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
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