Re: [Qemu-devel] [PATCH v5 2/3] tcg: Add declarations and templates of extended MMU helpers

[Richard Henderson <rth@twiddle.net>]

On 10/09/2012 05:37 AM, Yeongkyoon Lee wrote:
> Add declarations and templates of extended MMU helpers.
> An extended helper takes an additional argument of the host address accessing
> a guest memory which differs from the address of the call site to the helper
> because helper call sites locate at the end of a generated code block.
...
> +#ifndef CONFIG_QEMU_LDST_OPTIMIZATION


My feedback from the last round of review is that a version of the
helper functions that take the return address should *always* be available.

There are existing issues in the target-*/foo_helper.c files where
if a helper touches memory that we do no necessarily handle any
fault properly.  This is less true of system mode than user mode,
but it's still a problem.

The helper.c files ought to be changed to use these new "ra-enabled"
routines and pass GETPC().  That way a fault from a helper gets
treated *exactly* like it would if it were called from TCG generated code.

Thus, all this conditionalization should vanish.


r~