[Qemu-devel] [question] the patch which affect performance of virtio-scsi

[Wangting (Kathy)]

Hi Paolo,

Recently I test IO performance with virtio-scsi, and find out that the patch of
"virtio-scsi: add support for the any_layout feature" affects IO performance of 
model
with 4KB 32iodepth sequence read.

Why cdb and sense is removed from the struct of VirtIOSCSICmdReq and 
VirtIOSCSICmdResp?
How do you consider the impact of the changes to the performance?
Although the latest version of qemu can optimize the performance by the way of 
reading merger,
I think the affect of this patch cannot be ignored.

Best wishes,

Ting