Commit 166cc2a4 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
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KVM: arm64: Document HVC_VHE_RESTART stub hypercall 



For completeness, let's document the HVC_VHE_RESTART stub.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarDavid Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-19-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 1945a067

Documentation/virt/kvm/arm/hyp-abi.rst

+9 −0
Original line number Diff line number Diff line
@@ -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.