Re: [PATCH v5 06/10] vfio: selftests: Allow drivers to specify required region size

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Format string type mismatch for size_t variable breaks build on 32-bit architectures due to -Werror.
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commit 4aa3e6c27ff1032b734b64f7f2efb3d24be4bc07
Author: Jason Gunthorpe <jgg@ziepe.ca>

vfio: selftests: Allow drivers to specify required region size

This commit adds a region_size field to struct vfio_pci_driver_ops, allowing
drivers to declare their required DMA-mapped region size. It updates existing
drivers to pass the size of their state struct and removes the hardcoded
SZ_2M allocation.

> diff --git a/tools/testing/selftests/vfio/lib/iova_allocator.c b/tools/testing/selftests/vfio/lib/iova_allocator.c
> index 4a660f636f497..f70172f9ceb95 100644
> --- a/tools/testing/selftests/vfio/lib/iova_allocator.c
> +++ b/tools/testing/selftests/vfio/lib/iova_allocator.c
[ ... ]
> @@ -50,7 +52,10 @@ void iova_allocator_cleanup(struct iova_allocator *allocator)
>  iova_t iova_allocator_alloc(struct iova_allocator *allocator, size_t size)
>  {
>  	VFIO_ASSERT_GT(size, 0, "Invalid size arg, zero\n");
> -	VFIO_ASSERT_EQ(size & (size - 1), 0, "Invalid size arg, non-power-of-2\n");
> +
> +	VFIO_ASSERT_LE(size, rounddown_pow_of_two(SIZE_MAX),
> +		       "Invalid size arg, too large (%lu)\n", size);

[Severity: Low]
Will this cause a format string warning on 32-bit architectures?

Since size is of type size_t, which is typically unsigned int on 32-bit
builds, using %lu could trigger a build failure due to -Werror. Would it
be better to use %zu here?

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Sashiko AI review · https://sashiko.dev/#/patchset/0-v5-4cacb99249f6+1b4-mlx5st_jgg@nvidia.com?part=6