All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: mjrosato@linux.ibm.com, linux-doc@vger.kernel.org,
	airlied@linux.ie, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org, kwankhede@nvidia.com,
	vneethv@linux.ibm.com, agordeev@linux.ibm.com, hch@infradead.org,
	kvm@vger.kernel.org, corbet@lwn.net, pasic@linux.ibm.com,
	jgg@nvidia.com, borntraeger@linux.ibm.com,
	intel-gfx@lists.freedesktop.org, jjherne@linux.ibm.com,
	farman@linux.ibm.com, jchrist@linux.ibm.com, gor@linux.ibm.com,
	linux-s390@vger.kernel.org, hca@linux.ibm.com,
	freude@linux.ibm.com, rodrigo.vivi@intel.com,
	intel-gvt-dev@lists.freedesktop.org, akrowiak@linux.ibm.com,
	cohuck@redhat.com, oberpar@linux.ibm.com, svens@linux.ibm.com
Subject: Re: [Intel-gfx] [RFT][PATCH v2 1/9] vfio: Make vfio_unpin_pages() return void
Date: Tue, 5 Jul 2022 23:54:50 -0700	[thread overview]
Message-ID: <YsUxurAoglm7GmZP@infradead.org> (raw)
In-Reply-To: <20220706062759.24946-2-nicolinc@nvidia.com>

> +void vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
> +		      int npage)
>  {
>  	struct vfio_container *container;
>  	struct vfio_iommu_driver *driver;
> -	int ret;
>  
> -	if (!user_pfn || !npage || !vfio_assert_device_open(device))
> -		return -EINVAL;
> +	if (WARN_ON_ONCE(!user_pfn || !npage || !vfio_assert_device_open(device)))

This adds an overly long line.  Note that I think in general it is
better to have an individual WARN_ON per condition anyway, as that
allows to directly pinpoint what went wrong when it triggers.

> +	if (WARN_ON_ONCE(unlikely(!driver || !driver->ops->unpin_pages)))
> +		return;

I'd just skip this check an let it crash.  If someone calls unpin
on something totally random that wasn't even pinned we don't need to
handle that gracefully.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: kwankhede@nvidia.com, corbet@lwn.net, hca@linux.ibm.com,
	gor@linux.ibm.com, agordeev@linux.ibm.com,
	borntraeger@linux.ibm.com, svens@linux.ibm.com,
	zhenyuw@linux.intel.com, zhi.a.wang@intel.com,
	jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com,
	rodrigo.vivi@intel.com, tvrtko.ursulin@linux.intel.com,
	airlied@linux.ie, daniel@ffwll.ch, farman@linux.ibm.com,
	mjrosato@linux.ibm.com, pasic@linux.ibm.com,
	vneethv@linux.ibm.com, oberpar@linux.ibm.com,
	freude@linux.ibm.com, akrowiak@linux.ibm.com,
	jjherne@linux.ibm.com, alex.williamson@redhat.com,
	cohuck@redhat.com, jgg@nvidia.com, kevin.tian@intel.com,
	hch@infradead.org, jchrist@linux.ibm.com, kvm@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-s390@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org,
	intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [RFT][PATCH v2 1/9] vfio: Make vfio_unpin_pages() return void
Date: Tue, 5 Jul 2022 23:54:50 -0700	[thread overview]
Message-ID: <YsUxurAoglm7GmZP@infradead.org> (raw)
In-Reply-To: <20220706062759.24946-2-nicolinc@nvidia.com>

> +void vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
> +		      int npage)
>  {
>  	struct vfio_container *container;
>  	struct vfio_iommu_driver *driver;
> -	int ret;
>  
> -	if (!user_pfn || !npage || !vfio_assert_device_open(device))
> -		return -EINVAL;
> +	if (WARN_ON_ONCE(!user_pfn || !npage || !vfio_assert_device_open(device)))

This adds an overly long line.  Note that I think in general it is
better to have an individual WARN_ON per condition anyway, as that
allows to directly pinpoint what went wrong when it triggers.

> +	if (WARN_ON_ONCE(unlikely(!driver || !driver->ops->unpin_pages)))
> +		return;

I'd just skip this check an let it crash.  If someone calls unpin
on something totally random that wasn't even pinned we don't need to
handle that gracefully.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

  reply	other threads:[~2022-07-06  6:55 UTC|newest]

Thread overview: 120+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-06  6:27 [RFT][PATCH v2 0/9] Update vfio_pin/unpin_pages API Nicolin Chen
2022-07-06  6:27 ` Nicolin Chen
2022-07-06  6:27 ` [RFT][PATCH v2 1/9] vfio: Make vfio_unpin_pages() return void Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06  6:54   ` Christoph Hellwig [this message]
2022-07-06  6:54     ` Christoph Hellwig
2022-07-06 15:52     ` Nicolin Chen
2022-07-06 15:52       ` Nicolin Chen
2022-07-06 16:45   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 16:45     ` Jason Gunthorpe
2022-07-06 16:45     ` Jason Gunthorpe
2022-07-06 17:38   ` [Intel-gfx] " Kirti Wankhede
2022-07-06 17:38     ` Kirti Wankhede
2022-07-06 17:38     ` Kirti Wankhede
2022-07-07  8:42   ` [Intel-gfx] " Tian, Kevin
2022-07-07  8:42     ` Tian, Kevin
2022-07-07  8:42     ` Tian, Kevin
2022-07-07 17:12     ` Nicolin Chen
2022-07-07 17:12       ` Nicolin Chen
2022-07-07 19:22       ` [Intel-gfx] " Jason Gunthorpe
2022-07-07 19:22         ` Jason Gunthorpe
2022-07-07 19:22         ` Jason Gunthorpe
2022-07-07 19:38         ` Nicolin Chen
2022-07-07 19:38           ` Nicolin Chen
2022-07-06  6:27 ` [RFT][PATCH v2 2/9] vfio/ap: Pass in physical address of ind to ap_aqic() Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06 16:48   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 16:48     ` Jason Gunthorpe
2022-07-06 16:48     ` Jason Gunthorpe
2022-07-06  6:27 ` [RFT][PATCH v2 3/9] vfio/ccw: Only pass in contiguous pages Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06 17:05   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 17:05     ` Jason Gunthorpe
2022-07-06 17:05     ` Jason Gunthorpe
2022-07-08 20:25     ` Eric Farman
2022-07-08 20:25       ` Eric Farman
2022-07-08 20:25   ` Eric Farman
2022-07-08 20:25     ` Eric Farman
2022-07-06  6:27 ` [RFT][PATCH v2 4/9] vfio: Pass in starting IOVA to vfio_pin/unpin_pages API Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06  6:56   ` [Intel-gfx] " Christoph Hellwig
2022-07-06  6:56     ` Christoph Hellwig
2022-07-06 15:54     ` Nicolin Chen
2022-07-06 15:54       ` Nicolin Chen
2022-07-06 17:38   ` [Intel-gfx] " Kirti Wankhede
2022-07-06 17:38     ` Kirti Wankhede
2022-07-06 17:38     ` Kirti Wankhede
2022-07-06 17:49   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 17:49     ` Jason Gunthorpe
2022-07-06 17:49     ` Jason Gunthorpe
2022-07-06 17:58     ` Nicolin Chen
2022-07-06 17:58       ` Nicolin Chen
2022-07-06 19:21     ` Nicolin Chen
2022-07-06 19:21       ` Nicolin Chen
2022-07-07  8:46   ` [Intel-gfx] " Tian, Kevin
2022-07-07  8:46     ` Tian, Kevin
2022-07-07 17:04     ` Nicolin Chen
2022-07-07 17:04       ` Nicolin Chen
2022-07-08 20:27   ` Eric Farman
2022-07-08 20:27     ` Eric Farman
2022-07-06  6:27 ` [RFT][PATCH v2 5/9] vfio/ap: Remove redundant pfn Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06 17:55   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 17:55     ` Jason Gunthorpe
2022-07-06 17:55     ` Jason Gunthorpe
2022-07-06  6:27 ` [RFT][PATCH v2 6/9] vfio/ccw: Change pa_pfn list to pa_iova list Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06 17:59   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 17:59     ` Jason Gunthorpe
2022-07-06 17:59     ` Jason Gunthorpe
2022-07-08 20:26   ` Eric Farman
2022-07-08 20:26     ` Eric Farman
2022-07-06  6:27 ` [RFT][PATCH v2 7/9] vfio: Rename user_iova of vfio_dma_rw() Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06  6:57   ` [Intel-gfx] " Christoph Hellwig
2022-07-06  6:57     ` Christoph Hellwig
2022-07-06 18:15   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 18:15     ` Jason Gunthorpe
2022-07-06 18:15     ` Jason Gunthorpe
2022-07-07  8:47   ` [Intel-gfx] " Tian, Kevin
2022-07-07  8:47     ` Tian, Kevin
2022-07-07  8:47     ` Tian, Kevin
2022-07-06  6:27 ` [RFT][PATCH v2 8/9] vfio/ccw: Add kmap_local_page() for memcpy Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06 18:17   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 18:17     ` Jason Gunthorpe
2022-07-06 18:17     ` Jason Gunthorpe
2022-07-08 20:29   ` Eric Farman
2022-07-08 20:29     ` Eric Farman
2022-07-06  6:27 ` [RFT][PATCH v2 9/9] vfio: Replace phys_pfn with pages for vfio_pin_pages() Nicolin Chen
2022-07-06  6:27   ` Nicolin Chen
2022-07-06  6:57   ` [Intel-gfx] " Christoph Hellwig
2022-07-06  6:57     ` Christoph Hellwig
2022-07-06 17:39   ` [Intel-gfx] " Kirti Wankhede
2022-07-06 17:39     ` Kirti Wankhede
2022-07-06 17:39     ` Kirti Wankhede
2022-07-06 18:18   ` [Intel-gfx] " Jason Gunthorpe
2022-07-06 18:18     ` Jason Gunthorpe
2022-07-06 18:18     ` Jason Gunthorpe
2022-07-07  8:49   ` [Intel-gfx] " Tian, Kevin
2022-07-07  8:49     ` Tian, Kevin
2022-07-07  8:49     ` Tian, Kevin
2022-07-07 17:03     ` Nicolin Chen
2022-07-07 17:03       ` Nicolin Chen
2022-07-08 20:29   ` Eric Farman
2022-07-08 20:29     ` Eric Farman
2022-07-07  6:08 ` [Intel-gfx] [RFT][PATCH v2 0/9] Update vfio_pin/unpin_pages API Tian, Kevin
2022-07-07  6:08   ` Tian, Kevin
2022-07-07  6:08   ` Tian, Kevin
2022-07-07  6:17   ` Nicolin Chen
2022-07-07  6:17     ` Nicolin Chen
2022-07-08  7:24     ` [Intel-gfx] " Xu, Terrence
2022-07-08  7:24       ` Xu, Terrence
2022-07-08  7:24       ` Xu, Terrence
2022-07-08 20:20       ` Nicolin Chen
2022-07-08 20:20         ` Nicolin Chen
2022-07-08 20:30 ` Eric Farman
2022-07-08 20:30   ` Eric Farman
2022-07-08 20:31   ` Nicolin Chen
2022-07-08 20:31     ` Nicolin Chen

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=YsUxurAoglm7GmZP@infradead.org \
    --to=hch@infradead.org \
    --cc=agordeev@linux.ibm.com \
    --cc=airlied@linux.ie \
    --cc=akrowiak@linux.ibm.com \
    --cc=borntraeger@linux.ibm.com \
    --cc=cohuck@redhat.com \
    --cc=corbet@lwn.net \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=farman@linux.ibm.com \
    --cc=freude@linux.ibm.com \
    --cc=gor@linux.ibm.com \
    --cc=hca@linux.ibm.com \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=intel-gvt-dev@lists.freedesktop.org \
    --cc=jchrist@linux.ibm.com \
    --cc=jgg@nvidia.com \
    --cc=jjherne@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=kwankhede@nvidia.com \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=mjrosato@linux.ibm.com \
    --cc=nicolinc@nvidia.com \
    --cc=oberpar@linux.ibm.com \
    --cc=pasic@linux.ibm.com \
    --cc=rodrigo.vivi@intel.com \
    --cc=svens@linux.ibm.com \
    --cc=vneethv@linux.ibm.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.