From: Julien Grall <julien.grall@arm.com>
To: Stefano Stabellini <sstabellini@kernel.org>
Cc: andre.przywara@arm.com, wei.chen@linaro.org, wei.liu2@citrix.com,
steve.capper@arm.com, xen-devel@lists.xen.org
Subject: Re: [PATCH v2 15/15] xen/arm: arm64: Document Cortex-A57 erratum 834220
Date: Mon, 30 May 2016 17:33:28 +0100 [thread overview]
Message-ID: <02bc0b0e-d1ce-5918-f562-8e10514c5b6a@arm.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1605301717080.3896@sstabellini-ThinkPad-X260>
On 30/05/2016 17:19, Stefano Stabellini wrote:
>> "Erratum #834220: Xen needs to check that the Stage 1 translation does not
>> generate a fault before handling Stage 2 fault. If it is a stage 1 translation
>> fault, return to the guest to let the project injecting the correct fault.
>>
>> XXX: This can be optimized to avoid some unnecessary translation."
>
> What about adding a lengthy and detailed description of the erratum
> elsewhere and just having a one liner at the call sites, such as:
I don't see any problem to have "lengthy" comment twice. It could
actually be 3 lines because the last one is a TODO.
I thought about merging some bits of do_trap_instr_abort_guest and
do_trap_data_abort_guest, but at first glance it is not that simple.
> /* Erratum #834220: check Stage1 translation does not generate faults first! */
>
> so that developers can easily grep for #834220 through the code to have
> the full explanation?
Where would you put the full explanation? do_trap_hypervisor does not
make sense because it does not deal with the erratum. When we will come
back in few months time, we will wonder why the comment is there.
Regards,
--
Julien Grall
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next prev parent reply other threads:[~2016-05-30 16:33 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-23 14:17 [PATCH v2 00/15] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
2016-05-23 14:17 ` [PATCH v2 01/15] xen/arm: Makefile: Sort the entries alphabetically Julien Grall
2016-05-23 14:17 ` [PATCH v2 02/15] xen/arm: Include the header asm-arm/system.h in asm-arm/page.h Julien Grall
2016-05-23 14:17 ` [PATCH v2 03/15] xen/arm: Add macros to handle the MIDR Julien Grall
2016-05-23 14:17 ` [PATCH v2 04/15] xen/arm: Add cpu_hwcap bitmap Julien Grall
2016-05-30 14:19 ` Stefano Stabellini
2016-05-23 14:17 ` [PATCH v2 05/15] xen/arm64: Add an helper to invalidate all instruction caches Julien Grall
2016-05-23 14:17 ` [PATCH v2 06/15] xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header Julien Grall
2016-05-23 14:17 ` [PATCH v2 07/15] xen/arm: arm64: Reserve a brk immediate to fault on purpose Julien Grall
2016-05-23 14:17 ` [PATCH v2 08/15] xen/arm: arm64: Add helpers to decode and encode branch instructions Julien Grall
2016-05-30 14:29 ` Stefano Stabellini
2016-05-23 14:17 ` [PATCH v2 09/15] xen/arm: Introduce alternative runtime patching Julien Grall
2016-05-23 14:17 ` [PATCH v2 10/15] xen/arm: Detect silicon revision and set cap bits accordingly Julien Grall
2016-05-30 15:02 ` Stefano Stabellini
2016-05-30 16:37 ` Julien Grall
2016-05-31 9:27 ` Stefano Stabellini
2016-05-31 10:36 ` Julien Grall
2016-06-01 9:46 ` Stefano Stabellini
2016-06-01 12:47 ` Julien Grall
2016-06-02 11:43 ` Julien Grall
2016-06-02 11:45 ` Julien Grall
2016-05-23 14:17 ` [PATCH v2 11/15] xen/arm: Document the errata implemented in Xen Julien Grall
2016-05-23 14:38 ` Andrew Cooper
2016-05-24 9:13 ` Julien Grall
2016-05-30 15:08 ` Stefano Stabellini
2016-05-23 14:17 ` [PATCH v2 12/15] xen/arm: arm64: Add Cortex-A53 cache errata workaround Julien Grall
2016-05-24 2:46 ` Chenxiao Zhao
2016-05-24 8:56 ` Julien Grall
2016-05-23 14:17 ` [PATCH v2 13/15] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround Julien Grall
2016-05-23 14:17 ` [PATCH v2 14/15] xen/arm: traps: Don't inject a fault if the translation VA -> IPA fails Julien Grall
2016-05-30 14:50 ` Stefano Stabellini
2016-05-23 14:17 ` [PATCH v2 15/15] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
2016-05-30 15:11 ` Stefano Stabellini
2016-05-30 16:15 ` Julien Grall
2016-05-30 16:19 ` Stefano Stabellini
2016-05-30 16:33 ` Julien Grall [this message]
2016-05-31 9:34 ` Stefano Stabellini
2016-05-31 10:39 ` Julien Grall
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