Re: [PATCH] xen/arm: do not setup the runstate info page if kpti is enabled

[boris . ostrovsky]

On 9/24/20 7:49 PM, Stefano Stabellini wrote:

> From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
>
> The VCPUOP_register_runstate_memory_area hypercall takes a virtual
> address of a buffer as a parameter. The semantics of the hypercall are
> such that the virtual address should always be valid.
>
> When KPTI is enabled and we are running userspace code, the virtual
> address is not valid, thus, Linux is violating the semantics of
> VCPUOP_register_runstate_memory_area.
>
> Do not call VCPUOP_register_runstate_memory_area when KPTI is enabled.
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
> CC: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>
> CC: boris.ostrovsky@xxxxxxxxxx
> CC: jgross@xxxxxxxx


Applied to for-linus-5.10



-boris