On Tue, 23 Jun 2020 at 20:37, Richard Henderson <richard.hender...@linaro.org> wrote: > > There are a number of paths by which the TBI is still intact > for user-only in the SVE helpers. > > Because we currently always set TBI for user-only, we do not > need to pass down the actual TBI setting from above, and we > can remove the top byte in the inner-most primitives, so that > none are forgotten. Moreover, this keeps the "dirty" pointer > around at the higher levels, where we need it for any MTE checking. > > Since the normal case, especially for user-only, goes through > RAM, this clearing merely adds two insns per page lookup, which > will be completely in the noise.
Can we have an assert() somewhere suitable that TBI is set? That way if we ever do have an SVE-capable linux-user which doesn't set TBI for some reason we'll get a useful reminder that we need to fix something. Otherwise Reviewed-by: Peter Maydell <peter.mayd...@linaro.org> thanks -- PMM
