Awesome, thanks!

On Wed, Apr 29, 2020 at 10:55 PM Andrew Cooper <andrew.cooper3@citrix.com>
wrote:

> On 29/04/2020 18:17, Ayush Dosaj wrote:
> > Hi Xen development team,
> >
> > I am Ayush. I compiled Xen Hypervisor from source on Ubuntu 20.04
> > machine running on an intel-i9 CPU.
> > I am getting compilation error due to the following two flags.
> > Error: error: ‘-mindirect-branch’ and ‘-fcf-protection’ are not
> compatible.
> >
> > Complete Error logs can be found at
> https://paste.ubuntu.com/p/xvvyPnhW5c/
> >
> > And when I compiled Xen commenting the two flags in Rules.mk file, it
> > compiles and installs properly but on boot-up i see a blank black screen
> > and i am stuck there.
>
> That is a GCC bug (these options are actually fine in combination).  It
> got fixed earlier today in master, and backported for GCC 9.4
>
> You can work around it by appending -fcf-protection=none to CFLAGS
>
> I wouldn't try editing the logic around -mindirect-branch, as that is
> related to retpoline safety for Spectre v2, and probably relies on the
> build matching the code.
>
> ~Andrew
>


-- 
Ayush Dosaj
VIT Vellore