Commit c028dd6b authored May 22, 2015 by Radim Krčmář Committed by Paolo Bonzini May 28, 2015

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 KrÄmÃ¡Å™ <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 257b9a5f

arch/x86/kvm/lapic.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1594,6 +1594,7 @@ 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);
		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);

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