Commit d22a81b3 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: Do not change ICR on write to APIC_SELF_IPI 



Emulating writes to SELF_IPI with a write to ICR has an unwanted side effect:
the value of ICR in vAPIC page gets changed.  The lists SELF_IPI as write-only,
with no associated MMIO offset, so any write should have no visible side
effect in the vAPIC page.

Reported-by: default avatarChao Gao <chao.gao@intel.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f66af9f2

arch/x86/kvm/lapic.c

+3 −4
Original line number Diff line number Diff line
@@ -2120,10 +2120,9 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) 
		break;



	case APIC_SELF_IPI:

		if (apic_x2apic_mode(apic)) {

			kvm_lapic_reg_write(apic, APIC_ICR,

					    APIC_DEST_SELF | (val & APIC_VECTOR_MASK));

		} else

		if (apic_x2apic_mode(apic))

			kvm_apic_send_ipi(apic, APIC_DEST_SELF | (val & APIC_VECTOR_MASK), 0);

		else

			ret = 1;

		break;

	default: