From: ddugger@redhat.com <ddugger@redhat.com>
Date: Mon, 23 Mar 2009 10:23:31 -0600
Subject: [xen] MSI support interface
Message-id: 200903231623.n2NGNVDX022139@sobek.n0ano.com
O-Subject: [RHEL5.4 PATCH 18/21 V2] xen: MSI support interface
Bugzilla: 484227
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>

Add msi specific MAP_PIRQ_TYPE_MSI for map_pirq hypercall so that dom0 can
map MSI as pirq for itself or the guests.

Upstream status: Accepted (CS 17533, 17535)

Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Gerd Hoffman <kraxel@redhat.com>
Signed-off-by: Don Dugger <donald.d.dugger@intel.com>

diff --git a/arch/x86/irq.c b/arch/x86/irq.c
index 3744c0a..afdcf86 100644
--- a/arch/x86/irq.c
+++ b/arch/x86/irq.c
@@ -15,6 +15,7 @@
 #include <xen/keyhandler.h>
 #include <xen/compat.h>
 #include <xen/iocap.h>
+#include <asm/msi.h>
 #include <asm/current.h>
 #include <public/physdev.h>
 
@@ -433,6 +434,13 @@ int pirq_acktype(struct domain *d, int irq)
         return ACKTYPE_NONE;
 
     /*
+     * MSIs are treated as edge-triggered interrupts, except
+     * when there is no proper way to mask them.
+     */
+    if ( desc->handler == &pci_msi_type )
+        return msi_maskable_irq(desc->msi_desc) ? ACKTYPE_NONE : ACKTYPE_EOI;
+
+    /*
      * Level-triggered IO-APIC interrupts need to be acknowledged on the CPU
      * on which they were received. This is because we tickle the LAPIC to EOI.
      */
@@ -760,6 +768,8 @@ int map_domain_pirq(
     int old_vector, old_pirq;
     irq_desc_t *desc;
     unsigned long flags;
+    struct msi_desc *msi_desc;
+    struct pci_dev *pdev = NULL;
 
     ASSERT(spin_is_locked(&pcidevs_lock));
     ASSERT(spin_is_locked(&d->event_lock));
@@ -795,7 +805,26 @@ int map_domain_pirq(
 
     desc = &irq_desc[vector];
 
-    if ( type == MAP_PIRQ_TYPE_GSI )
+    if ( type == MAP_PIRQ_TYPE_MSI )
+    {
+        struct msi_info *msi = (struct msi_info *)data;
+
+        pdev = pci_get_pdev(msi->bus, msi->devfn);
+        ret = pci_enable_msi(msi, &msi_desc);
+        if ( ret )
+            goto done;
+
+        spin_lock_irqsave(&desc->lock, flags);
+
+        if ( desc->handler != &no_irq_type )
+            dprintk(XENLOG_G_ERR, "dom%d: vector %d in use\n",
+              d->domain_id, vector);
+        desc->handler = &pci_msi_type;
+        d->arch.pirq_vector[pirq] = vector;
+        d->arch.vector_pirq[vector] = pirq;
+        setup_msi_irq(pdev, msi_desc);
+        spin_unlock_irqrestore(&desc->lock, flags);
+    } else
     {
         spin_lock_irqsave(&desc->lock, flags);
         d->arch.pirq_vector[pirq] = vector;
@@ -803,6 +832,7 @@ int map_domain_pirq(
         spin_unlock_irqrestore(&desc->lock, flags);
     }
 
+ done:
     return ret;
 }
 
@@ -813,6 +843,7 @@ int unmap_domain_pirq(struct domain *d, int pirq)
     irq_desc_t *desc;
     int vector, ret = 0;
     bool_t forced_unbind;
+    struct msi_desc *msi_desc = NULL;
 
     if ( (pirq < 0) || (pirq >= NR_IRQS) )
         return -EINVAL;
@@ -839,10 +870,19 @@ int unmap_domain_pirq(struct domain *d, int pirq)
 
     desc = &irq_desc[vector];
 
+    if ( (msi_desc = desc->msi_desc) != NULL )
+        pci_disable_msi(msi_desc);
+
     spin_lock_irqsave(&desc->lock, flags);
 
     BUG_ON(vector != d->arch.pirq_vector[pirq]);
 
+    if ( msi_desc )
+        teardown_msi_vector(vector);
+
+    if ( desc->handler == &pci_msi_type )
+        desc->handler = &no_irq_type;
+
     if ( !forced_unbind )
     {
         d->arch.pirq_vector[pirq] = 0;
@@ -855,6 +895,11 @@ int unmap_domain_pirq(struct domain *d, int pirq)
     }
 
     spin_unlock_irqrestore(&desc->lock, flags);
+    if (msi_desc)
+    {
+        msi_free_vector(msi_desc);
+        free_irq_vector(vector);
+    }
 
     ret = irq_deny_access(d, pirq);
     if ( ret )
diff --git a/arch/x86/physdev.c b/arch/x86/physdev.c
index a62cfdf..88cc9dd 100644
--- a/arch/x86/physdev.c
+++ b/arch/x86/physdev.c
@@ -8,6 +8,7 @@
 #include <xen/guest_access.h>
 #include <xen/iocap.h>
 #include <asm/current.h>
+#include <asm/msi.h>
 #include <asm/hypercall.h>
 #include <public/xen.h>
 #include <public/physdev.h>
@@ -28,6 +29,7 @@ static int physdev_map_pirq(struct physdev_map_pirq *map)
 {
     struct domain *d;
     int vector, pirq, ret = 0;
+    struct msi_info _msi;
     void *map_data = NULL;
 
     if ( !IS_PRIV(current->domain) )
@@ -68,6 +70,27 @@ static int physdev_map_pirq(struct physdev_map_pirq *map)
             }
             break;
 
+        case MAP_PIRQ_TYPE_MSI:
+            vector = map->index;
+            if ( vector == -1 )
+                vector = assign_irq_vector(AUTO_ASSIGN);
+
+            if ( vector < 0 || vector >= NR_VECTORS )
+            {
+                dprintk(XENLOG_G_ERR, "dom%d: map irq with wrong vector %d\n",
+                        d->domain_id, vector);
+                ret = -EINVAL;
+                goto free_domain;
+            }
+
+            _msi.bus = map->bus;
+            _msi.devfn = map->devfn;
+            _msi.entry_nr = map->entry_nr;
+            _msi.table_base = map->table_base;
+            _msi.vector = vector;
+            map_data = &_msi;
+            break;
+
         default:
             dprintk(XENLOG_G_ERR, "dom%d: wrong map_pirq type %x\n",
                     d->domain_id, map->type);
@@ -124,6 +147,8 @@ static int physdev_map_pirq(struct physdev_map_pirq *map)
 done:
     spin_unlock(&d->event_lock);
     spin_unlock(&pcidevs_lock);
+    if ( (ret != 0) && (map->type == MAP_PIRQ_TYPE_MSI) && (map->index == -1) )
+        free_irq_vector(vector);
 free_domain:
     rcu_unlock_domain(d);
     return ret;
diff --git a/include/public/physdev.h b/include/public/physdev.h
index 2428540..a710907 100644
--- a/include/public/physdev.h
+++ b/include/public/physdev.h
@@ -118,7 +118,7 @@ struct physdev_irq {
 typedef struct physdev_irq physdev_irq_t;
 DEFINE_XEN_GUEST_HANDLE(physdev_irq_t);
  
-//#define MAP_PIRQ_TYPE_MSI               0x0
+#define MAP_PIRQ_TYPE_MSI               0x0
 #define MAP_PIRQ_TYPE_GSI               0x1
 #define MAP_PIRQ_TYPE_UNKNOWN           0x2