[patch 1/3] KVM: x86: add start_assignment hook to kvm_x86_ops

Marcelo Tosatti
2021-05-25T13:54:30Z

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@redhat.com>

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)