Merge tag 'kvm-ppc-next-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

PPC KVM update for 4.16

- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs
  without requiring the complex thread synchronization that earlier
  CPU versions required.

- A series from Ben Herrenschmidt to improve the handling of
  escalation interrupts with the XIVE interrupt controller.

- Provide for the decrementer register to be copied across on
  migration.

- Various minor cleanups and bugfixes.

1 files changed, 91 insertions, 18 deletions

diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 0d750d274c4e..badfdbb857a2 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -84,12 +84,22 @@ static irqreturn_t xive_esc_irq(int irq, void *data)
 {
 	struct kvm_vcpu *vcpu = data;
 
-	/* We use the existing H_PROD mechanism to wake up the target */
-	vcpu->arch.prodded = 1;
+	vcpu->arch.irq_pending = 1;
 	smp_mb();
 	if (vcpu->arch.ceded)
 		kvmppc_fast_vcpu_kick(vcpu);
 
+	/* Since we have the no-EOI flag, the interrupt is effectively
+	 * disabled now. Clearing xive_esc_on means we won't bother
+	 * doing so on the next entry.
+	 *
+	 * This also allows the entry code to know that if a PQ combination
+	 * of 10 is observed while xive_esc_on is true, it means the queue
+	 * contains an unprocessed escalation interrupt. We don't make use of
+	 * that knowledge today but might (see comment in book3s_hv_rmhandler.S)
+	 */
+	vcpu->arch.xive_esc_on = false;
+
 	return IRQ_HANDLED;
 }
 
@@ -112,19 +122,21 @@ static int xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio)
 		return -EIO;
 	}
 
-	/*
-	 * Future improvement: start with them disabled
-	 * and handle DD2 and later scheme of merged escalation
-	 * interrupts
-	 */
-	name = kasprintf(GFP_KERNEL, "kvm-%d-%d-%d",
-			 vcpu->kvm->arch.lpid, xc->server_num, prio);
+	if (xc->xive->single_escalation)
+		name = kasprintf(GFP_KERNEL, "kvm-%d-%d",
+				 vcpu->kvm->arch.lpid, xc->server_num);
+	else
+		name = kasprintf(GFP_KERNEL, "kvm-%d-%d-%d",
+				 vcpu->kvm->arch.lpid, xc->server_num, prio);
 	if (!name) {
 		pr_err("Failed to allocate escalation irq name for queue %d of VCPU %d\n",
 		       prio, xc->server_num);
 		rc = -ENOMEM;
 		goto error;
 	}
+
+	pr_devel("Escalation %s irq %d (prio %d)\n", name, xc->esc_virq[prio], prio);
+
 	rc = request_irq(xc->esc_virq[prio], xive_esc_irq,
 			 IRQF_NO_THREAD, name, vcpu);
 	if (rc) {
@@ -133,6 +145,25 @@ static int xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio)
 		goto error;
 	}
 	xc->esc_virq_names[prio] = name;
+
+	/* In single escalation mode, we grab the ESB MMIO of the
+	 * interrupt and mask it. Also populate the VCPU v/raddr
+	 * of the ESB page for use by asm entry/exit code. Finally
+	 * set the XIVE_IRQ_NO_EOI flag which will prevent the
+	 * core code from performing an EOI on the escalation
+	 * interrupt, thus leaving it effectively masked after
+	 * it fires once.
+	 */
+	if (xc->xive->single_escalation) {
+		struct irq_data *d = irq_get_irq_data(xc->esc_virq[prio]);
+		struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+		xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_01);
+		vcpu->arch.xive_esc_raddr = xd->eoi_page;
+		vcpu->arch.xive_esc_vaddr = (__force u64)xd->eoi_mmio;
+		xd->flags |= XIVE_IRQ_NO_EOI;
+	}
+
 	return 0;
 error:
 	irq_dispose_mapping(xc->esc_virq[prio]);
@@ -191,12 +222,12 @@ static int xive_check_provisioning(struct kvm *kvm, u8 prio)
 
 	pr_devel("Provisioning prio... %d\n", prio);
 
-	/* Provision each VCPU and enable escalations */
+	/* Provision each VCPU and enable escalations if needed */
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		if (!vcpu->arch.xive_vcpu)
 			continue;
 		rc = xive_provision_queue(vcpu, prio);
-		if (rc == 0)
+		if (rc == 0 && !xive->single_escalation)
 			xive_attach_escalation(vcpu, prio);
 		if (rc)
 			return rc;
@@ -1082,6 +1113,7 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
 	/* Allocate IPI */
 	xc->vp_ipi = xive_native_alloc_irq();
 	if (!xc->vp_ipi) {
+		pr_err("Failed to allocate xive irq for VCPU IPI\n");
 		r = -EIO;
 		goto bail;
 	}
@@ -1092,18 +1124,33 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
 		goto bail;
 
 	/*
+	 * Enable the VP first as the single escalation mode will
+	 * affect escalation interrupts numbering
+	 */
+	r = xive_native_enable_vp(xc->vp_id, xive->single_escalation);
+	if (r) {
+		pr_err("Failed to enable VP in OPAL, err %d\n", r);
+		goto bail;
+	}
+
+	/*
 	 * Initialize queues. Initially we set them all for no queueing
 	 * and we enable escalation for queue 0 only which we'll use for
 	 * our mfrr change notifications. If the VCPU is hot-plugged, we
-	 * do handle provisioning however.
+	 * do handle provisioning however based on the existing "map"
+	 * of enabled queues.
 	 */
 	for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
 		struct xive_q *q = &xc->queues[i];
 
+		/* Single escalation, no queue 7 */
+		if (i == 7 && xive->single_escalation)
+			break;
+
 		/* Is queue already enabled ? Provision it */
 		if (xive->qmap & (1 << i)) {
 			r = xive_provision_queue(vcpu, i);
-			if (r == 0)
+			if (r == 0 && !xive->single_escalation)
 				xive_attach_escalation(vcpu, i);
 			if (r)
 				goto bail;
@@ -1123,11 +1170,6 @@ int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
 	if (r)
 		goto bail;
 
-	/* Enable the VP */
-	r = xive_native_enable_vp(xc->vp_id);
-	if (r)
-		goto bail;
-
 	/* Route the IPI */
 	r = xive_native_configure_irq(xc->vp_ipi, xc->vp_id, 0, XICS_IPI);
 	if (!r)
@@ -1474,6 +1516,7 @@ static int xive_set_source(struct kvmppc_xive *xive, long irq, u64 addr)
 
 	pr_devel("  val=0x016%llx (server=0x%x, guest_prio=%d)\n",
 		 val, server, guest_prio);
+
 	/*
 	 * If the source doesn't already have an IPI, allocate
 	 * one and get the corresponding data
@@ -1762,6 +1805,8 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
 	if (xive->vp_base == XIVE_INVALID_VP)
 		ret = -ENOMEM;
 
+	xive->single_escalation = xive_native_has_single_escalation();
+
 	if (ret) {
 		kfree(xive);
 		return ret;
@@ -1795,6 +1840,7 @@ static int xive_debug_show(struct seq_file *m, void *private)
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
+		unsigned int i;
 
 		if (!xc)
 			continue;
@@ -1804,6 +1850,33 @@ static int xive_debug_show(struct seq_file *m, void *private)
 			   xc->server_num, xc->cppr, xc->hw_cppr,
 			   xc->mfrr, xc->pending,
 			   xc->stat_rm_h_xirr, xc->stat_vm_h_xirr);
+		for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
+			struct xive_q *q = &xc->queues[i];
+			u32 i0, i1, idx;
+
+			if (!q->qpage && !xc->esc_virq[i])
+				continue;
+
+			seq_printf(m, " [q%d]: ", i);
+
+			if (q->qpage) {
+				idx = q->idx;
+				i0 = be32_to_cpup(q->qpage + idx);
+				idx = (idx + 1) & q->msk;
+				i1 = be32_to_cpup(q->qpage + idx);
+				seq_printf(m, "T=%d %08x %08x... \n", q->toggle, i0, i1);
+			}
+			if (xc->esc_virq[i]) {
+				struct irq_data *d = irq_get_irq_data(xc->esc_virq[i]);
+				struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+				u64 pq = xive_vm_esb_load(xd, XIVE_ESB_GET);
+				seq_printf(m, "E:%c%c I(%d:%llx:%llx)",
+					   (pq & XIVE_ESB_VAL_P) ? 'P' : 'p',
+					   (pq & XIVE_ESB_VAL_Q) ? 'Q' : 'q',
+					   xc->esc_virq[i], pq, xd->eoi_page);
+				seq_printf(m, "\n");
+			}
+		}
 
 		t_rm_h_xirr += xc->stat_rm_h_xirr;
 		t_rm_h_ipoll += xc->stat_rm_h_ipoll;