Once the vcpu file descriptors changed after confidential guest reset, the
local apic needs to be reinitialized. This change adds a callback from the
vcpu fd change notifiers to reinitialize local apic for kvm x86.

Signed-off-by: Ani Sinha <anisinha@redhat.com>
---
 hw/i386/kvm/apic.c              | 13 +++++++++++++
 include/hw/i386/apic_internal.h |  1 +
 2 files changed, 14 insertions(+)

diff --git a/hw/i386/kvm/apic.c b/hw/i386/kvm/apic.c
index 82355f0463..f6f8ac2764 100644
--- a/hw/i386/kvm/apic.c
+++ b/hw/i386/kvm/apic.c
@@ -229,6 +229,16 @@ static void kvm_apic_reset(APICCommonState *s)
     run_on_cpu(CPU(s->cpu), kvm_apic_put, RUN_ON_CPU_HOST_PTR(s));
 }
 
+static int apic_vcpufd_change_handler(NotifierWithReturn *n,
+                                      void *data, Error** errp) {
+    APICCommonState *s = container_of(n, APICCommonState,
+                                      vcpufd_change_notifier);
+
+    run_on_cpu(CPU(s->cpu), kvm_apic_put, RUN_ON_CPU_HOST_PTR(s));
+
+    return 0;
+}
+
 static void kvm_apic_realize(DeviceState *dev, Error **errp)
 {
     APICCommonState *s = APIC_COMMON(dev);
@@ -238,6 +248,9 @@ static void kvm_apic_realize(DeviceState *dev, Error **errp)
 
     assert(kvm_has_gsi_routing());
     msi_nonbroken = true;
+
+    s->vcpufd_change_notifier.notify = apic_vcpufd_change_handler;
+    kvm_vcpufd_add_change_notifier(&s->vcpufd_change_notifier);
 }
 
 static void kvm_apic_unrealize(DeviceState *dev)
diff --git a/include/hw/i386/apic_internal.h b/include/hw/i386/apic_internal.h
index 4a62fdceb4..ffe5815e7f 100644
--- a/include/hw/i386/apic_internal.h
+++ b/include/hw/i386/apic_internal.h
@@ -189,6 +189,7 @@ struct APICCommonState {
     hwaddr vapic_paddr; /* note: persistence via kvmvapic */
     bool legacy_instance_id;
     uint32_t extended_log_dest;
+    NotifierWithReturn vcpufd_change_notifier;
 };
 
 typedef struct VAPICState {
-- 
2.42.0