1 files changed, 355 insertions, 215 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index e37b407a0ee..905956f1646 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -1,8 +1,13 @@
 /*
- * Xen PCI Frontend Stub - puts some "dummy" functions in to the Linux
- *			   x86 PCI core to support the Xen PCI Frontend
+ * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
+ * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
+ * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
+ * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
+ * 0xcf8 PCI configuration read/write.
  *
  *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ *           Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+ *           Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  */
 #include <linux/module.h>
 #include <linux/init.h>
@@ -19,22 +24,57 @@
 #include <xen/events.h>
 #include <asm/xen/pci.h>
 
+static int xen_pcifront_enable_irq(struct pci_dev *dev)
+{
+	int rc;
+	int share = 1;
+	int pirq;
+	u8 gsi;
+
+	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
+	if (rc < 0) {
+		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
+			 rc);
+		return rc;
+	}
+	/* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
+	pirq = gsi;
+
+	if (gsi < NR_IRQS_LEGACY)
+		share = 0;
+
+	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
+	if (rc < 0) {
+		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
+			 gsi, pirq, rc);
+		return rc;
+	}
+
+	dev->irq = rc;
+	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
+	return 0;
+}
+
 #ifdef CONFIG_ACPI
-static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
-				 int trigger, int polarity)
+static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
+			     bool set_pirq)
 {
-	int rc, irq;
+	int rc, pirq = -1, irq = -1;
 	struct physdev_map_pirq map_irq;
 	int shareable = 0;
 	char *name;
 
-	if (!xen_hvm_domain())
-		return -1;
+	irq = xen_irq_from_gsi(gsi);
+	if (irq > 0)
+		return irq;
+
+	if (set_pirq)
+		pirq = gsi;
 
 	map_irq.domid = DOMID_SELF;
 	map_irq.type = MAP_PIRQ_TYPE_GSI;
 	map_irq.index = gsi;
-	map_irq.pirq = -1;
+	map_irq.pirq = pirq;
 
 	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
 	if (rc) {
@@ -42,7 +82,7 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 		return -1;
 	}
 
-	if (trigger == ACPI_EDGE_SENSITIVE) {
+	if (triggering == ACPI_EDGE_SENSITIVE) {
 		shareable = 0;
 		name = "ioapic-edge";
 	} else {
@@ -50,12 +90,63 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 		name = "ioapic-level";
 	}
 
+	if (gsi_override >= 0)
+		gsi = gsi_override;
+
 	irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
+	if (irq < 0)
+		goto out;
+
+	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
+out:
+	return irq;
+}
+
+static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
+				     int trigger, int polarity)
+{
+	if (!xen_hvm_domain())
+		return -1;
+
+	return xen_register_pirq(gsi, -1 /* no GSI override */, trigger,
+				 false /* no mapping of GSI to PIRQ */);
+}
+
+#ifdef CONFIG_XEN_DOM0
+static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
+{
+	int rc, irq;
+	struct physdev_setup_gsi setup_gsi;
+
+	if (!xen_pv_domain())
+		return -1;
+
+	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
+			gsi, triggering, polarity);
+
+	irq = xen_register_pirq(gsi, gsi_override, triggering, true);
 
-	printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
+	setup_gsi.gsi = gsi;
+	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
+	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+
+	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
+	if (rc == -EEXIST)
+		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
+	else if (rc) {
+		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
+				gsi, rc);
+	}
 
 	return irq;
 }
+
+static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
+				 int trigger, int polarity)
+{
+	return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
+}
+#endif
 #endif
 
 #if defined(CONFIG_PCI_MSI)
@@ -65,6 +156,49 @@ static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 struct xen_pci_frontend_ops *xen_pci_frontend;
 EXPORT_SYMBOL_GPL(xen_pci_frontend);
 
+static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	int irq, ret, i;
+	struct msi_desc *msidesc;
+	int *v;
+
+	if (type == PCI_CAP_ID_MSI && nvec > 1)
+		return 1;
+
+	v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
+	if (!v)
+		return -ENOMEM;
+
+	if (type == PCI_CAP_ID_MSIX)
+		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
+	else
+		ret = xen_pci_frontend_enable_msi(dev, v);
+	if (ret)
+		goto error;
+	i = 0;
+	list_for_each_entry(msidesc, &dev->msi_list, list) {
+		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i],
+					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
+					       (type == PCI_CAP_ID_MSIX) ?
+					       "pcifront-msi-x" :
+					       "pcifront-msi",
+						DOMID_SELF);
+		if (irq < 0) {
+			ret = irq;
+			goto free;
+		}
+		i++;
+	}
+	kfree(v);
+	return 0;
+
+error:
+	dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
+free:
+	kfree(v);
+	return ret;
+}
+
 #define XEN_PIRQ_MSI_DATA  (MSI_DATA_TRIGGER_EDGE | \
 		MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
 
@@ -90,6 +224,9 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 	struct msi_desc *msidesc;
 	struct msi_msg msg;
 
+	if (type == PCI_CAP_ID_MSI && nvec > 1)
+		return 1;
+
 	list_for_each_entry(msidesc, &dev->msi_list, list) {
 		__read_msi_msg(msidesc, &msg);
 		pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) |
@@ -97,8 +234,10 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 		if (msg.data != XEN_PIRQ_MSI_DATA ||
 		    xen_irq_from_pirq(pirq) < 0) {
 			pirq = xen_allocate_pirq_msi(dev, msidesc);
-			if (pirq < 0)
+			if (pirq < 0) {
+				irq = -ENODEV;
 				goto error;
+			}
 			xen_msi_compose_msg(dev, pirq, &msg);
 			__write_msi_msg(msidesc, &msg);
 			dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
@@ -106,9 +245,11 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 			dev_dbg(&dev->dev,
 				"xen: msi already bound to pirq=%d\n", pirq);
 		}
-		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 0,
+		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq,
+					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
 					       (type == PCI_CAP_ID_MSIX) ?
-					       "msi-x" : "msi");
+					       "msi-x" : "msi",
+					       DOMID_SELF);
 		if (irq < 0)
 			goto error;
 		dev_dbg(&dev->dev,
@@ -119,70 +260,12 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 error:
 	dev_err(&dev->dev,
 		"Xen PCI frontend has not registered MSI/MSI-X support!\n");
-	return -ENODEV;
-}
-
-/*
- * For MSI interrupts we have to use drivers/xen/event.s functions to
- * allocate an irq_desc and setup the right */
-
-
-static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
-{
-	int irq, ret, i;
-	struct msi_desc *msidesc;
-	int *v;
-
-	v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
-	if (!v)
-		return -ENOMEM;
-
-	if (type == PCI_CAP_ID_MSIX)
-		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
-	else
-		ret = xen_pci_frontend_enable_msi(dev, v);
-	if (ret)
-		goto error;
-	i = 0;
-	list_for_each_entry(msidesc, &dev->msi_list, list) {
-		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
-					       (type == PCI_CAP_ID_MSIX) ?
-					       "pcifront-msi-x" :
-					       "pcifront-msi");
-		if (irq < 0)
-			goto free;
-		i++;
-	}
-	kfree(v);
-	return 0;
-
-error:
-	dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
-free:
-	kfree(v);
-	return ret;
-}
-
-static void xen_teardown_msi_irqs(struct pci_dev *dev)
-{
-	struct msi_desc *msidesc;
-
-	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
-	if (msidesc->msi_attrib.is_msix)
-		xen_pci_frontend_disable_msix(dev);
-	else
-		xen_pci_frontend_disable_msi(dev);
-
-	/* Free the IRQ's and the msidesc using the generic code. */
-	default_teardown_msi_irqs(dev);
-}
-
-static void xen_teardown_msi_irq(unsigned int irq)
-{
-	xen_destroy_irq(irq);
+	return irq;
 }
 
 #ifdef CONFIG_XEN_DOM0
+static bool __read_mostly pci_seg_supported = true;
+
 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
 	int ret = 0;
@@ -190,39 +273,73 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 
 	list_for_each_entry(msidesc, &dev->msi_list, list) {
 		struct physdev_map_pirq map_irq;
+		domid_t domid;
+
+		domid = ret = xen_find_device_domain_owner(dev);
+		/* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
+		 * hence check ret value for < 0. */
+		if (ret < 0)
+			domid = DOMID_SELF;
 
 		memset(&map_irq, 0, sizeof(map_irq));
-		map_irq.domid = DOMID_SELF;
-		map_irq.type = MAP_PIRQ_TYPE_MSI;
+		map_irq.domid = domid;
+		map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
 		map_irq.index = -1;
 		map_irq.pirq = -1;
-		map_irq.bus = dev->bus->number;
+		map_irq.bus = dev->bus->number |
+			      (pci_domain_nr(dev->bus) << 16);
 		map_irq.devfn = dev->devfn;
 
-		if (type == PCI_CAP_ID_MSIX) {
+		if (type == PCI_CAP_ID_MSI && nvec > 1) {
+			map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI;
+			map_irq.entry_nr = nvec;
+		} else if (type == PCI_CAP_ID_MSIX) {
 			int pos;
 			u32 table_offset, bir;
 
-			pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
-
+			pos = dev->msix_cap;
 			pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
 					      &table_offset);
-			bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
+			bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
 
 			map_irq.table_base = pci_resource_start(dev, bir);
 			map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
 		}
 
-		ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+		ret = -EINVAL;
+		if (pci_seg_supported)
+			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
+						    &map_irq);
+		if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) {
+			/*
+			 * If MAP_PIRQ_TYPE_MULTI_MSI is not available
+			 * there's nothing else we can do in this case.
+			 * Just set ret > 0 so driver can retry with
+			 * single MSI.
+			 */
+			ret = 1;
+			goto out;
+		}
+		if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
+			map_irq.type = MAP_PIRQ_TYPE_MSI;
+			map_irq.index = -1;
+			map_irq.pirq = -1;
+			map_irq.bus = dev->bus->number;
+			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
+						    &map_irq);
+			if (ret != -EINVAL)
+				pci_seg_supported = false;
+		}
 		if (ret) {
-			dev_warn(&dev->dev, "xen map irq failed %d\n", ret);
+			dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
+				 ret, domid);
 			goto out;
 		}
 
-		ret = xen_bind_pirq_msi_to_irq(dev, msidesc,
-					       map_irq.pirq, map_irq.index,
-					       (type == PCI_CAP_ID_MSIX) ?
-					       "msi-x" : "msi");
+		ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq,
+		                               (type == PCI_CAP_ID_MSI) ? nvec : 1,
+		                               (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi",
+		                               domid);
 		if (ret < 0)
 			goto out;
 	}
@@ -230,45 +347,61 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 out:
 	return ret;
 }
-#endif
-#endif
 
-static int xen_pcifront_enable_irq(struct pci_dev *dev)
+static void xen_initdom_restore_msi_irqs(struct pci_dev *dev)
 {
-	int rc;
-	int share = 1;
-	int pirq;
-	u8 gsi;
+	int ret = 0;
 
-	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
-	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
-			 rc);
-		return rc;
+	if (pci_seg_supported) {
+		struct physdev_pci_device restore_ext;
+
+		restore_ext.seg = pci_domain_nr(dev->bus);
+		restore_ext.bus = dev->bus->number;
+		restore_ext.devfn = dev->devfn;
+		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
+					&restore_ext);
+		if (ret == -ENOSYS)
+			pci_seg_supported = false;
+		WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
 	}
+	if (!pci_seg_supported) {
+		struct physdev_restore_msi restore;
 
-	rc = xen_allocate_pirq_gsi(gsi);
-	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI: failed to allocate a PIRQ for GSI%d: %d\n",
-			 gsi, rc);
-		return rc;
+		restore.bus = dev->bus->number;
+		restore.devfn = dev->devfn;
+		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
+		WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
 	}
-	pirq = rc;
+}
+#endif
 
-	if (gsi < NR_IRQS_LEGACY)
-		share = 0;
+static void xen_teardown_msi_irqs(struct pci_dev *dev)
+{
+	struct msi_desc *msidesc;
 
-	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
-	if (rc < 0) {
-		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
-			 gsi, pirq, rc);
-		return rc;
-	}
+	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
+	if (msidesc->msi_attrib.is_msix)
+		xen_pci_frontend_disable_msix(dev);
+	else
+		xen_pci_frontend_disable_msi(dev);
 
-	dev->irq = rc;
-	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
+	/* Free the IRQ's and the msidesc using the generic code. */
+	default_teardown_msi_irqs(dev);
+}
+
+static void xen_teardown_msi_irq(unsigned int irq)
+{
+	xen_destroy_irq(irq);
+}
+static u32 xen_nop_msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
+{
 	return 0;
 }
+static u32 xen_nop_msix_mask_irq(struct msi_desc *desc, u32 flag)
+{
+	return 0;
+}
+#endif
 
 int __init pci_xen_init(void)
 {
@@ -291,13 +424,15 @@ int __init pci_xen_init(void)
 	x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
 	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 	x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
+	x86_msi.msi_mask_irq = xen_nop_msi_mask_irq;
+	x86_msi.msix_mask_irq = xen_nop_msix_mask_irq;
 #endif
 	return 0;
 }
 
 int __init pci_xen_hvm_init(void)
 {
-	if (!xen_feature(XENFEAT_hvm_pirqs))
+	if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
 		return 0;
 
 #ifdef CONFIG_ACPI
@@ -316,82 +451,13 @@ int __init pci_xen_hvm_init(void)
 }
 
 #ifdef CONFIG_XEN_DOM0
-static int xen_register_pirq(u32 gsi, int triggering)
-{
-	int rc, pirq, irq = -1;
-	struct physdev_map_pirq map_irq;
-	int shareable = 0;
-	char *name;
-
-	if (!xen_pv_domain())
-		return -1;
-
-	if (triggering == ACPI_EDGE_SENSITIVE) {
-		shareable = 0;
-		name = "ioapic-edge";
-	} else {
-		shareable = 1;
-		name = "ioapic-level";
-	}
-
-	pirq = xen_allocate_pirq_gsi(gsi);
-	if (pirq < 0)
-		goto out;
-
-	irq = xen_bind_pirq_gsi_to_irq(gsi, pirq, shareable, name);
-	if (irq < 0)
-		goto out;
-
-	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d\n", pirq, irq);
-
-	map_irq.domid = DOMID_SELF;
-	map_irq.type = MAP_PIRQ_TYPE_GSI;
-	map_irq.index = gsi;
-	map_irq.pirq = pirq;
-
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
-	if (rc) {
-		printk(KERN_WARNING "xen map irq failed %d\n", rc);
-		return -1;
-	}
-
-out:
-	return irq;
-}
-
-static int xen_register_gsi(u32 gsi, int triggering, int polarity)
-{
-	int rc, irq;
-	struct physdev_setup_gsi setup_gsi;
-
-	if (!xen_pv_domain())
-		return -1;
-
-	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
-			gsi, triggering, polarity);
-
-	irq = xen_register_pirq(gsi, triggering);
-
-	setup_gsi.gsi = gsi;
-	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
-	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
-
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
-	if (rc == -EEXIST)
-		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
-	else if (rc) {
-		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
-				gsi, rc);
-	}
-
-	return irq;
-}
-
 static __init void xen_setup_acpi_sci(void)
 {
 	int rc;
 	int trigger, polarity;
 	int gsi = acpi_sci_override_gsi;
+	int irq = -1;
+	int gsi_override = -1;
 
 	if (!gsi)
 		return;
@@ -404,60 +470,134 @@ static __init void xen_setup_acpi_sci(void)
 	}
 	trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 	polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
-	
+
 	printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
 			"polarity=%d\n", gsi, trigger, polarity);
 
-	gsi = xen_register_gsi(gsi, trigger, polarity);
+	/* Before we bind the GSI to a Linux IRQ, check whether
+	 * we need to override it with bus_irq (IRQ) value. Usually for
+	 * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so:
+	 *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
+	 * but there are oddballs where the IRQ != GSI:
+	 *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
+	 * which ends up being: gsi_to_irq[9] == 20
+	 * (which is what acpi_gsi_to_irq ends up calling when starting the
+	 * the ACPI interpreter and keels over since IRQ 9 has not been
+	 * setup as we had setup IRQ 20 for it).
+	 */
+	if (acpi_gsi_to_irq(gsi, &irq) == 0) {
+		/* Use the provided value if it's valid. */
+		if (irq >= 0)
+			gsi_override = irq;
+	}
+
+	gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity);
 	printk(KERN_INFO "xen: acpi sci %d\n", gsi);
 
 	return;
 }
 
-static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
-				 int trigger, int polarity)
+int __init pci_xen_initial_domain(void)
 {
-	return xen_register_gsi(gsi, trigger, polarity);
-}
+	int irq;
 
-static int __init pci_xen_initial_domain(void)
-{
 #ifdef CONFIG_PCI_MSI
 	x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
 	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+	x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
+	x86_msi.msi_mask_irq = xen_nop_msi_mask_irq;
+	x86_msi.msix_mask_irq = xen_nop_msix_mask_irq;
 #endif
 	xen_setup_acpi_sci();
 	__acpi_register_gsi = acpi_register_gsi_xen;
+	/* Pre-allocate legacy irqs */
+	for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
+		int trigger, polarity;
 
+		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
+			continue;
+
+		xen_register_pirq(irq, -1 /* no GSI override */,
+			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
+			true /* Map GSI to PIRQ */);
+	}
+	if (0 == nr_ioapics) {
+		for (irq = 0; irq < NR_IRQS_LEGACY; irq++)
+			xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
+	}
 	return 0;
 }
 
-void __init xen_setup_pirqs(void)
-{
-	int pirq, irq;
+struct xen_device_domain_owner {
+	domid_t domain;
+	struct pci_dev *dev;
+	struct list_head list;
+};
 
-	pci_xen_initial_domain();
+static DEFINE_SPINLOCK(dev_domain_list_spinlock);
+static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
 
-	if (0 == nr_ioapics) {
-		for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
-			pirq = xen_allocate_pirq_gsi(irq);
-			if (WARN(pirq < 0,
-				 "Could not allocate PIRQ for legacy interrupt\n"))
-				break;
-			irq = xen_bind_pirq_gsi_to_irq(irq, pirq, 0, "xt-pic");
-		}
-		return;
+static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
+{
+	struct xen_device_domain_owner *owner;
+
+	list_for_each_entry(owner, &dev_domain_list, list) {
+		if (owner->dev == dev)
+			return owner;
 	}
+	return NULL;
+}
 
-	/* Pre-allocate legacy irqs */
-	for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
-		int trigger, polarity;
+int xen_find_device_domain_owner(struct pci_dev *dev)
+{
+	struct xen_device_domain_owner *owner;
+	int domain = -ENODEV;
+
+	spin_lock(&dev_domain_list_spinlock);
+	owner = find_device(dev);
+	if (owner)
+		domain = owner->domain;
+	spin_unlock(&dev_domain_list_spinlock);
+	return domain;
+}
+EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
 
-		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
-			continue;
+int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
+{
+	struct xen_device_domain_owner *owner;
 
-		xen_register_pirq(irq,
-			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE);
+	owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
+	if (!owner)
+		return -ENODEV;
+
+	spin_lock(&dev_domain_list_spinlock);
+	if (find_device(dev)) {
+		spin_unlock(&dev_domain_list_spinlock);
+		kfree(owner);
+		return -EEXIST;
+	}
+	owner->domain = domain;
+	owner->dev = dev;
+	list_add_tail(&owner->list, &dev_domain_list);
+	spin_unlock(&dev_domain_list_spinlock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
+
+int xen_unregister_device_domain_owner(struct pci_dev *dev)
+{
+	struct xen_device_domain_owner *owner;
+
+	spin_lock(&dev_domain_list_spinlock);
+	owner = find_device(dev);
+	if (!owner) {
+		spin_unlock(&dev_domain_list_spinlock);
+		return -ENODEV;
 	}
+	list_del(&owner->list);
+	spin_unlock(&dev_domain_list_spinlock);
+	kfree(owner);
+	return 0;
 }
+EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
 #endif