Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map

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From	Andrew Honig <ahonig@google.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map
Date	Fri, 01 Jul 2016 00:20:01 +0200
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> -
> -       new = kzalloc(sizeof(struct kvm_apic_map), GFP_KERNEL);
> +       u32 size, max_id = 255;
>
>         mutex_lock(&kvm->arch.apic_map_lock);
>
> +       kvm_for_each_vcpu(i, vcpu, kvm)
> +               if (kvm_apic_present(vcpu))
> +                       max_id = max(max_id, kvm_apic_id(vcpu->arch.apic));
> +
> +       /* kvm_apic_map_get_logical_dest() expects multiples of 16 */
> +       size = round_up(max_id + 1, 16);

Now that you're using the full range of apic_id values, could this
calculation overflow?  Perhaps max_id could be u64?

> +       new = kzalloc(sizeof(struct kvm_apic_map) +
> +                     sizeof(struct kvm_lapic) * size, GFP_KERNEL);
> +
>         if (!new)
>                 goto out;
>

Thread

[PATCH v1 00/11] KVM: x86: break the xAPIC barrier Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
  [PATCH v1 06/11] KVM: x86: use hardware-compatible format for APIC ID register Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:40 +0200
      Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 15:20 +0200
        Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 16:20 +0200
          Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 17:00 +0200
            Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 17:10 +0200
              Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 18:00 +0200
                Re: [PATCH v1 06/11] KVM: x86: use hardware-compatible format for  APIC ID register Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 18:40 +0200
  [PATCH v1 10/11] KVM: x86: add KVM_CAP_X2APIC_API Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 10/11] KVM: x86: add KVM_CAP_X2APIC_API Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:30 +0200
      Re: [PATCH v1 10/11] KVM: x86: add KVM_CAP_X2APIC_API Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 15:30 +0200
    Re: [PATCH v1 10/11] KVM: x86: add KVM_CAP_X2APIC_API David Matlack <dmatlack@google.com> - 2016-07-01 20:20 +0200
      Re: [PATCH v1 10/11] KVM: x86: add KVM_CAP_X2APIC_API Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 20:40 +0200
  [PATCH v1 04/11] KVM: x86: use u16 for logical VCPU mask in lapic Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 04/11] KVM: x86: use u16 for logical VCPU mask in lapic Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:20 +0200
      Re: [PATCH v1 04/11] KVM: x86: use u16 for logical VCPU mask in lapic Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 14:50 +0200
        Re: [PATCH v1 04/11] KVM: x86: use u16 for logical VCPU mask in lapic Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 16:20 +0200
  [PATCH v1 07/11] KVM: VMX: optimize APIC ID read with APICv Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
  [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Andrew Honig <ahonig@google.com> - 2016-07-01 00:20 +0200
      Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:50 +0200
        Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 14:50 +0200
          Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 16:10 +0200
            Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 16:40 +0200
              Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 17:10 +0200
                Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 17:20 +0200
                Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 18:00 +0200
                Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 18:40 +0200
                Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 17:40 +0200
    Re: [PATCH v1 03/11] KVM: x86: dynamic kvm_apic_map Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 09:40 +0200
  [PATCH v1 01/11] KVM: x86: bump KVM_SOFT_MAX_VCPUS to 240 Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 01/11] KVM: x86: bump KVM_SOFT_MAX_VCPUS to 240 Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:50 +0200
  [PATCH v1 05/11] KVM: x86: use generic function for MSI parsing Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
  [PATCH v1 11/11] KVM: x86: bump MAX_VCPUS to 288 Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 11/11] KVM: x86: bump MAX_VCPUS to 288 Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:50 +0200
  [PATCH v1 09/11] KVM: x86: reset lapic base in kvm_lapic_reset Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 09/11] KVM: x86: reset lapic base in kvm_lapic_reset Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:50 +0200
  [PATCH v1 02/11] KVM: x86: add kvm_apic_map_get_dest_lapic Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200
    Re: [PATCH v1 02/11] KVM: x86: add kvm_apic_map_get_dest_lapic Paolo Bonzini <pbonzini@redhat.com> - 2016-07-01 10:00 +0200
      Re: [PATCH v1 02/11] KVM: x86: add kvm_apic_map_get_dest_lapic Radim Krčmář <rkrcmar@redhat.com> - 2016-07-01 14:50 +0200
  [PATCH v1 08/11] KVM: x86: directly call recalculate_apic_map on lapic restore Radim Krčmář <rkrcmar@redhat.com> - 2016-06-30 23:00 +0200

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