Re: [Qemu-devel] [PATCH] translate-all.c: Remove writable protection feature for tb_alloc_page()

[Peter Maydell]

On 14 January 2016 at 06:03,  <address@hidden> wrote:
> From: Chen Gang <address@hidden>
>
> Guest may allocate a readable, writable, and executable page, then write
> data on the page, and execute data as code on the page too, then write
> anther data still within the page.
>
> So remove this feature from linux-user: it not only consumes a little
> performance, but also causes issue with the old Linux kernel under some
> of architectures (they will directly generate segment fault for it).

If we don't mark the page as non-writeable when we generate a TB
from it, how do we detect when guest code later writes to that
page (which means we need to invalidate the TB) ?

thanks
-- PMM