1 files changed, 56 insertions, 8 deletions

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 783a3e6a0b10..7a97bcb086bf 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -830,11 +830,8 @@ static struct irq_domain *__msi_create_irq_domain(struct fwnode_handle *fwnode,
 	domain = irq_domain_create_hierarchy(parent, flags | IRQ_DOMAIN_FLAG_MSI, 0,
 					     fwnode, &msi_domain_ops, info);
 
-	if (domain) {
-		if (!domain->name && info->chip)
-			domain->name = info->chip->name;
+	if (domain)
 		irq_domain_update_bus_token(domain, info->bus_token);
-	}
 
 	return domain;
 }
@@ -1084,10 +1081,13 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 	struct xarray *xa;
 	int ret, virq;
 
-	if (!msi_ctrl_valid(dev, &ctrl))
-		return -EINVAL;
-
 	msi_lock_descs(dev);
+
+	if (!msi_ctrl_valid(dev, &ctrl)) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
 	ret = msi_domain_add_simple_msi_descs(dev, &ctrl);
 	if (ret)
 		goto unlock;
@@ -1109,14 +1109,35 @@ int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 	return 0;
 
 fail:
-	for (--virq; virq >= virq_base; virq--)
+	for (--virq; virq >= virq_base; virq--) {
+		msi_domain_depopulate_descs(dev, virq, 1);
 		irq_domain_free_irqs_common(domain, virq, 1);
+	}
 	msi_domain_free_descs(dev, &ctrl);
 unlock:
 	msi_unlock_descs(dev);
 	return ret;
 }
 
+void msi_domain_depopulate_descs(struct device *dev, int virq_base, int nvec)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= MSI_DEFAULT_DOMAIN,
+		.first  = virq_base,
+		.last	= virq_base + nvec - 1,
+	};
+	struct msi_desc *desc;
+	struct xarray *xa;
+	unsigned long idx;
+
+	if (!msi_ctrl_valid(dev, &ctrl))
+		return;
+
+	xa = &dev->msi.data->__domains[ctrl.domid].store;
+	xa_for_each_range(xa, idx, desc, ctrl.first, ctrl.last)
+		desc->irq = 0;
+}
+
 /*
  * Carefully check whether the device can use reservation mode. If
  * reservation mode is enabled then the early activation will assign a
@@ -1627,3 +1648,30 @@ struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
 {
 	return (struct msi_domain_info *)domain->host_data;
 }
+
+/**
+ * msi_device_has_isolated_msi - True if the device has isolated MSI
+ * @dev: The device to check
+ *
+ * Isolated MSI means that HW modeled by an irq_domain on the path from the
+ * initiating device to the CPU will validate that the MSI message specifies an
+ * interrupt number that the device is authorized to trigger. This must block
+ * devices from triggering interrupts they are not authorized to trigger.
+ * Currently authorization means the MSI vector is one assigned to the device.
+ *
+ * This is interesting for securing VFIO use cases where a rouge MSI (eg created
+ * by abusing a normal PCI MemWr DMA) must not allow the VFIO userspace to
+ * impact outside its security domain, eg userspace triggering interrupts on
+ * kernel drivers, a VM triggering interrupts on the hypervisor, or a VM
+ * triggering interrupts on another VM.
+ */
+bool msi_device_has_isolated_msi(struct device *dev)
+{
+	struct irq_domain *domain = dev_get_msi_domain(dev);
+
+	for (; domain; domain = domain->parent)
+		if (domain->flags & IRQ_DOMAIN_FLAG_ISOLATED_MSI)
+			return true;
+	return arch_is_isolated_msi();
+}
+EXPORT_SYMBOL_GPL(msi_device_has_isolated_msi);