From af28dfacbe00d53df5dec2bf50640df33138b1fe Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Mon, 22 Jun 2020 12:08:30 -0400 Subject: [PATCH] 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 Message-Id: <20200622160830.426022-1-imammedo@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 34a7e0533dad..6dc177da19da 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2567,6 +2567,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) } memcpy(vcpu->arch.apic->regs, s->regs, sizeof(*s)); + apic->vcpu->kvm->arch.apic_map_dirty = true; kvm_recalculate_apic_map(vcpu->kvm); kvm_apic_set_version(vcpu); -- 2.20.1