| Message ID | 20200925180738.4426-1-lihaiwei.kernel@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] KVM: Check the allocation of pv cpu mask | expand |
lihaiwei.kernel@gmail.com writes: > From: Haiwei Li <lihaiwei@tencent.com> > > check the allocation of per-cpu __pv_cpu_mask. > > Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> > Signed-off-by: Haiwei Li <lihaiwei@tencent.com> > --- > v1 -> v2: > * add CONFIG_SMP for kvm_send_ipi_mask_allbutself to prevent build error > v2 -> v3: > * always check the allocation of __pv_cpu_mask in kvm_flush_tlb_others > > arch/x86/kernel/kvm.c | 27 ++++++++++++++++++++++++--- > 1 file changed, 24 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index 9663ba31347c..1e5da6db519c 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -553,7 +553,6 @@ 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; I see that kvm_send_ipi_mask_allbutself() uses per CPU __pv_cpu_mask and kvm_send_ipi_mask doesn't but assigning send_IPI_mask here and send_IPI_mask_allbutself in kvm_alloc_cpumask() looks weird. Personally, I'd prefet to move apic->send_IPI_mask to kvm_alloc_cpumask() too (probably call kvm_setup_pv_ipi() and get rid of kvm_apic_init() completely). Alternatively, we can save the original apic->send_IPI_mask_allbutself value to a variable and call it from kvm_send_ipi_mask_allbutself() when __pv_cpu_mask wasn't allocated. > pr_info("setup PV IPIs\n"); > } > > @@ -619,6 +618,11 @@ static void kvm_flush_tlb_others(const struct cpumask *cpumask, > struct kvm_steal_time *src; > struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask); > > + if (unlikely(!flushmask)) { > + native_flush_tlb_others(cpumask, info); > + return; > + } > + > cpumask_copy(flushmask, cpumask); > /* > * We have to call flush only on online vCPUs. And > @@ -765,6 +769,14 @@ static __init int activate_jump_labels(void) > } > arch_initcall(activate_jump_labels); > > +static void kvm_free_cpumask(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; > @@ -783,11 +795,20 @@ 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 > return 0; > + > +zalloc_cpumask_fail: > + kvm_free_cpumask(); > + return -ENOMEM; > } > arch_initcall(kvm_alloc_cpumask);
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 9663ba31347c..1e5da6db519c 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -553,7 +553,6 @@ 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"); } @@ -619,6 +618,11 @@ static void kvm_flush_tlb_others(const struct cpumask *cpumask, struct kvm_steal_time *src; struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask); + if (unlikely(!flushmask)) { + native_flush_tlb_others(cpumask, info); + return; + } + cpumask_copy(flushmask, cpumask); /* * We have to call flush only on online vCPUs. And @@ -765,6 +769,14 @@ static __init int activate_jump_labels(void) } arch_initcall(activate_jump_labels); +static void kvm_free_cpumask(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; @@ -783,11 +795,20 @@ 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 return 0; + +zalloc_cpumask_fail: + kvm_free_cpumask(); + return -ENOMEM; } arch_initcall(kvm_alloc_cpumask);