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    Subject[PATCH v4 5/8] KVM: introduce kvm_make_vcpus_request_mask() API
    Date
    Hyper-V style PV TLB flush hypercalls inmplementation will use this API.
    To avoid memory allocation in CONFIG_CPUMASK_OFFSTACK case add
    cpumask_var_t argument.

    Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
    ---
    include/linux/kvm_host.h | 3 +++
    virt/kvm/kvm_main.c | 34 ++++++++++++++++++++++++++--------
    2 files changed, 29 insertions(+), 8 deletions(-)

    diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
    index 6d6e79c59e68..14e710d639c7 100644
    --- a/include/linux/kvm_host.h
    +++ b/include/linux/kvm_host.h
    @@ -730,6 +730,9 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);

    void kvm_flush_remote_tlbs(struct kvm *kvm);
    void kvm_reload_remote_mmus(struct kvm *kvm);
    +
    +bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
    + unsigned long *vcpu_bitmap, cpumask_var_t tmp);
    bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);

    long kvm_arch_dev_ioctl(struct file *filp,
    diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
    index c7b2e927f699..b125d94307d2 100644
    --- a/virt/kvm/kvm_main.c
    +++ b/virt/kvm/kvm_main.c
    @@ -203,29 +203,47 @@ static inline bool kvm_kick_many_cpus(const struct cpumask *cpus, bool wait)
    return true;
    }

    -bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
    +bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
    + unsigned long *vcpu_bitmap, cpumask_var_t tmp)
    {
    int i, cpu, me;
    - cpumask_var_t cpus;
    - bool called;
    struct kvm_vcpu *vcpu;
    -
    - zalloc_cpumask_var(&cpus, GFP_ATOMIC);
    + bool called;

    me = get_cpu();
    +
    kvm_for_each_vcpu(i, vcpu, kvm) {
    + if (!test_bit(i, vcpu_bitmap))
    + continue;
    +
    kvm_make_request(req, vcpu);
    cpu = vcpu->cpu;

    if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu))
    continue;

    - if (cpus != NULL && cpu != -1 && cpu != me &&
    + if (tmp != NULL && cpu != -1 && cpu != me &&
    kvm_request_needs_ipi(vcpu, req))
    - __cpumask_set_cpu(cpu, cpus);
    + __cpumask_set_cpu(cpu, tmp);
    }
    - called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT));
    +
    + called = kvm_kick_many_cpus(tmp, !!(req & KVM_REQUEST_WAIT));
    put_cpu();
    +
    + return called;
    +}
    +
    +bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
    +{
    + cpumask_var_t cpus;
    + bool called;
    + static unsigned long vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)]
    + = {[0 ... BITS_TO_LONGS(KVM_MAX_VCPUS)-1] = ULONG_MAX};
    +
    + zalloc_cpumask_var(&cpus, GFP_ATOMIC);
    +
    + called = kvm_make_vcpus_request_mask(kvm, req, vcpu_bitmap, cpus);
    +
    free_cpumask_var(cpus);
    return called;
    }
    --
    2.14.3
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