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>

3 files changed, 101 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;
 
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;
diff --git a/include/xen/events.h b/include/xen/events.h
index 0c58db6ea3f4..8fa27dc7358b 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -72,8 +72,12 @@ void xen_hvm_evtchn_do_upcall(void);
  * usual. */
 int xen_allocate_pirq(unsigned gsi, int shareable, char *name);
 int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name);
+
+#ifdef CONFIG_PCI_MSI
 /* Allocate an irq and a pirq to be used with MSIs. */
 void xen_allocate_pirq_msi(char *name, int *irq, int *pirq);
+int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int type);
+#endif
 
 /* De-allocates the above mentioned physical interrupt. */
 int xen_destroy_irq(int irq);