Re: [PATCH v4 34/34] KVM: arm64: Protect the .hyp sections from the host

From: Will Deacon
Date: Thu Mar 11 2021 - 14:18:15 EST


On Wed, Mar 10, 2021 at 05:57:51PM +0000, Quentin Perret wrote:
> When KVM runs in nVHE protected mode, use the host stage 2 to unmap the
> hypervisor sections by marking them as owned by the hypervisor itself.
> The long-term goal is to ensure the EL2 code can remain robust
> regardless of the host's state, so this starts by making sure the host
> cannot e.g. write to the .hyp sections directly.
>
> Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/kvm_asm.h | 1 +
> arch/arm64/kvm/arm.c | 46 +++++++++++++++++++
> arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 +
> arch/arm64/kvm/hyp/nvhe/hyp-main.c | 9 ++++
> arch/arm64/kvm/hyp/nvhe/mem_protect.c | 33 +++++++++++++
> 5 files changed, 91 insertions(+)

Acked-by: Will Deacon <will@xxxxxxxxxx>

Will