[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2] xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> By default when CONFIG_XEN and CONFIG_XEN_PVHVM kernels are run, they will enable the PV extensions (drivers, interrupts, timers, etc) - which is perfect. However, in some cases (kexec not fully wokring, benchmarking) we want to disable Xen PV extensions. As such introduce the 'xen_nopv' parameter that will do it. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> --- [v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.] --- Documentation/kernel-parameters.txt | 4 ++++ arch/x86/xen/enlighten.c | 13 +++++++++++++ 2 files changed, 17 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1b9aa8..5dcfa6e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3691,6 +3691,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Disables the ticketlock slowpath using Xen PV optimizations. + xen_nopv [X86,XEN] + Disables the PV optimizations forcing the guest to run + as generic HVM 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/xen/enlighten.c b/arch/x86/xen/enlighten.c index e220197..7aa59ef 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1930,10 +1930,21 @@ static void __init xen_hvm_guest_init(void) #endif } +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) { uint32_t eax, ebx, ecx, edx, base; + if (xen_nopv) + return 0; + if (xen_pv_domain()) return 0; @@ -1953,6 +1964,8 @@ 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()) -- 1.7.7.6 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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