Re: [UNIKRAFT PATCH 1/2] plat/kvm: Support non-executable pages on x86

[Costin Lupu <costin.lupu@xxxxxxxxx>]

Reviewed-by: Costin Lupu <costin.lupu@xxxxxxxxx>

On 10/26/20 12:47 PM, stefanl.teodorescu@xxxxxxxxx wrote:
> From: Stefan Teodorescu <stefanl.teodorescu@xxxxxxxxx>
> 
> Setting this bit enables page table entries to have the NX bit set, to
> have the ability to map pages as non-executable. Currently, our whole
> memory is mapped as executable.
> 
> Signed-off-by: Stefan Teodorescu <stefanl.teodorescu@xxxxxxxxx>
> ---
>  plat/kvm/x86/entry64.S | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/plat/kvm/x86/entry64.S b/plat/kvm/x86/entry64.S
> index 274ab0b3..169f4c82 100644
> --- a/plat/kvm/x86/entry64.S
> +++ b/plat/kvm/x86/entry64.S
> @@ -88,6 +88,7 @@ ENTRY(_libkvmplat_start32)
>       movl $0xc0000080, %ecx
>       rdmsr
>       orl $X86_EFER_LME, %eax
> +     orl $X86_EFER_NXE, %eax
>       wrmsr
> 
>       /* 3: load pml4 pointer */
> --
> 2.29.0
> 
>