From: Sergey Fedorov <serge.fdrv@gmail.com>
To: Richard Henderson <rth@twiddle.net>,
Pranith Kumar <bobby.prani@gmail.com>
Cc: "open list:All patches CC here" <qemu-devel@nongnu.org>,
"Alex Bennée" <alex.bennee@linaro.org>
Subject: Re: [Qemu-devel] [RFC v2 PATCH 01/13] Introduce TCGOpcode for memory barrier
Date: Thu, 2 Jun 2016 19:18:34 +0300 [thread overview]
Message-ID: <57505C5A.7070609@gmail.com> (raw)
In-Reply-To: <016450d7-f6b9-ef14-9ef0-96d78eb1ac5c@twiddle.net>
On 02/06/16 00:35, Richard Henderson wrote:
> On 06/01/2016 11:43 AM, Pranith Kumar wrote:
>> All we want to do here is map a barrier instruction from guest to a
>> barrier instruction on hist. This mapping is 1:1 if the host has
>> barrier instructions with matching semantics. Otherwise we generate a
>> multi-op instruction sequence. Some examples are: load acquire(ldar)
>> on ARM64 guest will map to dmb+load on ARMv7 target, store
>> fence(sfence) on x86 guest will map to dmb on ARMv7 target.
>
> Perhaps we should model this like the Sparc membar instruction, with
> individual bits for all combinations of Load x Store. One can then
> describe exactly what the target semantics are for each barrier.
Seconded. Given that we don't support Alpha host we can ignore its
unique "Dependent loads reordered" feature. I suppose we're not going to
add Alpha host support :)
Kind regards,
Sergey
next prev parent reply other threads:[~2016-06-02 16:18 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 18:39 [Qemu-devel] [RFC v2 PATCH 00/13] tcg: Add fence gen support Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 01/13] Introduce TCGOpcode for memory barrier Pranith Kumar
2016-05-31 20:24 ` Richard Henderson
2016-06-01 18:43 ` Pranith Kumar
2016-06-01 21:35 ` Richard Henderson
2016-06-02 16:18 ` Sergey Fedorov [this message]
2016-06-02 16:30 ` Sergey Fedorov
2016-06-02 18:42 ` Pranith Kumar
2016-06-02 20:36 ` Richard Henderson
2016-06-02 20:36 ` Richard Henderson
2016-06-02 20:38 ` Sergey Fedorov
2016-06-02 21:18 ` Richard Henderson
2016-06-02 21:37 ` Sergey Fedorov
2016-06-03 1:08 ` Richard Henderson
2016-06-03 15:16 ` Sergey Fedorov
2016-06-03 15:45 ` Richard Henderson
2016-06-03 16:06 ` Sergey Fedorov
2016-06-03 18:30 ` Pranith Kumar
2016-06-03 19:49 ` Sergey Fedorov
2016-06-03 20:43 ` Peter Maydell
2016-06-03 21:33 ` Sergey Fedorov
2016-06-06 16:19 ` Alex Bennée
2016-06-03 18:27 ` Pranith Kumar
2016-06-03 19:52 ` Sergey Fedorov
2016-06-06 15:44 ` Sergey Fedorov
2016-06-06 15:47 ` Pranith Kumar
2016-06-06 15:49 ` Sergey Fedorov
2016-06-06 15:58 ` Pranith Kumar
2016-06-06 16:14 ` Sergey Fedorov
2016-06-06 17:11 ` Pranith Kumar
2016-06-06 19:23 ` Richard Henderson
2016-06-06 19:28 ` Pranith Kumar
2016-06-06 20:30 ` Sergey Fedorov
2016-06-06 21:00 ` Peter Maydell
2016-06-06 21:49 ` Sergey Fedorov
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 02/13] tcg/i386: Add support for fence Pranith Kumar
2016-05-31 20:27 ` Richard Henderson
2016-06-01 18:49 ` Pranith Kumar
2016-06-01 21:17 ` Richard Henderson
2016-06-01 21:44 ` Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 03/13] tcg/aarch64: " Pranith Kumar
2016-05-31 18:59 ` Claudio Fontana
2016-05-31 20:34 ` Richard Henderson
2016-06-16 22:03 ` Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 04/13] tcg/arm: " Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 05/13] tcg/ia64: " Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 06/13] tcg/mips: " Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 07/13] tcg/ppc: " Pranith Kumar
2016-05-31 20:41 ` Richard Henderson
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 08/13] tcg/s390: " Pranith Kumar
2016-06-02 19:31 ` Sergey Fedorov
2016-06-02 20:38 ` Richard Henderson
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 09/13] tcg/sparc: " Pranith Kumar
2016-05-31 20:45 ` Richard Henderson
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 10/13] tcg/tci: " Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 11/13] target-arm: Generate fences in ARMv7 frontend Pranith Kumar
2016-06-02 19:37 ` Sergey Fedorov
2016-06-04 14:50 ` Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 12/13] target-alpha: Generate fence op Pranith Kumar
2016-05-31 18:39 ` [Qemu-devel] [RFC v2 PATCH 13/13] tcg: Generate fences only for SMP MTTCG guests Pranith Kumar
2016-05-31 18:46 ` [Qemu-devel] [RFC v2 PATCH 00/13] tcg: Add fence gen support Pranith Kumar
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