Re: [Qemu-devel] [RFC 1/3] block: Add ImageRotationalInfo

[Kevin Wolf]

Am 24.05.2019 um 19:28 hat Max Reitz geschrieben:
> This enum indicates whether a file is stored on a rotating disk or a
> solid-state drive.  Drivers report it via the .bdrv_get_info() callback,
> and if they do not, the global bdrv_get_info() implementation
> automatically takes it from bs->file or bs->backing, if available.

Good that you wrote "bs->file or bs->backing" explicitly. Otherwise, I
might have missed that it begs one big question: What is the correct
answer for a qcow2 file that has bs->file on an SSD, but bs->backing on
a rotating disk?

I don't think there is a correct answer for the whole device, so maybe
this information shouldn't be per device in BlockDriverInfo, but per
block in bdrv_co_block_status() (optionally determined if the caller
requests it)?

Kevin