Haiwei Li <[email protected]> writes: > From: Haiwei Li <[email protected]> > > check the allocation of per-cpu __pv_cpu_mask. Initialize ops only when > successful. > > Signed-off-by: Haiwei Li <[email protected]> > --- > arch/x86/kernel/kvm.c | 24 ++++++++++++++++++++---- > 1 file changed, 20 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index 08320b0b2b27..d3c062e551d7 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -555,7 +555,6 @@ static void kvm_send_ipi_mask_allbutself(const > struct cpumask *mask, int vector) > static void kvm_setup_pv_ipi(void) > { > apic->send_IPI_mask = kvm_send_ipi_mask; > - apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself; > pr_info("setup PV IPIs\n"); > } > > @@ -654,7 +653,6 @@ static void __init kvm_guest_init(void) > } > > if (pv_tlb_flush_supported()) { > - pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others; > pv_ops.mmu.tlb_remove_table = tlb_remove_table; > pr_info("KVM setup pv remote TLB flush\n"); > } > @@ -767,6 +765,14 @@ static __init int activate_jump_labels(void) > } > arch_initcall(activate_jump_labels); > > +static void kvm_free_pv_cpu_mask(void) > +{ > + unsigned int cpu; > + > + for_each_possible_cpu(cpu) > + free_cpumask_var(per_cpu(__pv_cpu_mask, cpu)); > +} > + > static __init int kvm_alloc_cpumask(void) > { > int cpu; > @@ -785,11 +791,21 @@ static __init int kvm_alloc_cpumask(void) > > if (alloc) > for_each_possible_cpu(cpu) { > - zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask, > cpu), > - GFP_KERNEL, cpu_to_node(cpu)); > + if (!zalloc_cpumask_var_node( > + per_cpu_ptr(&__pv_cpu_mask, cpu), > + GFP_KERNEL, cpu_to_node(cpu))) > + goto zalloc_cpumask_fail; > } > > +#if defined(CONFIG_SMP) > + apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself; > +#endif > + pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
This is too late I'm afraid. If I'm not mistaken PV patching happens earlier, so .init.guest_late_init (kvm_guest_init()) is good and arch_initcall() is bad. Have you checked that with this patch kvm_flush_tlb_others() is still being called? Actually, there is no need to assign kvm_flush_tlb_others() so late. We can always check if __pv_cpu_mask was allocated and revert back to the architectural path if not. > return 0; > + > +zalloc_cpumask_fail: > + kvm_free_pv_cpu_mask(); > + return -ENOMEM; > } > arch_initcall(kvm_alloc_cpumask); > > -- > 2.18.4 > -- Vitaly
