From: Robin Murphy <robin.murphy@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>,
AngeloGioacchino Del Regno <kholk11@gmail.com>,
Will Deacon <will.deacon@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] arm64/io: Don't use WZR in writel
Date: Mon, 11 Feb 2019 16:37:22 +0000 [thread overview]
Message-ID: <0dcc636d-236f-6211-4bf4-5c20f2aeefc2@arm.com> (raw)
In-Reply-To: <235d20ef-3054-69d9-975d-25aebf32aad3@arm.com>
On 11/02/2019 14:59, Marc Zyngier wrote:
> On 11/02/2019 14:29, AngeloGioacchino Del Regno wrote:
>
> [...]
>
>> Also, just one more thing: yes this thing is going ARM64-wide and
>> - from my findings - it's targeting certain Qualcomm SoCs, but...
>> I'm not sure that only QC is affected by that, others may as well
>> have the same stupid bug.
>>
>
> At the moment, only QC SoCs seem to be affected, probably because
> everyone else has debugged their hypervisor (or most likely doesn't
> bother with shipping one).
>
> In all honesty, we need some information from QC here: which SoCs are
> affected, what is the exact nature of the bug, can it be triggered from
> EL0. Randomly papering over symptoms is not something I really like
> doing, and is likely to generate problems on unaffected systems.
And even if we *were* to just try papering over the observed extent of
the issue, I'd still be inclined to confine it to arm-smmu.c where the
impact is finite and minimal - of the 4 instances of writel(0) there, 3
of them don't care what the data is (so could just reuse the base
register or similar) and the other one already has a zero in a GPR to
hand by construction.
Robin.
next prev parent reply other threads:[~2019-02-11 16:37 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-09 18:34 [PATCH] arm64/io: Don't use WZR in writel AngeloGioacchino Del Regno
2019-02-11 10:57 ` Will Deacon
2019-02-11 11:52 ` Marc Zyngier
2019-02-11 14:29 ` AngeloGioacchino Del Regno
2019-02-11 14:59 ` Marc Zyngier
2019-02-11 16:15 ` AngeloGioacchino Del Regno
2019-02-11 16:37 ` Robin Murphy [this message]
2019-02-23 18:12 ` Bjorn Andersson
2019-02-23 18:37 ` Marc Zyngier
2019-02-24 3:53 ` Bjorn Andersson
2019-03-12 12:36 ` Marc Gonzalez
2019-03-18 16:04 ` Robin Murphy
2019-03-18 17:00 ` Russell King - ARM Linux admin
2019-03-18 17:11 ` Ard Biesheuvel
2019-03-18 17:19 ` Robin Murphy
2019-03-18 17:24 ` Robin Murphy
2019-03-19 11:45 ` Robin Murphy
2019-03-18 17:30 ` Marc Gonzalez
2019-03-18 17:59 ` Robin Murphy
-- strict thread matches above, loose matches on Subject: below --
2019-02-09 18:30 AngeloGioacchino Del Regno
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