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From: Richard Henderson <rth@twiddle.net>
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Date: Thu, 1 Oct 2015 06:42:42 +1000
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Subject: Re: [Qemu-devel] [RFC v5 3/6] softmmu: Add helpers for a new
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To: alvise rigo <a.rigo@virtualopensystems.com>
Cc: mttcg@greensocs.com, Claudio Fontana <claudio.fontana@huawei.com>, QEMU Developers <qemu-devel@nongnu.org>, Paolo Bonzini <pbonzini@redhat.com>, Jani Kokkonen <jani.kokkonen@huawei.com>, VirtualOpenSystems Technical Team <tech@virtualopensystems.com>, =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>

On 09/30/2015 07:46 PM, alvise rigo wrote:
> On Wed, Sep 30, 2015 at 5:58 AM, Richard Henderson <rth@twiddle.net> wrote:
>> Why would you need to indicate that another cpu has started an exclusive
>> operation on this page?  That seems definitely wrong.
>
> The cpu_physical_memory_clear_excl_dirty() sets the flag to generate
> the TLB entry with the EXCL flag.

Yes, but surely the clearing of dirty on current_cpu is enough to cause the 
other cpus to see that they need to set TLB_EXCL when reloading their tlb entries.

Why do you need to manipulate the *other* cpu's dirty bit?

>> I wonder what can be done to clean all of this up, short of actually
>> transitioning to c++ templates...
>>
>
> Is there already an example in QEMU I can look at?

No.


r~