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-rw-r--r--arch/powerpc/kvm/book3s_hv.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index fd4d978d5257..8d1a365b8edc 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1486,6 +1486,14 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
r = set_vpa(vcpu, &vcpu->arch.dtl, addr, len);
break;
case KVM_REG_PPC_TB_OFFSET:
+ /*
+ * POWER9 DD1 has an erratum where writing TBU40 causes
+ * the timebase to lose ticks. So we don't let the
+ * timebase offset be changed on P9 DD1. (It is
+ * initialized to zero.)
+ */
+ if (cpu_has_feature(CPU_FTR_POWER9_DD1))
+ break;
/* round up to multiple of 2^24 */
vcpu->arch.vcore->tb_offset =
ALIGN(set_reg_val(id, *val), 1UL << 24);
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