2 files changed, 25 insertions, 12 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 6084b38bdda1..178da6b9fc33 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1757,8 +1757,7 @@ static int hv_compose_multi_msi_req_get_cpu(void)
 
 	spin_lock_irqsave(&multi_msi_cpu_lock, flags);
 
-	cpu_next = cpumask_next_wrap(cpu_next, cpu_online_mask, nr_cpu_ids,
-				     false);
+	cpu_next = cpumask_next_wrap(cpu_next, cpu_online_mask);
 	cpu = cpu_next;
 
 	spin_unlock_irqrestore(&multi_msi_cpu_lock, flags);
@@ -3976,24 +3975,18 @@ static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg)
 {
 	struct irq_data *irq_data;
 	struct msi_desc *entry;
-	int ret = 0;
 
 	if (!pdev->msi_enabled && !pdev->msix_enabled)
 		return 0;
 
-	msi_lock_descs(&pdev->dev);
+	guard(msi_descs_lock)(&pdev->dev);
 	msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) {
 		irq_data = irq_get_irq_data(entry->irq);
-		if (WARN_ON_ONCE(!irq_data)) {
-			ret = -EINVAL;
-			break;
-		}
-
+		if (WARN_ON_ONCE(!irq_data))
+			return -EINVAL;
 		hv_compose_msi_msg(irq_data, &entry->msg);
 	}
-	msi_unlock_descs(&pdev->dev);
-
-	return ret;
+	return 0;
 }
 
 /*
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 9d9596947350..e619accca49d 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -17,6 +17,8 @@
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 
+#include <xen/xen.h>
+
 #include <asm/irqdomain.h>
 
 #define VMD_CFGBAR	0
@@ -970,6 +972,24 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	struct vmd_dev *vmd;
 	int err;
 
+	if (xen_domain()) {
+		/*
+		 * Xen doesn't have knowledge about devices in the VMD bus
+		 * because the config space of devices behind the VMD bridge is
+		 * not known to Xen, and hence Xen cannot discover or configure
+		 * them in any way.
+		 *
+		 * Bypass of MSI remapping won't work in that case as direct
+		 * write by Linux to the MSI entries won't result in functional
+		 * interrupts, as Xen is the entity that manages the host
+		 * interrupt controller and must configure interrupts.  However
+		 * multiplexing of interrupts by the VMD bridge will work under
+		 * Xen, so force the usage of that mode which must always be
+		 * supported by VMD bridges.
+		 */
+		features &= ~VMD_FEAT_CAN_BYPASS_MSI_REMAP;
+	}
+
 	if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
 		return -ENOMEM;