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, 60 insertions, 0 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index c649ac0aaeef..a7d9555e664d 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -29,6 +29,7 @@
 #include <linux/bootmem.h>
 #include <linux/slab.h>
 #include <linux/irqnr.h>
+#include <linux/pci.h>
 
 #include <asm/desc.h>
 #include <asm/ptrace.h>
@@ -656,6 +657,10 @@ out:
         return irq;
 }
 
+#ifdef CONFIG_PCI_MSI
+#include <linux/msi.h>
+#include "../pci/msi.h"
+
 void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
 {
         spin_lock(&irq_mapping_update_lock);
@@ -678,6 +683,61 @@ out:
         spin_unlock(&irq_mapping_update_lock);
 }
 
+int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int type)
+{
+        int irq = -1;
+        struct physdev_map_pirq map_irq;
+        int rc;
+        int pos;
+        u32 table_offset, bir;
+
+        memset(&map_irq, 0, sizeof(map_irq));
+        map_irq.domid = DOMID_SELF;
+        map_irq.type = MAP_PIRQ_TYPE_MSI;
+        map_irq.index = -1;
+        map_irq.pirq = -1;
+        map_irq.bus = dev->bus->number;
+        map_irq.devfn = dev->devfn;
+
+        if (type == PCI_CAP_ID_MSIX) {
+                pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
+
+                pci_read_config_dword(dev, msix_table_offset_reg(pos),
+                                        &table_offset);
+                bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
+
+                map_irq.table_base = pci_resource_start(dev, bir);
+                map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
+        }
+
+        spin_lock(&irq_mapping_update_lock);
+
+        irq = find_unbound_irq();
+
+        if (irq == -1)
+                goto out;
+
+        rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+        if (rc) {
+                printk(KERN_WARNING "xen map irq failed %d\n", rc);
+
+                irq_free_desc(irq);
+
+                irq = -1;
+                goto out;
+        }
+        irq_info[irq] = mk_pirq_info(0, map_irq.pirq, 0, map_irq.index);
+
+        set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
+                        handle_level_irq,
+                        (type == PCI_CAP_ID_MSIX) ? "msi-x":"msi");
+
+out:
+        spin_unlock(&irq_mapping_update_lock);
+        return irq;
+}
+#endif
+
 int xen_destroy_irq(int irq)
 {
         struct irq_desc *desc;