From ea5b8f73933e34d2b47a65284c46d26d49e7edb9 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Tue, 26 Oct 2010 17:28:33 +0100 Subject: [PATCH] xen: initialize cpu masks for pv guests in xen_smp_init Pv guests don't have ACPI and need the cpu masks to be set correctly as early as possible so we call xen_fill_possible_map from xen_smp_init. On the other hand the initial domain supports ACPI so in this case we skip xen_fill_possible_map and rely on it. However Xen might limit the number of cpus usable by the domain, so we filter those masks during smp initialization using the VCPUOP_is_up hypercall. It is important that the filtering is done before xen_setup_vcpu_info_placement. Signed-off-by: Stefano Stabellini --- arch/x86/xen/smp.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 138676781dd4..834dfeb54e31 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -28,6 +28,7 @@ #include #include +#include #include #include @@ -156,6 +157,25 @@ static void __init xen_fill_possible_map(void) { int i, rc; + if (xen_initial_domain()) + return; + + for (i = 0; i < nr_cpu_ids; i++) { + rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); + if (rc >= 0) { + num_processors++; + set_cpu_possible(i, true); + } + } +} + +static void __init xen_filter_cpu_maps(void) +{ + int i, rc; + + if (!xen_initial_domain()) + return; + num_processors = 0; disabled_cpus = 0; for (i = 0; i < nr_cpu_ids; i++) { @@ -179,6 +199,7 @@ static void __init xen_smp_prepare_boot_cpu(void) old memory can be recycled */ make_lowmem_page_readwrite(xen_initial_gdt); + xen_filter_cpu_maps(); xen_setup_vcpu_info_placement(); } @@ -195,8 +216,6 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus) if (xen_smp_intr_init(0)) BUG(); - xen_fill_possible_map(); - if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL)) panic("could not allocate xen_cpu_initialized_map\n"); @@ -487,5 +506,6 @@ static const struct smp_ops xen_smp_ops __initdata = { void __init xen_smp_init(void) { smp_ops = xen_smp_ops; + xen_fill_possible_map(); xen_init_spinlocks(); } -- 2.34.1