[PATCH v2] KVM: Check the allocation of pv cpu mask

[Haiwei Li]

From: Haiwei Li <lihai...@tencent.com>

check the allocation of per-cpu __pv_cpu_mask. Initialize ops only when
successful.
Signed-off-by: Haiwei Li <lihai...@tencent.com>
---
 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;
        return 0;
+
+zalloc_cpumask_fail:
+       kvm_free_pv_cpu_mask();
+       return -ENOMEM;
 }
 arch_initcall(kvm_alloc_cpumask);

--
2.18.4