[PATCH] KVM: arm64: Fix reporting of endianess when the access originates at EL0

[Marc Zyngier]

On Tue, 12 Oct 2021 13:00:40 +0100,
Andrew Jones <drjones at redhat.com> wrote:
> 
> On Tue, Oct 12, 2021 at 12:23:12PM +0100, Marc Zyngier wrote:
> > We currently check SCTLR_EL1.EE when computing the address of
> > a faulting guest access. However, the fault could have occured at
> > EL0, in which case the right bit to check would be SCTLR_EL1.E0E.
> > 
> > This is pretty unlikely to cause any issue in practice: You'd have
> > to have a guest with a LE EL1 and a BE EL0 (or the other way around),
> > and have mapped a device into the EL0 page tables.
> 
> I wonder if that's something a usermode network driver might want?

I don't know what it wants, but I don't want it the first place! Think
of what a kernel would need to do to run its userspace in a different
endianness... Userspace device access is just an additional headache.

Whoever does this needs urgent medical attention!

> Reviewed-by: Andrew Jones <drjones at redhat.com>

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.