Re: [PATCH v2 3/7] x86: Add nopv parameter to disable PV extensions

From: Juergen Gross
Date: Wed Jun 26 2019 - 05:38:43 EST


On 24.06.19 14:02, Zhenzhong Duan wrote:
In virtualization environment, PV extensions (drivers, interrupts,
timers, etc) are enabled in the majority of use cases which is the
best option.

However, in some cases (kexec not fully working, benchmarking)
we want to disable PV extensions. As such introduce the
'nopv' parameter that will do it.

There are guest types which just won't work without PV extensions,
like Xen PV, Xen PVH and jailhouse. add a "ignore_nopv" member to
struct hypervisor_x86 set to true for those guest types and call
the detect functions only if nopv is false or ignore_nopv is true.

There is already 'xen_nopv' parameter for XEN platform but not for
others. 'xen_nopv' can then be removed with this change.

Suggested-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx

Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Juergen