From 8d693b911bb9c57009c24cb1772d205b84c7985c Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 11 Jul 2014 11:51:35 -0400 Subject: xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests. By default when CONFIG_XEN and CONFIG_XEN_PVHVM kernels are run, they will enable the PV extensions (drivers, interrupts, timers, etc) - which is the best option for the majority of use cases. However, in some cases (kexec not fully working, benchmarking) we want to disable Xen PV extensions. As such introduce the 'xen_nopv' parameter that will do it. This parameter is intended only for HVM guests as the Xen PV guests MUST boot with PV extensions. However, even if you use 'xen_nopv' on Xen PV guests it will be ignored. Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: David Vrabel --- [v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.] [v3: Add Reviewed-by] [v4: Clarify that this is only for HVM guests] --- arch/x86/xen/enlighten.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'arch/x86/xen/enlighten.c') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index ffb101e..eb82239 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1826,8 +1826,19 @@ static void __init xen_hvm_guest_init(void) xen_hvm_init_mmu_ops(); } +static bool xen_nopv = false; +static __init int xen_parse_nopv(char *arg) +{ + xen_nopv = true; + return 0; +} +early_param("xen_nopv", xen_parse_nopv); + static uint32_t __init xen_hvm_platform(void) { + if (xen_nopv) + return 0; + if (xen_pv_domain()) return 0; @@ -1836,6 +1847,8 @@ static uint32_t __init xen_hvm_platform(void) bool xen_hvm_need_lapic(void) { + if (xen_nopv) + return false; if (xen_pv_domain()) return false; if (!xen_hvm_domain()) -- cgit v1.1