KVM: introduce kvm_make_vcpus_request_mask() API

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>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6d6e79c59e68fa7fd5387f48814341082d6b8526..14e710d639c7f0949872ea3334bc3274248046ca 100644 (file)
--- 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 c7b2e927f69903c4eb8bb571282d7a5b7ca5ca27..b125d94307d2edbc49f684aacc507963f99b7157 100644 (file)
--- 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;
 }