xen: remap MSIs into pirqs when running as initial domain

Implement xen_create_msi_irq to create an msi and remap it as pirq.
Use xen_create_msi_irq to implement an initial domain specific version
of setup_msi_irqs.

Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 37 insertions, 18 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index dd0b5fdb27b9..b3f4b30222fa 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -135,14 +135,12 @@ static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
         if (!v)
                 return -ENOMEM;
 
-        if (!xen_initial_domain()) {
-                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;
-        }
+        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_allocate_pirq(v[i], 0, /* not sharable */
@@ -172,23 +170,40 @@ error:
 
 static void xen_teardown_msi_irqs(struct pci_dev *dev)
 {
-        /* Only do this when were are in non-privileged mode.*/
-        if (!xen_initial_domain()) {
-                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);
-        }
+        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);
 }
 
 static void xen_teardown_msi_irq(unsigned int irq)
 {
         xen_destroy_irq(irq);
 }
+
+static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+        int irq, ret;
+        struct msi_desc *msidesc;
+
+        list_for_each_entry(msidesc, &dev->msi_list, list) {
+                irq = xen_create_msi_irq(dev, msidesc, type);
+                if (irq < 0)
+                        return -1;
+
+                ret = set_irq_msi(irq, msidesc);
+                if (ret)
+                        goto error;
+        }
+        return 0;
+
+error:
+        xen_destroy_irq(irq);
+        return ret;
+}
 #endif
 
 static int xen_pcifront_enable_irq(struct pci_dev *dev)
@@ -362,6 +377,10 @@ static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
 
 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;
+#endif
         xen_setup_acpi_sci();
         __acpi_register_gsi = acpi_register_gsi_xen;