Drop writes to APIC_RRR, a.k.a. Remote Read Data Register, on AVIC
unaccelerated write traps. The register is read-only and isn't emulated
by KVM. Sending the register through kvm_apic_write_nodecode() will
result in screaming when x2APIC is enabled due to the unexpected failure
to retrieve the MSR (KVM expects that only "legal" accesses will trap).
Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode")
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/avic.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index dad5affe44c1..b2033a56010c 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -675,6 +675,9 @@ static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu)
case APIC_DFR:
avic_handle_dfr_update(vcpu);
break;
+ case APIC_RRR:
+ /* Ignore writes to Read Remote Data, it's read-only. */
+ return 1;
default:
break;
}
--
2.37.2.672.g94769d06f0-goog
