Merge tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

- Enhancements to Linux as the root partition for Microsoft

Merge tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

- Enhancements to Linux as the root partition for Microsoft Hypervisor:
- Support a new mode called L1VH, which allows Linux to drive the
hypervisor running the Azure Host directly
- Support for MSHV crash dump collection
- Allow Linux's memory management subsystem to better manage guest
memory regions
- Fix issues that prevented a clean shutdown of the whole system on
bare metal and nested configurations
- ARM64 support for the MSHV driver
- Various other bug fixes and cleanups

- Add support for Confidential VMBus for Linux guest on Hyper-V

- Secure AVIC support for Linux guests on Hyper-V

- Add the mshv_vtl driver to allow Linux to run as the secure kernel in
a higher virtual trust level for Hyper-V

* tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (58 commits)
mshv: Cleanly shutdown root partition with MSHV
mshv: Use reboot notifier to configure sleep state
mshv: Add definitions for MSHV sleep state configuration
mshv: Add support for movable memory regions
mshv: Add refcount and locking to mem regions
mshv: Fix huge page handling in memory region traversal
mshv: Move region management to mshv_regions.c
mshv: Centralize guest memory region destruction
mshv: Refactor and rename memory region handling functions
mshv: adjust interrupt control structure for ARM64
Drivers: hv: use kmalloc_array() instead of kmalloc()
mshv: Add ioctl for self targeted passthrough hvcalls
Drivers: hv: Introduce mshv_vtl driver
Drivers: hv: Export some symbols for mshv_vtl
static_call: allow using STATIC_CALL_TRAMP_STR() from assembly
mshv: Extend create partition ioctl to support cpu features
mshv: Allow mappings that overlap in uaddr
mshv: Fix create memory region overlap check
mshv: add WQ_PERCPU to alloc_workqueue users
Drivers: hv: Use kmalloc_array() instead of kmalloc()
...

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x86/hyperv: Add trampoline asm code to transition from hypervisor

Introduce a small asm stub to transition from the hypervisor to Linux
after devirtualization. Devirtualization means disabling hyper

x86/hyperv: Add trampoline asm code to transition from hypervisor

Introduce a small asm stub to transition from the hypervisor to Linux
after devirtualization. Devirtualization means disabling hypervisor on
the fly, so after it is done, the code is running on physical processor
instead of virtual, and hypervisor is gone. This can be done by a
root vm only.

At a high level, during panic of either the hypervisor or the root,
the NMI handler asks hypervisor to devirtualize. As part of that,
the arguments include an entry point to return back to Linux. This asm
stub implements that entry point.

The stub is entered in protected mode, uses temporary gdt and page table
to enable long mode and get to kernel entry point which then restores full
kernel context to resume execution to kexec.

Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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