Interrupt remapping to PIRQs in HVM guests

This patch allows HVM guests to remap interrupts and MSIs into pirqs;
once the mapping is in place the guest will receive the interrupt (or
the MSI) as an event.  The interrupt to be remapped can either be an
interrupt of an emulated device or an interrupt of a passthrough
device and we keep track of that.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 128 insertions, 47 deletions

diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index 7f8e71a28b..453b4f3006 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -27,6 +27,59 @@ int
 ioapic_guest_write(
     unsigned long physbase, unsigned int reg, u32 pval);
 
+static int physdev_hvm_map_pirq(
+    struct domain *d, struct physdev_map_pirq *map)
+{
+    int pirq, ret = 0;
+
+    spin_lock(&d->event_lock);
+    switch ( map->type )
+    {
+    case MAP_PIRQ_TYPE_GSI: {
+        struct hvm_irq_dpci *hvm_irq_dpci;
+        struct hvm_girq_dpci_mapping *girq;
+        uint32_t machine_gsi = 0;
+
+        /* find the machine gsi corresponding to the
+         * emulated gsi */
+        hvm_irq_dpci = domain_get_irq_dpci(d);
+        if ( hvm_irq_dpci )
+        {
+            list_for_each_entry ( girq,
+                                  &hvm_irq_dpci->girq[map->index],
+                                  list )
+                machine_gsi = girq->machine_gsi;
+        }
+        /* found one, this mean we are dealing with a pt device */
+        if ( machine_gsi )
+        {
+            map->index = domain_pirq_to_irq(d, machine_gsi);
+            pirq = machine_gsi;
+            ret = (pirq > 0) ? 0 : pirq;
+        }
+        /* we didn't find any, this means we are dealing
+         * with an emulated device */
+        else
+        {
+            pirq = map->pirq;
+            if ( pirq < 0 )
+                pirq = get_free_pirq(d, map->type, map->index);
+            ret = map_domain_emuirq_pirq(d, pirq, map->index);
+        }
+        map->pirq = pirq;
+        break;
+    }
+
+    default:
+        ret = -EINVAL;
+        dprintk(XENLOG_G_WARNING, "map type %d not supported yet\n", map->type);
+        break;
+    }
+
+    spin_unlock(&d->event_lock);
+    return ret;
+}
+
 static int physdev_map_pirq(struct physdev_map_pirq *map)
 {
     struct domain *d;
@@ -43,6 +96,12 @@ static int physdev_map_pirq(struct physdev_map_pirq *map)
     if ( d == NULL )
         return -ESRCH;
 
+    if ( map->domid == DOMID_SELF && is_hvm_domain(d) )
+    {
+        ret = physdev_hvm_map_pirq(d, map);
+        goto free_domain;
+    }
+
     if ( !IS_PRIV_FOR(current->domain, d) )
     {
         ret = -EPERM;
@@ -52,55 +111,55 @@ static int physdev_map_pirq(struct physdev_map_pirq *map)
     /* Verify or get irq. */
     switch ( map->type )
     {
-        case MAP_PIRQ_TYPE_GSI:
-            if ( map->index < 0 || map->index >= nr_irqs_gsi )
-            {
-                dprintk(XENLOG_G_ERR, "dom%d: map invalid irq %d\n",
-                        d->domain_id, map->index);
-                ret = -EINVAL;
-                goto free_domain;
-            }
-
-            irq = domain_pirq_to_irq(current->domain, map->index);
-            if ( !irq )
-            {
-                if ( IS_PRIV(current->domain) )
-                    irq = map->index;
-                else {
-                    dprintk(XENLOG_G_ERR, "dom%d: map pirq with incorrect irq!\n",
-                            d->domain_id);
-                    ret = -EINVAL;
-                    goto free_domain;
-                }
-            }
-            break;
-
-        case MAP_PIRQ_TYPE_MSI:
-            irq = map->index;
-            if ( irq == -1 )
-                irq = create_irq();
+    case MAP_PIRQ_TYPE_GSI:
+        if ( map->index < 0 || map->index >= nr_irqs_gsi )
+        {
+            dprintk(XENLOG_G_ERR, "dom%d: map invalid irq %d\n",
+                    d->domain_id, map->index);
+            ret = -EINVAL;
+            goto free_domain;
+        }
 
-            if ( irq < 0 || irq >= nr_irqs )
-            {
-                dprintk(XENLOG_G_ERR, "dom%d: can't create irq for msi!\n",
+        irq = domain_pirq_to_irq(current->domain, map->index);
+        if ( !irq )
+        {
+            if ( IS_PRIV(current->domain) )
+                irq = map->index;
+            else {
+                dprintk(XENLOG_G_ERR, "dom%d: map pirq with incorrect irq!\n",
                         d->domain_id);
                 ret = -EINVAL;
                 goto free_domain;
             }
+        }
+        break;
 
-            _msi.bus = map->bus;
-            _msi.devfn = map->devfn;
-            _msi.entry_nr = map->entry_nr;
-            _msi.table_base = map->table_base;
-            _msi.irq = irq;
-            map_data = &_msi;
-            break;
+    case MAP_PIRQ_TYPE_MSI:
+        irq = map->index;
+        if ( irq == -1 )
+            irq = create_irq();
 
-        default:
-            dprintk(XENLOG_G_ERR, "dom%d: wrong map_pirq type %x\n",
-                    d->domain_id, map->type);
+        if ( irq < 0 || irq >= nr_irqs )
+        {
+            dprintk(XENLOG_G_ERR, "dom%d: can't create irq for msi!\n",
+                    d->domain_id);
             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.irq = irq;
+        map_data = &_msi;
+        break;
+
+    default:
+        dprintk(XENLOG_G_ERR, "dom%d: wrong map_pirq type %x\n",
+                d->domain_id, map->type);
+        ret = -EINVAL;
+        goto free_domain;
     }
 
     spin_lock(&pcidevs_lock);
@@ -148,12 +207,15 @@ static int physdev_map_pirq(struct physdev_map_pirq *map)
     if ( ret == 0 )
         map->pirq = pirq;
 
-done:
+    if ( !ret && is_hvm_domain(d) )
+        map_domain_emuirq_pirq(d, pirq, IRQ_PT);
+
+ done:
     spin_unlock(&d->event_lock);
     spin_unlock(&pcidevs_lock);
     if ( (ret != 0) && (map->type == MAP_PIRQ_TYPE_MSI) && (map->index == -1) )
         destroy_irq(irq);
-free_domain:
+ free_domain:
     rcu_unlock_domain(d);
     return ret;
 }
@@ -169,6 +231,14 @@ static int physdev_unmap_pirq(struct physdev_unmap_pirq *unmap)
     if ( d == NULL )
         return -ESRCH;
 
+    if ( is_hvm_domain(d) )
+    {
+        spin_lock(&d->event_lock);
+        ret = unmap_domain_pirq_emuirq(d, unmap->pirq);
+        spin_unlock(&d->event_lock);
+        goto free_domain;
+    }
+
     ret = -EPERM;
     if ( !IS_PRIV_FOR(current->domain, d) )
         goto free_domain;
@@ -179,7 +249,7 @@ static int physdev_unmap_pirq(struct physdev_unmap_pirq *unmap)
     spin_unlock(&d->event_lock);
     spin_unlock(&pcidevs_lock);
 
-free_domain:
+ free_domain:
     rcu_unlock_domain(d);
     return ret;
 }
@@ -202,7 +272,11 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
             break;
         if ( v->domain->arch.pirq_eoi_map )
             evtchn_unmask(v->domain->pirq_to_evtchn[eoi.irq]);
-        ret = pirq_guest_eoi(v->domain, eoi.irq);
+        if ( !is_hvm_domain(v->domain) ||
+             domain_pirq_to_emuirq(v->domain, eoi.irq) == IRQ_PT )
+            ret = pirq_guest_eoi(v->domain, eoi.irq);
+        else
+            ret = 0;
         break;
     }
 
@@ -257,6 +331,13 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         if ( (irq < 0) || (irq >= v->domain->nr_pirqs) )
             break;
         irq_status_query.flags = 0;
+        if ( is_hvm_domain(v->domain) &&
+             domain_pirq_to_emuirq(v->domain, irq) != IRQ_PT )
+        {
+            ret = copy_to_guest(arg, &irq_status_query, 1) ? -EFAULT : 0;
+            break;
+        }
+
         /*
          * Even edge-triggered or message-based IRQs can need masking from
          * time to time. If teh guest is not dynamically checking for this
@@ -345,9 +426,9 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
             break;
 
         /* Vector is only used by hypervisor, and dom0 shouldn't
-         touch it in its world, return irq_op.irq as the vecotr,
-         and make this hypercall dummy, and also defer the vector 
-         allocation when dom0 tries to programe ioapic entry. */
+           touch it in its world, return irq_op.irq as the vecotr,
+           and make this hypercall dummy, and also defer the vector 
+           allocation when dom0 tries to programe ioapic entry. */
         irq_op.vector = irq_op.irq;
         ret = 0;