@@ -675,6 +675,17 @@ static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
vcpu->arch.dtl.dirty = true;
}
+/* See if there is a doorbell interrupt pending for a vcpu */
+static bool kvmppc_doorbell_pending(struct kvm_vcpu *vcpu)
+{
+ int thr;
+ struct kvmppc_vcore *vc;
+
+ vc = vcpu->arch.vcore;
+ thr = vcpu->vcpu_id - vc->first_vcpuid;
+ return !!(vc->dpdes & (1 << thr));
+}
+
static bool kvmppc_power8_compatible(struct kvm_vcpu *vcpu)
{
if (vcpu->arch.vcore->arch_compat >= PVR_ARCH_207)
@@ -2660,6 +2671,15 @@ static void shrink_halt_poll_ns(struct kvmppc_vcore *vc)
vc->halt_poll_ns /= halt_poll_ns_shrink;
}
+static bool kvmppc_vcpu_woken(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.pending_exceptions || vcpu->arch.prodded ||
+ kvmppc_doorbell_pending(vcpu))
+ return true;
+
+ return false;
+}
+
/*
* Check to see if any of the runnable vcpus on the vcore have pending
* exceptions or are no longer ceded
@@ -2670,8 +2690,7 @@ static int kvmppc_vcore_check_block(struct kvmppc_vcore *vc)
int i;
for_each_runnable_thread(i, vcpu, vc) {
- if (vcpu->arch.pending_exceptions || !vcpu->arch.ceded ||
- vcpu->arch.prodded)
+ if (!vcpu->arch.ceded || kvmppc_vcpu_woken(vcpu))
return 1;
}
@@ -2857,7 +2876,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
break;
n_ceded = 0;
for_each_runnable_thread(i, v, vc) {
- if (!v->arch.pending_exceptions && !v->arch.prodded)
+ if (!kvmppc_vcpu_woken(v))
n_ceded += v->arch.ceded;
else
v->arch.ceded = 0;
It is possible, through a narrow race condition, for a VCPU to exit the guest with a H_CEDE hypercall while it has a doorbell interrupt pending. In this case, the H_CEDE should return immediately, but in fact it puts the VCPU to sleep until some other interrupt becomes pending or a prod is received (via another VCPU doing H_PROD). This fixes it by checking the DPDES (Directed Privileged Doorbell Exception Status) bit for the thread along with the other interrupt pending bits. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> --- arch/powerpc/kvm/book3s_hv.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-)