From: Nicolin Chen <nicolinc@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: "yong.wu@mediatek.com" <yong.wu@mediatek.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"will@kernel.org" <will@kernel.org>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
"jean-philippe@linaro.org" <jean-philippe@linaro.org>,
"jgg@nvidia.com" <jgg@nvidia.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"linux-mediatek@lists.infradead.org"
<linux-mediatek@lists.infradead.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>
Subject: Re: [PATCH v3 6/6] iommu: Propagate ret for a potential soft failure EINVAL
Date: Tue, 20 Sep 2022 13:39:30 -0700 [thread overview]
Message-ID: <YyolAgYPPH7Pnap6@Asurada-Nvidia> (raw)
In-Reply-To: <BN9PR11MB5276A69368B6E06E2C86EA058C4C9@BN9PR11MB5276.namprd11.prod.outlook.com>
On Tue, Sep 20, 2022 at 06:50:22AM +0000, Tian, Kevin wrote:
> External email: Use caution opening links or attachments
>
>
> > From: Nicolin Chen <nicolinc@nvidia.com>
> > Sent: Thursday, September 15, 2022 3:59 PM
> >
> > Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be
> > used to indicate that domain and device are incompatible by a caller that
> > treats it as a soft failure and tries attaching to another domain.
> >
> > Either mtk_iommu or virtio driver has a place that returns a hard failure
> > instead of the return value from the function call, where an incompatible
> > errno EINVAL could potentially occur.
>
> in both cases there is no EINVAL returned from the calling stack
>
> IMHO error propagation is the right way even w/o talking about EINVAL
> otherwise we may miss ENOMEM etc.
OK. I changed to:
The mtk_iommu and virtio drivers have places in the ->attach_dev callback
functions that return hardcode errnos instead of the returned values, but
callers of these ->attach_dv callback functions may care. Propagate them
directly without the extra conversions.
> > Propagate the real return value to not miss a potential soft failure.
> >
> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
>
> Apart from that comment,
>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Added this too. Thanks!
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2022-09-20 20:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-15 7:53 [PATCH v3 0/6] Define EINVAL as device/domain incompatibility Nicolin Chen
2022-09-15 7:53 ` [PATCH v3 3/6] iommu: Add return value rules to attach_dev op and APIs Nicolin Chen
2022-09-20 6:24 ` Tian, Kevin
2022-09-20 19:26 ` Nicolin Chen
2022-09-15 7:53 ` [PATCH v3 5/6] iommu: Use EINVAL for incompatible device/domain in ->attach_dev Nicolin Chen
2022-09-20 6:38 ` Tian, Kevin
2022-09-20 18:06 ` Jason Gunthorpe
2022-09-21 8:14 ` Tian, Kevin
2022-09-15 7:58 ` [PATCH v3 4/6] iommu: Regulate EINVAL in ->attach_dev callback functions Nicolin Chen
2022-09-20 6:29 ` Tian, Kevin
2022-09-20 16:08 ` Nicolin Chen
2022-09-15 7:58 ` [PATCH v3 6/6] iommu: Propagate ret for a potential soft failure EINVAL Nicolin Chen
2022-09-20 6:50 ` Tian, Kevin
2022-09-20 20:39 ` Nicolin Chen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YyolAgYPPH7Pnap6@Asurada-Nvidia \
--to=nicolinc@nvidia.com \
--cc=iommu@lists.linux.dev \
--cc=jean-philippe@linaro.org \
--cc=jgg@nvidia.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=matthias.bgg@gmail.com \
--cc=robin.murphy@arm.com \
--cc=virtualization@lists.linux-foundation.org \
--cc=will@kernel.org \
--cc=yong.wu@mediatek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox