1 files changed, 32 insertions, 1 deletions

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 955267bbc2be..d0f0389920c1 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1000,7 +1000,7 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid,
 fail:
 	msi_unlock_descs(dev);
 free_fwnode:
-	kfree(fwnode);
+	irq_domain_free_fwnode(fwnode);
 free_bundle:
 	kfree(bundle);
 	return false;
@@ -1013,6 +1013,7 @@ free_bundle:
  */
 void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
 {
+	struct fwnode_handle *fwnode = NULL;
 	struct msi_domain_info *info;
 	struct irq_domain *domain;
 
@@ -1025,7 +1026,10 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
 
 	dev->msi.data->__domains[domid].domain = NULL;
 	info = domain->host_data;
+	if (irq_domain_is_msi_device(domain))
+		fwnode = domain->fwnode;
 	irq_domain_remove(domain);
+	irq_domain_free_fwnode(fwnode);
 	kfree(container_of(info, struct msi_domain_template, info));
 
 unlock:
@@ -1623,3 +1627,30 @@ 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);