Warner Losh 9a5a5c1576 pvscsi: Advertise maxio of 256k. ...

While the PV SCSI SG list can handle 512k of SG entries, it can only do
so for I/O that's aligned to 4k or better. newfs_msdos does unaligned
I/O, so triggers too long for host errors in cam when a 512k I/O is
attempted. Prefer power of 2 256k to the absolute maximum 508k, though
that can be revisited should the latter show to give significant
performance improvement.

MFC After:		3 days
Tested by:		darius on discord (508k version of patch)
Sponsored by:		Netflix

2021-04-22 11:23:29 -06:00

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pvscsi

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vmci

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vmxnet3

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