From 900cba8881b39dfbc7c8062098504ab93f5387a8 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Fri, 18 Dec 2009 10:31:31 +0100 Subject: [PATCH] xen: support CONFIG_MAXSMP The MAXSMP config option requires CPUMASK_OFFSTACK, which in turn requires we init the memory for the maps while we bring up the cpus. MAXSMP also increases NR_CPUS to 4096. This increase in size exposed an issue in the argument construction for multicalls from xen_flush_tlb_others. The args should only need space for the actual number of cpus. Also in 2.6.39 it exposes a bootup problem. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] set_cpu_sibling_map+0x123/0x30d ... Call Trace: [] ? xen_restore_fl_direct_reloc+0x4/0x4 [] xen_smp_prepare_cpus+0x36/0x135 .. CC: stable@kernel.org Signed-off-by: Andrew Jones [v2: Updated to compile on 3.0] [v3: Updated to compile when CONFIG_SMP is not defined] Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/mmu.c | 3 ++- arch/x86/xen/smp.c | 7 +++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index afe1d54f980c..673e968df3cf 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -59,6 +59,7 @@ #include #include #include +#include #include #include @@ -1231,7 +1232,7 @@ static void xen_flush_tlb_others(const struct cpumask *cpus, { struct { struct mmuext_op op; - DECLARE_BITMAP(mask, NR_CPUS); + DECLARE_BITMAP(mask, num_processors); } *args; struct multicall_space mcs; diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 41038c01de40..b4533a86d7e4 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -205,11 +205,18 @@ static void __init xen_smp_prepare_boot_cpu(void) static void __init xen_smp_prepare_cpus(unsigned int max_cpus) { unsigned cpu; + unsigned int i; xen_init_lock_cpu(0); smp_store_cpu_info(0); cpu_data(0).x86_max_cores = 1; + + for_each_possible_cpu(i) { + zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL); + zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL); + zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL); + } set_cpu_sibling_map(0); if (xen_smp_intr_init(0)) -- 2.20.1