Re: [Qemu-devel] [PATCH] Add HTTP protocol using curl v2

[Kevin Wolf <kwolf@redhat.com>]

Daniel P. Berrange schrieb:
> All I care about from libvirt POV, is that there is a way to give QEMU an 
> absolute file path for a disk, and guarentee that QEMU will treat this as
> a local file path, and not try any access protocols, other than 'open(2)'.
> Various options from this thread....
> 
>  - Treat any path starting with / as local file
>  - Allow file:  as a prefix
>  - Allow file:/// as a prefix, real URI style
>  - Add a protocol=file  flag to -drive
> 
> Pick one, pick several, suggest more. Any of these options would work as 
> far as I'm concerned, and we could easily support several. I think the
> first is desirable because that's the natural thing users will try when
> launching QEMU directly.

I think we all agree that file: is a reasonable option for libvirt which
covers all cases of colons (even relative paths starting with http:), so
let's take this one. If you want to magically do the right thing for
users invoking qemu manually, I think we should rather go for:

5) Treat anything as local file which has a protocol prefix that doesn't
match a known protocol

This would mean that vvfat:xyz uses the vvfat protocol, but foo:bar is a
local file because the protocol foo doesn't exist. I think this variant
is less confusing magic than checking for a completely unrelated
character like /.

Kevin