[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH for-4.13 2/2] xen/nospec: Introduce CONFIG_SPECULATIVE_BRANCH_HARDEN and disable it



Hi Jan,

On 01/10/2019 10:22, Jan Beulich wrote:
On 01.10.2019 11:17, Julien Grall wrote:
On 01/10/2019 00:21, Andrew Cooper wrote:
On 30/09/2019 21:17, Julien Grall wrote:
My worry is this gate config gate nothing on Arm so the user may have
a false sense that it can be used (even though it is clearly BROKEN).

Also the name is quite close to the CONFIG_HARDEN_PREDICTOR on Arm and
may confuse user. Although, I don't have a better name so far :/

The "depends on BROKEN" means it will never show up to a user in
menuconfig, which is why it was only CC to x86, and not to rest.

What's the long term plan for this option? Are you planning to remove it
completely or just the dependencies on BROKEN?

My concern is if this option will ever become selectable then it will not doing
what's expected on Arm.

So, even if in principle it is arch agnostic, it feels to me this option should
better be implemented in x86/Kconfig.

I don't think so, no. When BROKEN is to be removed, it ought to be
replaced by a suitable "depends on HAVE_*", which Arm could choose
to not select.

So there are an expectation this option will be used by common code in the 
future?

Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.