On Tue, 5 Oct 2021 00:57:49 +1000, Nicholas Piggin wrote:
> The HPTE B field is a 2-bit field with values 0b10 and 0b11 reserved.
> This field is also taken from the HPTE and used when KVM executes
> TLBIEs to set the B field of those instructions.
>
> Disallow the guest setting B to a reserved value with H_ENTER by
> rejecting it. This is the same approach already taken for rejecting
> reserved (unsupported) LLP values. This prevents the guest from being
> able to induce the host to execute TLBIE with reserved values, which
> is not known to be a problem with current processors but in theory it
> could prevent the TLBIE from working correctly in a future processor.
>
> [...]
Applied to powerpc/next.
[1/1] KVM: PPC: Book3S HV: H_ENTER filter out reserved HPTE[B] value
https://git.kernel.org/powerpc/c/322fda0405fecaaa540b0fa90393830aaadaf420
cheers
