From: Christoph Hellwig <hch@infradead.org>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
peterx@redhat.com
Subject: Re: [PATCH 7/7] vfio/pci: Remove map-on-fault behavior
Date: Tue, 10 Aug 2021 11:11:49 +0200 [thread overview]
Message-ID: <YRJC1buKp67kGemh@infradead.org> (raw)
In-Reply-To: <162818330190.1511194.10498114924408843888.stgit@omen>
On Thu, Aug 05, 2021 at 11:08:21AM -0600, Alex Williamson wrote:
> +void vfio_pci_test_and_up_write_memory_lock(struct vfio_pci_device *vdev)
> +{
> + if (vdev->zapped_bars && __vfio_pci_memory_enabled(vdev)) {
> + WARN_ON(vfio_device_io_remap_mapping_range(&vdev->vdev,
> + VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_BAR0_REGION_INDEX),
> + VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_ROM_REGION_INDEX) -
> + VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_BAR0_REGION_INDEX)));
> + vdev->zapped_bars = false;
Doing actual work inside a WARN_ON is pretty nasty. Also the non-ONCE
version here will lead to massive log splatter if it actually hits.
I'd prefer something like:
loff_t start = VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_BAR0_REGION_INDEX);
loff_t end = VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_ROM_REGION_INDEX);
if (vdev->zapped_bars && __vfio_pci_memory_enabled(vdev)) {
if (!vfio_device_io_remap_mapping_range(&vdev->vdev, start,
end - start))
vdev->zapped_bars = false;
WARN_ON_ONCE(vdev->zapped_bars);
> vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> - vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
What is the story with this appearing earlier and disappearing here
again?
> +extern void vfio_pci_test_and_up_write_memory_lock(struct vfio_pci_device
> + *vdev);
No need for the extern.
next prev parent reply other threads:[~2021-08-10 9:12 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-05 17:06 [PATCH 0/7] vfio: device fd address space and vfio-pci mmap invalidation cleanup Alex Williamson
2021-08-05 17:07 ` [PATCH 1/7] vfio: Create vfio_fs_type with inode per device Alex Williamson
2021-08-10 8:43 ` Christoph Hellwig
2021-08-10 14:52 ` Alex Williamson
2021-08-10 14:57 ` Christoph Hellwig
2021-08-10 18:49 ` Peter Xu
2021-08-10 21:16 ` Alex Williamson
2021-08-10 22:18 ` Peter Xu
2021-08-05 17:07 ` [PATCH 2/7] vfio: Export unmap_mapping_range() wrapper Alex Williamson
2021-08-10 8:45 ` Christoph Hellwig
2021-08-10 18:56 ` Peter Xu
2021-08-05 17:07 ` [PATCH 3/7] vfio/pci: Use vfio_device_unmap_mapping_range() Alex Williamson
2021-08-06 1:04 ` Jason Gunthorpe
2021-08-06 20:17 ` Alex Williamson
2021-08-10 8:51 ` Christoph Hellwig
2021-08-10 11:57 ` Jason Gunthorpe
2021-08-10 12:55 ` Christoph Hellwig
2021-08-10 21:50 ` Alex Williamson
2021-08-11 11:57 ` Jason Gunthorpe
2021-08-10 8:53 ` Christoph Hellwig
2021-08-10 19:02 ` Peter Xu
2021-08-10 20:51 ` Alex Williamson
2021-08-10 18:48 ` Peter Xu
2021-08-10 19:59 ` Alex Williamson
2021-08-10 20:20 ` Peter Xu
2021-08-05 17:07 ` [PATCH 4/7] vfio,vfio-pci: Add vma to pfn callback Alex Williamson
2021-08-06 1:01 ` Jason Gunthorpe
2021-08-10 9:00 ` Christoph Hellwig
2021-08-10 9:00 ` Christoph Hellwig
2021-08-05 17:08 ` [PATCH 5/7] mm/interval_tree.c: Export vma interval tree iterators Alex Williamson
2021-08-05 17:08 ` [PATCH 6/7] vfio: Add vfio_device_io_remap_mapping_range() Alex Williamson
2021-08-10 9:04 ` Christoph Hellwig
2021-08-05 17:08 ` [PATCH 7/7] vfio/pci: Remove map-on-fault behavior Alex Williamson
2021-08-10 9:11 ` Christoph Hellwig [this message]
2021-08-10 15:04 ` Alex Williamson
2021-08-10 20:54 ` Peter Xu
2021-08-10 21:45 ` Alex Williamson
2021-08-10 22:27 ` Peter Xu
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=YRJC1buKp67kGemh@infradead.org \
--to=hch@infradead.org \
--cc=alex.williamson@redhat.com \
--cc=jgg@nvidia.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterx@redhat.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.