diff options
Diffstat (limited to 'arch/s390/kvm/priv.c')
| -rw-r--r-- | arch/s390/kvm/priv.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 30b24c42ef99..5beb7a4a11b3 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -102,7 +102,20 @@ static int handle_set_clock(struct kvm_vcpu *vcpu) return kvm_s390_inject_prog_cond(vcpu, rc); VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod); - kvm_s390_set_tod_clock(vcpu->kvm, >od); + /* + * To set the TOD clock the kvm lock must be taken, but the vcpu lock + * is already held in handle_set_clock. The usual lock order is the + * opposite. As SCK is deprecated and should not be used in several + * cases, for example when the multiple epoch facility or TOD clock + * steering facility is installed (see Principles of Operation), a + * slow path can be used. If the lock can not be taken via try_lock, + * the instruction will be retried via -EAGAIN at a later point in + * time. + */ + if (!kvm_s390_try_set_tod_clock(vcpu->kvm, >od)) { + kvm_s390_retry_instr(vcpu); + return -EAGAIN; + } kvm_s390_set_psw_cc(vcpu, 0); return 0; |