[PATCH v4 0/2] ARM64 support for doorbell and intercept SINTs

From: Anirudh Rayabharam

Date: Wed Feb 11 2026 - 12:09:33 EST


From: "Anirudh Rayabharam (Microsoft)" <anirudh@xxxxxxxxxxxxx>

On x86, the HYPERVISOR_CALLBACK_VECTOR is used to receive synthetic
interrupts (SINTs) from the hypervisor for doorbells and intercepts.
There is no such vector reserved for arm64.

On arm64, the hypervisor exposes a synthetic register that can be read
to find the INTID that should be used for SINTs. This INTID is in the
PPI range.

Changes in v4:
- Hypervisor now exposes a synthetic register to read the SINT vector
instead of using an ACPI platform device. So make changes to accomodate that.

Changes in v3:
- Moved the hv_root_partition() check into the reboot notifier
to avoid doing it multiple times.

v2: https://lore.kernel.org/linux-hyperv/20260202182706.648192-1-anirudh@xxxxxxxxxxxxx/
Changes in v2:
Addressed review comments:
- Moved more stuff into mshv_synic.c
- Code simplifications
- Removed unnecessary debug prints

v1: https://lore.kernel.org/linux-hyperv/20260128160437.3342167-1-anirudh@xxxxxxxxxxxxx/

Anirudh Rayabharam (Microsoft) (2):
mshv: refactor synic init and cleanup
mshv: add arm64 support for doorbell & intercept SINTs

drivers/hv/mshv_root.h | 5 +-
drivers/hv/mshv_root_main.c | 59 ++----------
drivers/hv/mshv_synic.c | 181 +++++++++++++++++++++++++++++++++---
include/hyperv/hvgdk_mini.h | 2 +
4 files changed, 181 insertions(+), 66 deletions(-)

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2.34.1