diff options
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index ba0492f9de65..ad8dc4ccdaab 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4898,6 +4898,18 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, BOOK3S_INTERRUPT_EXTERNAL, 0); else lpcr |= LPCR_MER; + } else { + /* + * L1's copy of L2's LPCR (vcpu->arch.vcore->lpcr) can get its MER bit + * unexpectedly set - for e.g. during NMI handling when all register + * states are synchronized from L0 to L1. L1 needs to inform L0 about + * MER=1 only when there are pending external interrupts. + * In the above if check, MER bit is set if there are pending + * external interrupts. Hence, explicity mask off MER bit + * here as otherwise it may generate spurious interrupts in L2 KVM + * causing an endless loop, which results in L2 guest getting hung. + */ + lpcr &= ~LPCR_MER; } } else if (vcpu->arch.pending_exceptions || vcpu->arch.doorbell_request || |