KVM: Boost vCPU candidate in user mode which is delivering interrupt

[linux-2.6-microblaze.git] / virt / kvm / kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 529cff1..2799c66 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3137,6 +3137,11 @@ static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu)
        return false;
 }
 
+bool __weak kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu)
+{
+       return false;
+}
+
 void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
 {
        struct kvm *kvm = me->kvm;
@@ -3170,7 +3175,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
                            !vcpu_dy_runnable(vcpu))
                                continue;
                        if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode &&
-                               !kvm_arch_vcpu_in_kernel(vcpu))
+                           !kvm_arch_dy_has_pending_interrupt(vcpu) &&
+                           !kvm_arch_vcpu_in_kernel(vcpu))
                                continue;
                        if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
                                continue;
@@ -4197,6 +4203,12 @@ static struct file_operations kvm_vm_fops = {
        KVM_COMPAT(kvm_vm_compat_ioctl),
 };
 
+bool file_is_kvm(struct file *file)
+{
+       return file && file->f_op == &kvm_vm_fops;
+}
+EXPORT_SYMBOL_GPL(file_is_kvm);
+
 static int kvm_dev_ioctl_create_vm(unsigned long type)
 {
        int r;
@@ -4620,24 +4632,26 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
        return 0;
 }
 
-/* Caller must hold slots_lock. */
-void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
-                              struct kvm_io_device *dev)
+int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
+                             struct kvm_io_device *dev)
 {
        int i, j;
        struct kvm_io_bus *new_bus, *bus;
 
+       lockdep_assert_held(&kvm->slots_lock);
+
        bus = kvm_get_bus(kvm, bus_idx);
        if (!bus)
-               return;
+               return 0;
 
-       for (i = 0; i < bus->dev_count; i++)
+       for (i = 0; i < bus->dev_count; i++) {
                if (bus->range[i].dev == dev) {
                        break;
                }
+       }
 
        if (i == bus->dev_count)
-               return;
+               return 0;
 
        new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1),
                          GFP_KERNEL_ACCOUNT);
@@ -4646,7 +4660,13 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
                new_bus->dev_count--;
                memcpy(new_bus->range + i, bus->range + i + 1,
                                flex_array_size(new_bus, range, new_bus->dev_count - i));
-       } else {
+       }
+
+       rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
+       synchronize_srcu_expedited(&kvm->srcu);
+
+       /* Destroy the old bus _after_ installing the (null) bus. */
+       if (!new_bus) {
                pr_err("kvm: failed to shrink bus, removing it completely\n");
                for (j = 0; j < bus->dev_count; j++) {
                        if (j == i)
@@ -4655,10 +4675,8 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
                }
        }
 
-       rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
-       synchronize_srcu_expedited(&kvm->srcu);
        kfree(bus);
-       return;
+       return new_bus ? 0 : -ENOMEM;
 }
 
 struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,