arm64: hyperv: Detect Hyper-V via RSI host call in CCA Realms

When booting without ACPI, hyperv_detect_via_smccc() detects Hyper-V by
querying the SMCCC vendor hypervisor UID. In an Arm CCA Realm the SMCCC
call is handled by the RMM rather than by the hypervisor, so the
query never reaches Hyper-V and detection fails.

When running in a Realm, forward ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID
to the host with RSI_HOST_CALL instead, which is how Hyper-V hypercalls
are issued from a Realm.

This is done in the Hyper-V code rather than in the generic
arm_smccc_hypervisor_has_uuid() because the other users expect different
behavior.

hyperv_init() is an early_initcall and runs before the secondary CPUs
are brought up, so a single __initdata host call structure is used
without locking.

ACPI-based detection and non-Realm guests are unaffected.

Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

0 files changed, 0 insertions, 0 deletions