From: Richard Henderson <richard.henderson@linaro.org>
To: Florian Weimer <fweimer@redhat.com>, qemu-devel@nongnu.org
Subject: Re: Emulating CPUs with larger atomic accesses
Date: Sat, 21 May 2022 18:07:33 -0700 [thread overview]
Message-ID: <37f4c866-4344-37ba-b64b-fd338dc96887@linaro.org> (raw)
In-Reply-To: <87k0apeor5.fsf@oldenburg.str.redhat.com>
On 5/13/22 03:00, Florian Weimer wrote:
> What's QEMU's approach to emulating CPU instructions that atomatically
> operate on values larger than what is supported by the host CPU?
>
> I assume that for full system emulation, this is not a problem, but
> qemu-user will not achieve atomic behavior on shared memory mappings.
> How much of a problem is this in practice?
Well, it doesn't work, no. In practice, x86_64 supports 128-bit atomic operations, and
guest requires more than that. No one really cares anymore about 32-bit hosts with
smaller atomic operations.
r~
next prev parent reply other threads:[~2022-05-22 1:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-13 10:00 Emulating CPUs with larger atomic accesses Florian Weimer
2022-05-22 1:07 ` Richard Henderson [this message]
2022-05-24 9:27 ` Florian Weimer
2022-05-24 11:48 ` Richard Henderson
2022-05-24 11:51 ` Florian Weimer
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