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References: <20140731125321.1600.46604.stgit@PASHA-ISP.novsu.ac.ru>
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From: Alex =?utf-8?Q?Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Thu, 31 Jul 2014 17:07:32 +0100
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Subject: Re: [Qemu-devel] [RFC PATCH v3 15/49] softmmu: fixing usage of
	cpu_st/ld* from helpers
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To: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, mark.burton@greensocs.com, qemu-devel@nongnu.org, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, real@ispras.ru, pbonzini@redhat.com, afaerber@suse.de, fred.konrad@greensocs.com


Pavel Dovgalyuk writes:

> MMU helper functions are called from generated code and other helper
> functions. In both cases they try to get function's return address for
> using it while restoring virtual CPU state.
>
> When MMU helper is called from some other helper function
> (like helper_maskmov_xmm) through cpu_st* function, the return address
> will point to that helper. That is why CPU state cannot be restored in
> the case of MMU fault.
>
> This patch introduces several inline helpers to load return address
> which points to the right place.
>
<snip>

OK I find it fairly hard to follow all the glue magic (not your fault
;-) we have in QEMU. However wouldn't it be simpler for the helper
pre-amble code to ensure the subject pc is updated in the CPU
environment?

Can QEMU only rectify the processor state from a TranlationBlock tc address?

-- 
Alex Bennée