Re: [PATCH v2 0/2] vhost-scsi: Fix IO hangs when using windows

Stefan Hajnoczi
2023-07-11T20:23:43Z

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On Sun, Jul 09, 2023 at 03:28:57PM -0500, Mike Christie wrote:
> The following patches were made over Linus's tree and fix an issue
> where windows guests will send iovecs with offset/lengths that result
> in IOs that are not aligned to 512. The LIO layer will then send them
> to Linux's FS/block layer but it requires 512 byte alignment, so
> depending on the FS/block driver being used we will get IO errors or
> hung IO.
>
> The following patches have vhost-scsi detect when windows sends these
> IOs and copy them to a bounce buffer. It then does some cleanup in
> the related code.

Hang on, virtio-scsi is a SCSI HBA and READs/WRITEs submitted must
follow the usual constraints on SCSI block limits. Would Windows send
mis-aligned I/O to a non-virtio-scsi SCSI HBA?

Are you sure this is not a bug in the Windows guest driver where block
limits are being misconfigured?

Stefan

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