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authorRadim Krčmář <rkrcmar@redhat.com>2015-05-22 19:22:10 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2015-05-28 10:43:36 +0200
commitc028dd6bb648251b773f900f59e53544278b3b3c (patch)
tree719aa8e5f1e8d6ef4545cfbed953da92c77ee461 /arch/x86/kvm
parent257b9a5faab5849fa61f1a523b429dc279d33cc3 (diff)
downloadlinux-c028dd6bb648251b773f900f59e53544278b3b3c.tar.bz2
KVM: x86: preserve x2APIC LDR on INIT
Logical x2APIC stops working if we rewrite it with zeros. The best references are SDM April 2015: 10.12.10.1 Logical Destination Mode in x2APIC Mode [...], the LDR are initialized by hardware based on the value of x2APIC ID upon x2APIC state transitions. and SDM April 2015: 10.12.10.2 Deriving Logical x2APIC ID from the Local x2APIC ID The LDR initialization occurs whenever the x2APIC mode is enabled Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/lapic.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index c2a7d8a7a414..c789e00dfa8b 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1594,7 +1594,8 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
apic_set_reg(apic, APIC_DFR, 0xffffffffU);
apic_set_spiv(apic, 0xff);
apic_set_reg(apic, APIC_TASKPRI, 0);
- kvm_apic_set_ldr(apic, 0);
+ if (!apic_x2apic_mode(apic))
+ kvm_apic_set_ldr(apic, 0);
apic_set_reg(apic, APIC_ESR, 0);
apic_set_reg(apic, APIC_ICR, 0);
apic_set_reg(apic, APIC_ICR2, 0);