From: Richard Henderson <richard.henderson@linaro.org>
To: Andrew Baumann <Andrew.Baumann@microsoft.com>, qemu-devel@nongnu.org
Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] notdirty_mem_write: implement 8-byte accesses
Date: Fri, 13 Oct 2017 13:04:22 -0700 [thread overview]
Message-ID: <669d753c-fa83-8f0a-c366-37f468e9e502@linaro.org> (raw)
In-Reply-To: <20171013181913.7556-1-Andrew.Baumann@microsoft.com>
On 10/13/2017 11:19 AM, Andrew Baumann wrote:
> Aligned 8-byte memory writes by a 64-bit target on a 64-bit host should
> always turn into atomic 8-byte writes on the host, however if we missed
> in the softmmu, and the TLB line was marked as not dirty, then we
> would end up tearing the 8-byte write into two 4-byte writes in
> access_with_adjusted_size().
>
> Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
> ---
> This manifested as a race in lock-free synchronisation with an aarch64
> Windows guest on an x86-64 host (with multithreaded TCG).
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
prev parent reply other threads:[~2017-10-13 20:04 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-13 18:19 [Qemu-devel] [PATCH] notdirty_mem_write: implement 8-byte accesses Andrew Baumann
2017-10-13 18:27 ` Andrew Baumann
2017-10-13 20:04 ` Richard Henderson
2017-10-13 20:04 ` Richard Henderson [this message]
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