partition module

hv_get_hypervisor_version(), hv_call_deposit_pages(), and
hv_call_create_vp(), are all needed in-module with CONFIG_MSHV_ROOT=m.

Drivers: hv: Export some functions for use by root partition module

hv_get_hypervisor_version(), hv_call_deposit_pages(), and
hv_call_create_vp(), are all needed in-module with CONFIG_MSHV_ROOT=m.

Signed-off-by: Nuno Das Neves <[email protected]>
Reviewed-by: Stanislav Kinsburskii <[email protected]>
Reviewed-by: Roman Kisel <[email protected]>
Reviewed-by: Easwar Hariharan <[email protected]>
Reviewed-by: Tianyu Lan <[email protected]>
Link: https://lore.kernel.org/r/1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com>

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hyperv: Change hv_root_partition into a function

Introduce hv_curr_partition_type to store the partition type
as an enum.

Right now this is limited to guest or root partition, but there will
be oth

hyperv: Change hv_root_partition into a function

Introduce hv_curr_partition_type to store the partition type
as an enum.

Right now this is limited to guest or root partition, but there will
be other kinds in future and the enum is easily extensible.

Set up hv_curr_partition_type early in Hyper-V initialization with
hv_identify_partition_type(). hv_root_partition() just queries this
value, and shouldn't be called before that.

Making this check into a function sets the stage for adding a config
option to gate the compilation of root partition code. In particular,
hv_root_partition() can be stubbed out always be false if root
partition support isn't desired.

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/1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com>

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hyperv: Move hv_current_partition_id to arch-generic code

Move hv_current_partition_id and hv_get_partition_id() to hv_common.c,
and call hv_get_partition_id() on arm64 in hyperv_init(). These aren'

hyperv: Move hv_current_partition_id to arch-generic code

Move hv_current_partition_id and hv_get_partition_id() to hv_common.c,
and call hv_get_partition_id() on arm64 in hyperv_init(). These aren't
specific to x86_64 and will be needed by common code.

Set hv_current_partition_id to HV_PARTITION_ID_SELF by default.

Rename struct hv_get_partition_id to hv_output_get_partition_id, to
make it distinct from the function hv_get_partition_id(), and match
the original Hyper-V struct name.

Remove the BUG()s. Failing to get the id need not crash the machine.

Signed-off-by: Nuno Das Neves <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/1738955002-20821-2-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1738955002-20821-2-git-send-email-nunodasneves@linux.microsoft.com>

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hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h

Switch to using hvhdk.h everywhere in the kernel. This header
includes all the new Hyper-V headers in include/hyperv, which form a
superset of the

hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h

Switch to using hvhdk.h everywhere in the kernel. This header
includes all the new Hyper-V headers in include/hyperv, which form a
superset of the definitions found in hyperv-tlfs.h.

This makes it easier to add new Hyper-V interfaces without being
restricted to those in the TLFS doc (reflected in hyperv-tlfs.h).

To be more consistent with the original Hyper-V code, the names of
some definitions are changed slightly. Update those where needed.

Update comments in mshyperv.h files to point to include/hyperv for
adding new definitions.

Signed-off-by: Nuno Das Neves <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Reviewed-by: Easwar Hariharan <[email protected]>
Signed-off-by: Roman Kisel <[email protected]>
Reviewed-by: Easwar Hariharan <[email protected]>
Link: https://lore.kernel.org/r/1732577084-2122-5-git-send-email-nunodasneves@linux.microsoft.com
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wei Liu <[email protected]>

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x86/hyperv: Use Hyper-V entropy to seed guest random number generator

A Hyper-V host provides its guest VMs with entropy in a custom ACPI
table named "OEM0". The entropy bits are updated each time

x86/hyperv: Use Hyper-V entropy to seed guest random number generator

A Hyper-V host provides its guest VMs with entropy in a custom ACPI
table named "OEM0". The entropy bits are updated each time Hyper-V
boots the VM, and are suitable for seeding the Linux guest random
number generator (rng). See a brief description of OEM0 in [1].

Generation 2 VMs on Hyper-V use UEFI to boot. Existing EFI code in
Linux seeds the rng with entropy bits from the EFI_RNG_PROTOCOL.
Via this path, the rng is seeded very early during boot with good
entropy. The ACPI OEM0 table provided in such VMs is an additional
source of entropy.

Generation 1 VMs on Hyper-V boot from BIOS. For these VMs, Linux
doesn't currently get any entropy from the Hyper-V host. While this
is not fundamentally broken because Linux can generate its own entropy,
using the Hyper-V host provided entropy would get the rng off to a
better start and would do so earlier in the boot process.

Improve the rng seeding for Generation 1 VMs by having Hyper-V specific
code in Linux take advantage of the OEM0 table to seed the rng. For
Generation 2 VMs, use the OEM0 table to provide additional entropy
beyond the EFI_RNG_PROTOCOL. Because the OEM0 table is custom to
Hyper-V, parse it directly in the Hyper-V code in the Linux kernel
and use add_bootloader_randomness() to add it to the rng. Once the
entropy bits are read from OEM0, zero them out in the table so
they don't appear in /sys/firmware/acpi/tables/OEM0 in the running
VM. The zero'ing is done out of an abundance of caution to avoid
potential security risks to the rng. Also set the OEM0 data length
to zero so a kexec or other subsequent use of the table won't try
to use the zero'ed bits.

[1] https://download.microsoft.com/download/1/c/9/1c9813b8-089c-4fef-b2ad-ad80e79403ba/Whitepaper%20-%20The%20Windows%2010%20random%20number%20generation%20infrastructure.pdf

Signed-off-by: Michael Kelley <[email protected]>
Reviewed-by: Jason A. Donenfeld <[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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hyperv-tlfs: Rename some HV_REGISTER_* defines for consistency

Rename HV_REGISTER_GUEST_OSID to HV_REGISTER_GUEST_OS_ID. This matches
the existing HV_X64_MSR_GUEST_OS_ID.

Rename HV_REGISTER_CRASH_*

hyperv-tlfs: Rename some HV_REGISTER_* defines for consistency

Rename HV_REGISTER_GUEST_OSID to HV_REGISTER_GUEST_OS_ID. This matches
the existing HV_X64_MSR_GUEST_OS_ID.

Rename HV_REGISTER_CRASH_* to HV_REGISTER_GUEST_CRASH_*. Including
GUEST_ is consistent with other #defines such as
HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE. The new names also match the TLFS
document more accurately, i.e. HvRegisterGuestCrash*.

Signed-off-by: Nuno Das Neves <[email protected]>
Link: https://lore.kernel.org/r/1710285687-9160-1-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1710285687-9160-1-git-send-email-nunodasneves@linux.microsoft.com>

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mshyperv: Introduce hv_get_hypervisor_version function

Introduce x86_64 and arm64 functions to get the hypervisor version
information and store it in a structure for simpler parsing.

Use the new fu

mshyperv: Introduce hv_get_hypervisor_version function

Introduce x86_64 and arm64 functions to get the hypervisor version
information and store it in a structure for simpler parsing.

Use the new function to get and parse the version at boot time. While at
it, move the printing code to hv_common_init() so it is not duplicated.

Signed-off-by: Nuno Das Neves <[email protected]>
Acked-by: Wei Liu <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Link: https://lore.kernel.org/r/1709852618-29110-1-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <[email protected]>
Message-ID: <1709852618-29110-1-git-send-email-nunodasneves@linux.microsoft.com>

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arm64/hyperv: Use CPUHP_AP_HYPERV_ONLINE state to fix CPU online sequencing

State CPUHP_AP_HYPERV_ONLINE has been introduced to correctly sequence the
initialization of hyperv_pcpu_input_arg. Use th

arm64/hyperv: Use CPUHP_AP_HYPERV_ONLINE state to fix CPU online sequencing

State CPUHP_AP_HYPERV_ONLINE has been introduced to correctly sequence the
initialization of hyperv_pcpu_input_arg. Use this new state for Hyper-V
initialization so that hyperv_pcpu_input_arg is allocated early enough.

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

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hyperv: simplify and rename generate_guest_id

The generate_guest_id function is more suitable for use after the
following modifications.

1. The return value of the function is modified to u64.
2. R

hyperv: simplify and rename generate_guest_id

The generate_guest_id function is more suitable for use after the
following modifications.

1. The return value of the function is modified to u64.
2. Remove the d_info1 and d_info2 parameters from the function, keep the
u64 type kernel_version parameter.
3. Rename the function to make it clearly a Hyper-V related function,
and modify it to hv_generate_guest_id.

Signed-off-by: Li kunyu <[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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arm64: hyperv: Initialize hypervisor on boot

Add ARM64-specific code to initialize the Hyper-V
hypervisor when booting as a guest VM.

This code is built only when CONFIG_HYPERV is enabled.

Signed-

arm64: hyperv: Initialize hypervisor on boot

Add ARM64-specific code to initialize the Hyper-V
hypervisor when booting as a guest VM.

This code is built only when CONFIG_HYPERV is enabled.

Signed-off-by: Michael Kelley <[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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