Re: [PATCH v4.14.y 2/3] vfio-pci: Fault mmaps to enable vma tracking

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Sep 08, 2020 at 01:47:06AM +0530, Ajay Kaher wrote:
> From: Alex Williamson <alex.williamson@redhat.com>
> 
> commit 11c4cd07ba111a09f49625f9e4c851d83daf0a22 upstream.
> 
> Rather than calling remap_pfn_range() when a region is mmap'd, setup
> a vm_ops handler to support dynamic faulting of the range on access.
> This allows us to manage a list of vmas actively mapping the area that
> we can later use to invalidate those mappings.  The open callback
> invalidates the vma range so that all tracking is inserted in the
> fault handler and removed in the close handler.
> 
> Reviewed-by: Peter Xu <peterx@redhat.com>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> [Ajay: Regenerated the patch for v4.14]
> Signed-off-by: Ajay Kaher <akaher@vmware.com>
> ---
>  drivers/vfio/pci/vfio_pci.c         | 75 ++++++++++++++++++++++++++++++++++++-
>  drivers/vfio/pci/vfio_pci_private.h |  7 ++++
>  2 files changed, 80 insertions(+), 2 deletions(-)

Oops, nope, this patch breaks the build:

drivers/vfio/pci/vfio_pci.c:1183:11: error: initialization of \u2018int (*)(struct vm_fault *)\u2019 from incompatible pointer type \u2018int (*)(struct vm_area_struct *, struct vm_fault *)\u2019 [-Werror=incompatible-pointer-types]
 1183 |  .fault = vfio_pci_mmap_fault,
      |           ^~~~~~~~~~~~~~~~~~~
drivers/vfio/pci/vfio_pci.c:1183:11: note: (near initialization for \u2018vfio_pci_mmap_ops.fault\u2019)
cc1: some warnings being treated as errors

Did you test this?

Please fix up and resend the whole series for 4.14.y

thanks,

greg k-h