On 13/11/2019 13:47, Paul Durrant wrote:
> ...when their values are larger than the per-domain configured limits.
>
> Signed-off-by: Paul Durrant <[email protected]>
> ---
> After mining through commits it is still unclear to me exactly when Xen
> stopped honouring the global values, but I really think this commit should
> be back-ported to stable trees as it was a behavioural change that can
> cause domUs to fail in non-obvious ways.

-1.  Overriding toolstack settings like this is the same kind of "bad"
as silently converting HAP => Shadow.

In particular, this breaks one of points of the original per-domain work
to deliberately allow stub xenstored to be configured with tiny
grant/maptrack tables.

You also break the setting of these parameters in xl.conf.

I'm not defending how the interface changed subtly/unexpected; that was
bad and we should have done better, but this change is just as bad in
the opposite direction.

The way to fix this is to plumb the Xen default parameters though so
that, in the absence of any explicit configuration (vm.cfg or xl.conf),
libxl can then use "xen cmdline" as a source of configuration, before
falling back to hardcoded numbers.

~Andrew

_______________________________________________
Xen-devel mailing list
[email protected]
https://lists.xenproject.org/mailman/listinfo/xen-devel

Reply via email to