| Date | Sat, 1 Oct 2022 00:59:13 +0000 | Subject | [PATCH v4 30/32] KVM: SVM: Ignore writes to Remote Read Data on AVIC write traps | From | Sean Christopherson <> |
| |
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@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> --- 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 17e64b056e4e..953b1fd14b6d 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -631,6 +631,9 @@ 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; } -- 2.38.0.rc1.362.ged0d419d3c-goog
|