From: Richard Henderson <richard.henderson@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Cc: Pavel.Dovgaluk@ispras.ru, peter.maydell@linaro.org
Subject: Re: [Qemu-devel] [PATCH v2] tcg: Really fix cpu_io_recompile
Date: Tue, 20 Mar 2018 08:39:06 +0800 [thread overview]
Message-ID: <bc6e6998-cfcb-09ec-600f-f3c55e208186@linaro.org> (raw)
In-Reply-To: <cb280617-9d27-4f04-ae0d-f30130bd5b8f@redhat.com>
On 03/19/2018 11:54 PM, Paolo Bonzini wrote:
> On 19/03/2018 04:15, Richard Henderson wrote:
>> We have confused the number of instructions that have been
>> executed in the TB with the number of instructions needed
>> to repeat the I/O instruction.
>>
>> We have used cpu_restore_state_from_tb, which means that
>> the guest pc is pointing to the I/O instruction. The only
>> time the answer to the later question is not 1 is when
>> MIPS or SH4 need to re-execute the branch for the delay
>> slot as well.
>>
>> We must rely on cpu->cflags_next_tb to generate the next TB,
>> as otherwise we have a race condition with other guest cpus
>> within the TB cache.
>>
>> Fixes: 0790f86861079b1932679d0f011e431aaf4ee9e2
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>
>> My v1 raced with Paolo's pull request, so v2 now fixes Pavel's fix.
>
> Thanks, let me know if you prefer to send a pull request yourself, or if
> I should include it in the next.
I'm at Linaro Connect this week. Please include this in your next.
r~
next prev parent reply other threads:[~2018-03-20 0:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-19 3:15 [Qemu-devel] [PATCH v2] tcg: Really fix cpu_io_recompile Richard Henderson
2018-03-19 6:30 ` Pavel Dovgalyuk
2018-03-19 15:54 ` Paolo Bonzini
2018-03-20 0:39 ` Richard Henderson [this message]
2018-03-20 0:52 ` Philippe Mathieu-Daudé
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