Re: [PATCH RFC v3 12/12] hw/block/nvme: add support for the format nvm command

[Keith Busch <kbusch@kernel.org>]

On Wed, Feb 17, 2021 at 09:26:37AM +0100, Klaus Jensen wrote:
> On Feb 16 15:16, Keith Busch wrote:
> > On Mon, Feb 15, 2021 at 12:02:40AM +0100, Klaus Jensen wrote:
> > > From: Minwoo Im <minwoo.im@samsung.com>
> > > 
> > > Format NVM admin command can make a namespace or namespaces to be
> > > with different LBA size and metadata size with protection information
> > > types.
> > > 
> > > This patch introduces Format NVM command with LBA format, Metadata, and
> > > Protection Information for the device. The secure erase operation things
> > > are yet to be added.
> > > 
> > > The parameter checks inside of this patch has been referred from
> > > Keith's old branch.
> > 
> > Oh, and here's the format command now, so my previous comment on patch
> > 11 doesn't matter.
> > 
> > > +struct nvme_aio_format_ctx {
> > > +    NvmeRequest   *req;
> > > +    NvmeNamespace *ns;
> > > +
> > > +    /* number of outstanding write zeroes for this namespace */
> > > +    int *count;
> > 
> > Shouldn't this count be the NvmeRequest's opaque value?
> 
> That is already occupied by `num_formats` which tracks formats of
> individual namespaces. `count` is for outstanding write zeroes on one
> particular namespace.

But why are they tracked separately? It looks like we only care about
the number of outstanding zero-out commands. It doesn't matter how that
number is spread across multiple namespaces.