xen/irq: Check if the PCI device is owned by a domain different than DOMID_SELF.

We check if there is a domain owner for the PCI device. In case of failure
(meaning no domain has registered for this device) we make DOMID_SELF the owner.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: deal with rebasing on v2.6.37-1]
[v3: deal with rebasing on stable/irq.cleanup]
[v4: deal with rebasing on stable/irq.ween_of_nr_irqs]
[v5: deal with rebasing on v2.6.39-rc3]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>

3 files changed, 26 insertions, 10 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 6075f2d65335..393981feb12f 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -108,7 +108,8 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                 }
                 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 0,
                                                (type == PCI_CAP_ID_MSIX) ?
-                                               "msi-x" : "msi");
+                                               "msi-x" : "msi",
+                                               DOMID_SELF);
                 if (irq < 0)
                         goto error;
                 dev_dbg(&dev->dev,
@@ -148,7 +149,8 @@ static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
                                                (type == PCI_CAP_ID_MSIX) ?
                                                "pcifront-msi-x" :
-                                               "pcifront-msi");
+                                               "pcifront-msi",
+                                                DOMID_SELF);
                 if (irq < 0)
                         goto free;
                 i++;
@@ -190,9 +192,16 @@ 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.domid = domid;
                 map_irq.type = MAP_PIRQ_TYPE_MSI;
                 map_irq.index = -1;
                 map_irq.pirq = -1;
@@ -215,14 +224,16 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 
                 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
                 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");
+                                               "msi-x" : "msi",
+                                                domid);
                 if (ret < 0)
                         goto out;
         }
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 42d6c930cc87..ac0e22826357 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -101,6 +101,7 @@ struct irq_info
                         unsigned short gsi;
                         unsigned char vector;
                         unsigned char flags;
+                        uint16_t domid;
                 } pirq;
         } u;
 };
@@ -184,6 +185,7 @@ static void xen_irq_info_pirq_init(unsigned irq,
                                    unsigned short pirq,
                                    unsigned short gsi,
                                    unsigned short vector,
+                                   uint16_t domid,
                                    unsigned char flags)
 {
         struct irq_info *info = info_for_irq(irq);
@@ -193,6 +195,7 @@ static void xen_irq_info_pirq_init(unsigned irq,
         info->u.pirq.pirq = pirq;
         info->u.pirq.gsi = gsi;
         info->u.pirq.vector = vector;
+        info->u.pirq.domid = domid;
         info->u.pirq.flags = flags;
 }
 
@@ -655,7 +658,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
                 goto out;
         }
 
-        xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector,
+        xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF,
                                shareable ? PIRQ_SHAREABLE : 0);
 
 out:
@@ -680,7 +683,8 @@ int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 }
 
 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
-                             int pirq, int vector, const char *name)
+                             int pirq, int vector, const char *name,
+                             domid_t domid)
 {
         int irq, ret;
 
@@ -693,7 +697,7 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
         irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq,
                                       name);
 
-        xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, 0);
+        xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0);
         ret = irq_set_msi_desc(irq, msidesc);
         if (ret < 0)
                 goto error_irq;
@@ -722,7 +726,7 @@ int xen_destroy_irq(int irq)
 
         if (xen_initial_domain()) {
                 unmap_irq.pirq = info->u.pirq.pirq;
-                unmap_irq.domid = DOMID_SELF;
+                unmap_irq.domid = info->u.pirq.domid;
                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
                 if (rc) {
                         printk(KERN_WARNING "unmap irq failed %d\n", rc);
diff --git a/include/xen/events.h b/include/xen/events.h
index f1b87ad48ac7..9aecc0b5a0e6 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -85,7 +85,8 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc);
 /* Bind an PSI pirq to an irq. */
 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
-                             int pirq, int vector, const char *name);
+                             int pirq, int vector, const char *name,
+                             domid_t domid);
 #endif
 
 /* De-allocates the above mentioned physical interrupt. */