Re: [PATCH v3 01/15] KVM: arm64: Check if running in VHE from kvm_host_owns_hyp_mappings()

Will Deacon
2021-12-09T10:12:43Z

On Wed, Dec 01, 2021 at 05:03:55PM +0000, Quentin Perret wrote:
> The kvm_host_owns_hyp_mappings() function should return true if and only
> if the host kernel is responsible for creating the hypervisor stage-1
> mappings. That is only possible in standard non-VHE mode, or during boot
> in protected nVHE mode. But either way, non of this makes sense in VHE,
> so make sure to catch this case as well, hence making the function
> return sensible values in any context (VHE or not).
>
> Suggested-by: Marc Zyngier <maz@kernel.org>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
> arch/arm64/kvm/mmu.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 326cdfec74a1..f8f1096a297f 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -239,6 +239,9 @@ void free_hyp_pgds(void)
>
> static bool kvm_host_owns_hyp_mappings(void)
> {
> + if (is_kernel_in_hyp_mode())
> + return false;

This looks identical to:

https://lore.kernel.org/r/20211208152300.2478542-7-qperret@google.com

Will