Re: [PATCH] blkio: Respect memory-alignment for bounce buffer allocations

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Wed, Jan 31, 2024 at 06:31:40PM +0100, Kevin Wolf wrote:
> blkio_alloc_mem_region() requires that the requested buffer size is a
> multiple of the memory-alignment property. If it isn't, the allocation
> fails with a return value of -EINVAL.
> 
> Fix the call in blkio_resize_bounce_pool() to make sure the requested
> size is properly aligned.
> 
> I observed this problem with vhost-vdpa, which requires page aligned
> memory. As the virtio-blk device behind it still had 512 byte blocks, we
> got bs->bl.request_alignment = 512, but actually any request that needed
> a bounce buffer and was not aligned to 4k would fail without this fix.
> 
> Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/blkio.c | 3 +++
>  1 file changed, 3 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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