Re: [PATCH] KVM: Check the allocation of pv cpu mask
From: Paolo Bonzini
Date: Fri Sep 11 2020 - 12:10:11 EST
On 01/09/20 13:41, Haiwei Li wrote:
> From: Haiwei Li <lihaiwei@xxxxxxxxxxx>
>
> check the allocation of per-cpu __pv_cpu_mask. Initialize ops only when
> successful.
>
> Signed-off-by: Haiwei Li <lihaiwei@xxxxxxxxxxx>
> ---
> arch/x86/kernel/kvm.c | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> index 08320b0b2b27..a64b894eaac0 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 +791,20 @@ 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;
> + }
> }
>
> + apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
> + 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
>
Queued, thanks.
I am currently on leave so I am going through the patches and queuing
them, but I will only push kvm/next and kvm/queue next week. kvm/master
patches will be sent to Linus for the next -rc though.
Paolo