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From: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <7ff01881-3130-ef72-217d-511b4de0cd3c@linaro.org>
Date: Mon, 26 Nov 2018 11:30:25 -0800
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Subject: Re: [Qemu-devel] [RFC 23/48] translator: add plugin_insn argument
 to translate_insn
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To: "Emilio G. Cota" <cota@braap.org>
Cc: =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>, Stefan Hajnoczi <stefanha@gmail.com>, Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org, Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>, =?UTF-8?Q?Llu=c3=ads_Vilanova?= <vilanova@ac.upc.edu>

On 11/26/18 11:07 AM, Emilio G. Cota wrote:
> The main reason why I added the qemu_plugin_insn_append calls
> was to avoid reading the instructions twice from guest memory,
> because I was worried that doing so might somehow alter the
> guest's execution, e.g. what if we read a cross-page instruction,
> and both pages mapped to the same TLB entry? We'd end up having
> more TLB misses because instrumentation was enabled.

A better solution for this, I think is to change direct calls from

  cpu_ldl_code(env, pc);
to
  translator_ldl_code(dc_base, env, pc);

instead of passing around a new argument separate from DisasContextBase?


r~