Add a start_assignment hook to kvm_x86_ops, which is called when kvm_arch_start_assignment is done. The hook is required to update the wakeup vector of a sleeping vCPU when a device is assigned to the guest. Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Index: kvm/arch/x86/include/asm/kvm_host.h =================================================================== --- kvm.orig/arch/x86/include/asm/kvm_host.h +++ kvm/arch/x86/include/asm/kvm_host.h @@ -1322,6 +1322,7 @@ struct kvm_x86_ops { int (*update_pi_irte)(struct kvm *kvm, unsigned int host_irq, uint32_t guest_irq, bool set); + void (*start_assignment)(struct kvm *kvm); void (*apicv_post_state_restore)(struct kvm_vcpu *vcpu); bool (*dy_apicv_has_pending_interrupt)(struct kvm_vcpu *vcpu); Index: kvm/arch/x86/kvm/x86.c =================================================================== --- kvm.orig/arch/x86/kvm/x86.c +++ kvm/arch/x86/kvm/x86.c @@ -11295,7 +11295,8 @@ bool kvm_arch_can_dequeue_async_page_pre void kvm_arch_start_assignment(struct kvm *kvm) { - atomic_inc(&kvm->arch.assigned_device_count); + if (atomic_inc_return(&kvm->arch.assigned_device_count) == 1) + static_call_cond(kvm_x86_start_assignment)(kvm); } EXPORT_SYMBOL_GPL(kvm_arch_start_assignment); Index: kvm/arch/x86/include/asm/kvm-x86-ops.h =================================================================== --- kvm.orig/arch/x86/include/asm/kvm-x86-ops.h +++ kvm/arch/x86/include/asm/kvm-x86-ops.h @@ -99,6 +99,7 @@ KVM_X86_OP_NULL(post_block) KVM_X86_OP_NULL(vcpu_blocking) KVM_X86_OP_NULL(vcpu_unblocking) KVM_X86_OP_NULL(update_pi_irte) +KVM_X86_OP_NULL(start_assignment) KVM_X86_OP_NULL(apicv_post_state_restore) KVM_X86_OP_NULL(dy_apicv_has_pending_interrupt) KVM_X86_OP_NULL(set_hv_timer)