1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/hv/mshv_irq.c b/drivers/hv/mshv_irq.c
new file mode 100644
index 000000000000..d0fb9ef734f4
--- /dev/null
+++ b/drivers/hv/mshv_irq.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, Microsoft Corporation.
+ *
+ * Authors: Microsoft Linux virtualization team
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/mshyperv.h>
+
+#include "mshv_eventfd.h"
+#include "mshv.h"
+#include "mshv_root.h"
+
+/* called from the ioctl code, user wants to update the guest irq table */
+int mshv_update_routing_table(struct mshv_partition *partition,
+			      const struct mshv_user_irq_entry *ue,
+			      unsigned int numents)
+{
+	struct mshv_girq_routing_table *new = NULL, *old;
+	u32 i, nr_rt_entries = 0;
+	int r = 0;
+
+	if (numents == 0)
+		goto swap_routes;
+
+	for (i = 0; i < numents; i++) {
+		if (ue[i].gsi >= MSHV_MAX_GUEST_IRQS)
+			return -EINVAL;
+
+		if (ue[i].address_hi)
+			return -EINVAL;
+
+		nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
+	}
+	nr_rt_entries += 1;
+
+	new = kzalloc(struct_size(new, mshv_girq_info_tbl, nr_rt_entries),
+		      GFP_KERNEL_ACCOUNT);
+	if (!new)
+		return -ENOMEM;
+
+	new->num_rt_entries = nr_rt_entries;
+	for (i = 0; i < numents; i++) {
+		struct mshv_guest_irq_ent *girq;
+
+		girq = &new->mshv_girq_info_tbl[ue[i].gsi];
+
+		/*
+		 * Allow only one to one mapping between GSI and MSI routing.
+		 */
+		if (girq->guest_irq_num != 0) {
+			r = -EINVAL;
+			goto out;
+		}
+
+		girq->guest_irq_num = ue[i].gsi;
+		girq->girq_addr_lo = ue[i].address_lo;
+		girq->girq_addr_hi = ue[i].address_hi;
+		girq->girq_irq_data = ue[i].data;
+		girq->girq_entry_valid = true;
+	}
+
+swap_routes:
+	mutex_lock(&partition->pt_irq_lock);
+	old = rcu_dereference_protected(partition->pt_girq_tbl, 1);
+	rcu_assign_pointer(partition->pt_girq_tbl, new);
+	mshv_irqfd_routing_update(partition);
+	mutex_unlock(&partition->pt_irq_lock);
+
+	synchronize_srcu_expedited(&partition->pt_irq_srcu);
+	new = old;
+
+out:
+	kfree(new);
+
+	return r;
+}
+
+/* vm is going away, kfree the irq routing table */
+void mshv_free_routing_table(struct mshv_partition *partition)
+{
+	struct mshv_girq_routing_table *rt =
+				   rcu_access_pointer(partition->pt_girq_tbl);
+
+	kfree(rt);
+}
+
+struct mshv_guest_irq_ent
+mshv_ret_girq_entry(struct mshv_partition *partition, u32 irqnum)
+{
+	struct mshv_guest_irq_ent entry = { 0 };
+	struct mshv_girq_routing_table *girq_tbl;
+
+	girq_tbl = srcu_dereference_check(partition->pt_girq_tbl,
+					  &partition->pt_irq_srcu,
+					  lockdep_is_held(&partition->pt_irq_lock));
+	if (!girq_tbl || irqnum >= girq_tbl->num_rt_entries) {
+		/*
+		 * Premature register_irqfd, setting valid_entry = 0
+		 * would ignore this entry anyway
+		 */
+		entry.guest_irq_num = irqnum;
+		return entry;
+	}
+
+	return girq_tbl->mshv_girq_info_tbl[irqnum];
+}
+
+void mshv_copy_girq_info(struct mshv_guest_irq_ent *ent,
+			 struct mshv_lapic_irq *lirq)
+{
+	memset(lirq, 0, sizeof(*lirq));
+	if (!ent || !ent->girq_entry_valid)
+		return;
+
+	lirq->lapic_vector = ent->girq_irq_data & 0xFF;
+	lirq->lapic_apic_id = (ent->girq_addr_lo >> 12) & 0xFF;
+	lirq->lapic_control.interrupt_type = (ent->girq_irq_data & 0x700) >> 8;
+	lirq->lapic_control.level_triggered = (ent->girq_irq_data >> 15) & 0x1;
+	lirq->lapic_control.logical_dest_mode = (ent->girq_addr_lo >> 2) & 0x1;
+}