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From: Peter Maydell <peter.maydell@linaro.org>
Date: Mon, 6 Feb 2017 16:43:46 +0000
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Subject: Re: [Qemu-devel] [PATCH v10 22/23] target-arm: ensure all cross
 vCPUs TLB flushes complete
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To: =?UTF-8?B?QWxleCBCZW5uw6ll?= <alex.bennee@linaro.org>
Cc: Richard Henderson <rth@twiddle.net>, MTTCG Devel <mttcg@listserver.greensocs.com>, QEMU Developers <qemu-devel@nongnu.org>, =?UTF-8?B?S09OUkFEIEZyw6lkw6lyaWM=?= <fred.konrad@greensocs.com>, Alvise Rigo <a.rigo@virtualopensystems.com>, "Emilio G. Cota" <cota@braap.org>, Pranith Kumar <bobby.prani@gmail.com>, Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>, Mark Burton <mark.burton@greensocs.com>, Paolo Bonzini <pbonzini@redhat.com>, Jan Kiszka <jan.kiszka@siemens.com>, Fedorov Sergey <serge.fdrv@gmail.com>, Bamvor Zhang Jian <bamvor.zhangjian@linaro.org>, "open list:ARM" <qemu-arm@nongnu.org>

On 6 February 2017 at 15:31, Alex Benn=C3=A9e <alex.bennee@linaro.org> wrot=
e:
> Previously flushes on other vCPUs would only get serviced when they
> exited their TranslationBlocks. While this isn't overly problematic it
> violates the semantics of TLB flush from the point of view of source
> vCPU.
>
> To solve this we call the cputlb *_all_cpus_synced() functions to do
> the flushes which ensures all flushes are completed by the time the
> vCPU next schedules its own work. As the TLB instructions are modelled
> as CP writes the TB ends at this point meaning cpu->exit_request will
> be checked before the next instruction is executed.
>
> Deferring the work until the architectural sync point is a possible
> future optimisation.
>
> Signed-off-by: Alex Benn=C3=A9e <alex.bennee@linaro.org>
> Reviewed-by: Richard Henderson <rth@twiddle.net>
> ---

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM