kvm: lapic: fix broken vcpu hotplug
authorIgor Mammedov <imammedo@redhat.com>
Mon, 22 Jun 2020 16:08:30 +0000 (12:08 -0400)
committerPaolo Bonzini <pbonzini@redhat.com>
Mon, 22 Jun 2020 16:48:44 +0000 (12:48 -0400)
commitaf28dfacbe00d53df5dec2bf50640df33138b1fe
tree8775738045780864fe015270ad6e02dd4ac394c1
parent49097762fa405cdc16f8f597f6d27c078d4a31e9
kvm: lapic: fix broken vcpu hotplug

Guest fails to online hotplugged CPU with error
  smpboot: do_boot_cpu failed(-1) to wakeup CPU#4

It's caused by the fact that kvm_apic_set_state(), which used to call
recalculate_apic_map() unconditionally and pulled hotplugged CPU into
apic map, is updating map conditionally on state changes.  In this case
the APIC map is not considered dirty and the is not updated.

Fix the issue by forcing unconditional update from kvm_apic_set_state(),
like it used to be.

Fixes: 4abaffce4d25a ("KVM: LAPIC: Recalculate apic map in batch")
Cc: stable@vger.kernel.org
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20200622160830.426022-1-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/lapic.c