Messages in this thread | | | Subject | Re: [PATCH 3/6] x86: Add nopv parameter to disable PV extensions | From | Juergen Gross <> | Date | Mon, 24 Jun 2019 15:07:46 +0200 |
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On 23.06.19 15:01, 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 is already 'xen_nopv' parameter for XEN platform but not for > others. 'xen_nopv' can then be removed with this change. > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> > Cc: xen-devel@lists.xenproject.org > --- > Documentation/admin-guide/kernel-parameters.txt | 4 ++++ > arch/x86/kernel/cpu/hypervisor.c | 11 +++++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 138f666..b352f36 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -5268,6 +5268,10 @@ > improve timer resolution at the expense of processing > more timer interrupts. > > + nopv= [X86] > + Disables the PV optimizations forcing the guest to run > + as generic guest with no PV drivers. > + > xirc2ps_cs= [NET,PCMCIA] > Format: > <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] > diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c > index 479ca47..4f2c875 100644 > --- a/arch/x86/kernel/cpu/hypervisor.c > +++ b/arch/x86/kernel/cpu/hypervisor.c > @@ -85,10 +85,21 @@ static void __init copy_array(const void *src, void *target, unsigned int size) > to[i] = from[i]; > } > > +static bool nopv; > +static __init int xen_parse_nopv(char *arg)
You really don't want to use the "xen_" prefix here.
Juergen
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