Re: [PATCH 2/2] hw/block/nvme: add write uncorrectable command

[Keith Busch]

On Wed, Feb 10, 2021 at 08:06:46AM +0100, Klaus Jensen wrote:
> From: Gollu Appalanaidu <anaidu.gollu@samsung.com>
> 
> Add support for marking blocks invalid with the Write Uncorrectable
> command. Block status is tracked in a (non-persistent) bitmap that is
> checked on all reads and written to on all writes. This is potentially
> expensive, so keep Write Uncorrectable disabled by default.

I really think attempting to emulate all these things is putting a
potentially unnecessary maintenance burden on this device.

The DULBE implementation started off similiar, but I suggested it
leverage support out of the backing file, and I feel it ended up better
for it.

But unlike punching and checking for holes, there's no filesystem
support for Write Uncorrectable in our qemu API, and that's probably
because this is kind of a niche feature. Is there a use case with a
real qemu guest wanting this?