Pull Hyper-V updates from Wei Liu:

 - Fix cross-compilation for hv tools (Aditya Garg)

 - Fix vmemmap_shift exceeding MAX_FOLIO_ORDER in mshv_vtl (Naman Jain)

 - Limit channel interrupt scan to relid high water mark (Michael
   Kelley)

 - Export hv_vmbus_exists() and use it in pci-hyperv (Dexuan Cui)

 - Fix cleanup and shutdown issues for MSHV (Jork Loeser)

 - Introduce more tracing support for MSHV (Stanislav Kinsburskii)

* tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Skip LP/VP creation on kexec
  x86/hyperv: move stimer cleanup to hv_machine_shutdown()
  Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing
  mshv: Add tracepoint for GPA intercept handling
  mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER
  tools: hv: Fix cross-compilation
  Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv
  mshv: Introduce tracing support
  Drivers: hv: vmbus: Limit channel interrupt scan to relid high water mark

After a kexec the logical processors and virtual processors already
exist in the hypervisor because they were created by the previous
kernel. Attempting to add them again causes either a BUG_ON or
corrupted VP state leading to MCEs in the new kernel.

Add hv_lp_exists() to probe whether an LP is already present by
calling HVCALL_GET_LOGICAL_PROCESSOR_RUN_TIME. When it succeeds the
LP exists and we skip the add-LP and create-VP loops entirely.

Also add hv_call_notify_all_processors_started() which informs the
hypervisor that all processors are online. This is required after
adding LPs (fresh boot) and is a no-op on kexec since we skip that
path.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Co-developed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Signed-off-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Move hv_stimer_global_cleanup() from vmbus's hv_kexec_handler() to
hv_machine_shutdown() in the platform code. This ensures stimer cleanup
happens before the vmbus unload, which is required for root partition
kexec to work correctly.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

The Hyper-V ISRs, for normal guests and when running in the hypervisor root
patition, are calling add_interrupt_randomness() as a primary source of
entropy. The call is currently in the ISRs as a common place to handle both
x86/x64 and arm64.

On x86/x64, hypervisor interrupts come through a custom sysvec entry, and
do not go through a generic interrupt handler.

On arm64, hypervisor interrupts come through an emulated GICv3. GICv3 uses
the generic handler handle_percpu_devid_irq(), which does not do
add_interrupt_randomness() -- unlike its counterpart
handle_percpu_irq().

But handle_percpu_devid_irq() is now updated to do the
add_interrupt_randomness(). So add_interrupt_randomness() is now needed
only in Hyper-V's x86/x64 custom sysvec path.

Move add_interrupt_randomness() from the Hyper-V ISRs into the Hyper-V
x86/x64 custom sysvec path, matching the existing STIMER0 sysvec path.

With this change, add_interrupt_randomness() is no longer called from any
device drivers, which is appropriate.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://patch.msgid.link/20260402202400.1707-3-mhklkml@zohomail.com

Signed-off-by: Wei Liu <wei.liu@kernel.org>

MSVC compiler, used to compile the Microsoft Hypervisor, currently
has an assert intrinsic that uses interrupt vector 0x29 to create an
exception. This will cause hypervisor to then crash and collect core. As
such, if this interrupt number is assigned to a device by Linux and the
device generates it, hypervisor will crash. There are two other such
vectors hard coded in the hypervisor, 0x2C and 0x2D for debug purposes.

Fortunately, the three vectors are part of the kernel driver space and
that makes it feasible to reserve them early so they are not assigned
later.

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

Root partitions running on MSHV currently attempt ACPI power-off, which
MSHV intercepts and triggers a Machine Check Exception (MCE), leading
to a kernel panic.

Root partitions panic with a trace similar to:

  [   81.306348] reboot: Power down
  [   81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001
  [   81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9
  [   81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff
  [   81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
  [   81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt
  [   81.314717] Kernel panic - not syncing: Fatal machine check

To avoid this, configure the sleep state in the hypervisor and invoke
the HVCALL_ENTER_SLEEP_STATE hypercall as the final step in the shutdown
sequence. This ensures a clean and safe shutdown of the root partition.

Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com>
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Rename hv_machine_crash_shutdown to more appropriate
hv_guest_crash_shutdown and make it applicable to guests only. This
in preparation for the subsequent hypervisor root crash support
patches.

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

./arch/x86/kernel/cpu/mshyperv.c: asm/msr.h is included more than once.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=26164
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

hv_set_non_nested_msr() has special handling for SINT MSRs
when a paravisor is present. In addition to updating the MSR on the
host, the mirror MSR in the paravisor is updated, including with the
proxy bit. But with Confidential VMBus, the proxy bit must not be
used, so add a special case to skip it.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>