KVM: x86/xen: Add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery
This adds basic support for delivering 2 level event channels to a guest.
Initially, it only supports delivery via the IRQ routing table, triggered
by an eventfd. In order to do so, it has a kvm_xen_set_evtchn_fast()
function which will use the pre-mapped shared_info page if it already
exists and is still valid, while the slow path through the irqfd_inject
workqueue will remap the shared_info page if necessary.
It sets the bits in the shared_info page but not the vcpu_info; that is
deferred to __kvm_xen_has_interrupt() which raises the vector to the
appropriate vCPU.
Add a 'verbose' mode to xen_shinfo_test while adding test cases for this.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211210163625.2886-5-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 42bde45..3050601 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4188,7 +4188,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_XEN_HVM:
r = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR |
KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL |
- KVM_XEN_HVM_CONFIG_SHARED_INFO;
+ KVM_XEN_HVM_CONFIG_SHARED_INFO |
+ KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL;
if (sched_info_on())
r |= KVM_XEN_HVM_CONFIG_RUNSTATE;
break;