From e664376f21fc892ac0014d24ab48155115d8c79e Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Thu, 1 Sep 2011 09:48:27 -0400 Subject: [PATCH] xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead. commit ed467e69f16e6b480e2face7bc5963834d025f91 upstream. We have hit a couple of customer bugs where they would like to use those parameters to run an UP kernel - but both of those options turn of important sources of interrupt information so we end up not being able to boot. The correct way is to pass in 'dom0_max_vcpus=1' on the Xen hypervisor line and the kernel will patch itself to be a UP kernel. Fixes bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=637308 Acked-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Paul Gortmaker --- arch/x86/xen/smp.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index d2dfbf500fc8..9aac865f9bde 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -31,6 +31,7 @@ #include #include +#include #include "xen-ops.h" #include "mmu.h" @@ -181,6 +182,15 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus) { unsigned cpu; + if (skip_ioapic_setup) { + char *m = (max_cpus == 0) ? + "The nosmp parameter is incompatible with Xen; " \ + "use Xen dom0_max_vcpus=1 parameter" : + "The noapic parameter is incompatible with Xen"; + + xen_raw_printk(m); + panic(m); + } xen_init_lock_cpu(0); smp_store_cpu_info(0); -- 2.39.5