RE: [PATCH v6 0/6] Fix double allocation in swiotlb_alloc()

[Michael Kelley]

From: Will Deacon <will@xxxxxxxxxx> Sent: Friday, March 8, 2024 7:28 AM
> 

[snip]

> 
> Changes since v5 include:
> 
>   - Rework the final patch to preserve page-alignment for streaming
>     requests without a DMA alignment mask
> 
>   - Added Reviewed-by tags from Michael
> 
> Cheers,
> 
> Will
> 

I've tested the full v6 of this series on an ARM64 VM in the Azure
public cloud with 64K page size, and swiotlb=force on the kernel
boot line.  The path exercised is the DMA Direct path on a synthetic
SCSI disk device with min_align_mask = 0xFFF.  I have a standalone
user-space test program using writev() to generate direct disk
I/Os with a variety of memory buffer alignments and physically
contiguous extents.  It's designed to test the paths through the
iovec level, scatter/gather lists, and the driver DMA descriptors
to make sure all is working correctly.

Prior to this patch series, some tests were failing with 64K page
size when swiotlb=force, but they are all working now.

Tested-by: Michael Kelley <mhklinux@xxxxxxxxxxx>