diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 49 |
1 files changed, 46 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 01294a5099d..e87f6196d22 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -569,6 +569,45 @@ static void kvmppc_remove_runnable(struct kvmppc_vcore *vc, list_del(&vcpu->arch.run_list); } +static int kvmppc_grab_hwthread(int cpu) +{ + struct paca_struct *tpaca; + long timeout = 1000; + + tpaca = &paca[cpu]; + + /* Ensure the thread won't go into the kernel if it wakes */ + tpaca->kvm_hstate.hwthread_req = 1; + + /* + * If the thread is already executing in the kernel (e.g. handling + * a stray interrupt), wait for it to get back to nap mode. + * The smp_mb() is to ensure that our setting of hwthread_req + * is visible before we look at hwthread_state, so if this + * races with the code at system_reset_pSeries and the thread + * misses our setting of hwthread_req, we are sure to see its + * setting of hwthread_state, and vice versa. + */ + smp_mb(); + while (tpaca->kvm_hstate.hwthread_state == KVM_HWTHREAD_IN_KERNEL) { + if (--timeout <= 0) { + pr_err("KVM: couldn't grab cpu %d\n", cpu); + return -EBUSY; + } + udelay(1); + } + return 0; +} + +static void kvmppc_release_hwthread(int cpu) +{ + struct paca_struct *tpaca; + + tpaca = &paca[cpu]; + tpaca->kvm_hstate.hwthread_req = 0; + tpaca->kvm_hstate.kvm_vcpu = NULL; +} + static void kvmppc_start_thread(struct kvm_vcpu *vcpu) { int cpu; @@ -588,8 +627,7 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu) smp_wmb(); #if defined(CONFIG_PPC_ICP_NATIVE) && defined(CONFIG_SMP) if (vcpu->arch.ptid) { - tpaca->cpu_start = 0x80; - wmb(); + kvmppc_grab_hwthread(cpu); xics_wake_cpu(cpu); ++vc->n_woken; } @@ -639,7 +677,7 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc) struct kvm_vcpu *vcpu, *vcpu0, *vnext; long ret; u64 now; - int ptid; + int ptid, i; /* don't start if any threads have a signal pending */ list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) @@ -686,12 +724,17 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc) vc->napping_threads = 0; list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) kvmppc_start_thread(vcpu); + /* Grab any remaining hw threads so they can't go into the kernel */ + for (i = ptid; i < threads_per_core; ++i) + kvmppc_grab_hwthread(vc->pcpu + i); preempt_disable(); spin_unlock(&vc->lock); kvm_guest_enter(); __kvmppc_vcore_entry(NULL, vcpu0); + for (i = 0; i < threads_per_core; ++i) + kvmppc_release_hwthread(vc->pcpu + i); spin_lock(&vc->lock); /* disable sending of IPIs on virtual external irqs */ |