KVM: arm64: Document HVC_VHE_RESTART stub hypercall

For completeness, let's document the HVC_VHE_RESTART stub.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-19-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Marc Zyngier 2021-02-08 09:57:27 +00:00 committed by Will Deacon
parent 1945a067f3
commit 166cc2a4be

View file

@ -58,6 +58,15 @@ these functions (see arch/arm{,64}/include/asm/virt.h):
into place (arm64 only), and jump to the restart address while at HYP/EL2.
This hypercall is not expected to return to its caller.
* ::
x0 = HVC_VHE_RESTART (arm64 only)
Attempt to upgrade the kernel's exception level from EL1 to EL2 by enabling
the VHE mode. This is conditioned by the CPU supporting VHE, the EL2 MMU
being off, and VHE not being disabled by any other means (command line
option, for example).
Any other value of r0/x0 triggers a hypervisor-specific handling,
which is not documented here.