If KVM_SET_MSR firstly enables and then disables x2APIC, make sure
APIC_ID is actually updated correctly, since bits and offset differ from
xAPIC and x2APIC.
Currently this is not handled correctly, as kvm_set_apic_base() will
have msr_info->host_initiated, so switching from x2APIC to xAPIC won't
fail, but kvm_lapic_set_base() does not handle the case.
Fixes: 8d860bbeedef ("kvm: vmx: Basic APIC virtualization controls have three settings")
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 4efdb4a4d72c..df0a50099aa2 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2394,8 +2394,12 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
}
}
- if (((old_value ^ value) & X2APIC_ENABLE) && (value & X2APIC_ENABLE))
- kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
+ if ((old_value ^ value) & X2APIC_ENABLE) {
+ if (value & X2APIC_ENABLE)
+ kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
+ else
+ kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
+ }
if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) {
kvm_vcpu_update_apicv(vcpu);
--
2.31.1
