[Xen-devel] [PATCH v10 31/32] ARM: vITS: create and initialize virtual ITSes for Dom0

[Andre Przywara <andre.przywara@xxxxxxx>]

For each hardware ITS create and initialize a virtual ITS for Dom0.
We use the same memory mapped address to keep the doorbell working.
This introduces a function to initialize a virtual ITS.
We maintain a list of virtual ITSes, at the moment for the only
purpose of later being able to free them again.
We configure the virtual ITSes to match the hardware ones, that is we
keep the number of device ID bits and event ID bits the same as the host
ITS.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/vgic-v3-its.c   | 77 ++++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/domain.h |  1 +
 2 files changed, 78 insertions(+)

diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
index 5682a38..7567f15 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -52,6 +52,7 @@
  */
 struct virt_its {
     struct domain *d;
+    struct list_head vits_list;
     paddr_t doorbell_address;
     unsigned int devid_bits;
     unsigned int evid_bits;
@@ -1435,6 +1436,46 @@ static const struct mmio_handler_ops 
vgic_its_mmio_handler = {
     .write = vgic_v3_its_mmio_write,
 };
 
+static int vgic_v3_its_init_virtual(struct domain *d, paddr_t guest_addr,
+                                    unsigned int devid_bits,
+                                    unsigned int evid_bits)
+{
+    struct virt_its *its;
+    uint64_t base_attr;
+
+    its = xzalloc(struct virt_its);
+    if ( !its )
+        return -ENOMEM;
+
+    base_attr  = GIC_BASER_InnerShareable << GITS_BASER_SHAREABILITY_SHIFT;
+    base_attr |= GIC_BASER_CACHE_SameAsInner << 
GITS_BASER_OUTER_CACHEABILITY_SHIFT;
+    base_attr |= GIC_BASER_CACHE_RaWaWb << GITS_BASER_INNER_CACHEABILITY_SHIFT;
+
+    its->cbaser  = base_attr;
+    base_attr |= 0ULL << GITS_BASER_PAGE_SIZE_SHIFT;    /* 4K pages */
+    its->baser_dev = GITS_BASER_TYPE_DEVICE << GITS_BASER_TYPE_SHIFT;
+    its->baser_dev |= (sizeof(dev_table_entry_t) - 1) <<
+                      GITS_BASER_ENTRY_SIZE_SHIFT;
+    its->baser_dev |= base_attr;
+    its->baser_coll  = GITS_BASER_TYPE_COLLECTION << GITS_BASER_TYPE_SHIFT;
+    its->baser_coll |= (sizeof(coll_table_entry_t) - 1) <<
+                       GITS_BASER_ENTRY_SIZE_SHIFT;
+    its->baser_coll |= base_attr;
+    its->d = d;
+    its->doorbell_address = guest_addr + ITS_DOORBELL_OFFSET;
+    its->devid_bits = devid_bits;
+    its->evid_bits = evid_bits;
+    spin_lock_init(&its->vcmd_lock);
+    spin_lock_init(&its->its_lock);
+
+    register_mmio_handler(d, &vgic_its_mmio_handler, guest_addr, SZ_64K, its);
+
+    /* Register the virtual ITS to be able to clean it up later. */
+    list_add_tail(&its->vits_list, &d->arch.vgic.vits_list);
+
+    return 0;
+}
+
 unsigned int vgic_v3_its_count(const struct domain *d)
 {
     struct host_its *hw_its;
@@ -1450,16 +1491,52 @@ unsigned int vgic_v3_its_count(const struct domain *d)
     return ret;
 }
 
+/*
+ * For a hardware domain, this will iterate over the host ITSes
+ * and map one virtual ITS per host ITS at the same address.
+ */
 int vgic_v3_its_init_domain(struct domain *d)
 {
+    int ret;
+
+    INIT_LIST_HEAD(&d->arch.vgic.vits_list);
     spin_lock_init(&d->arch.vgic.its_devices_lock);
     d->arch.vgic.its_devices = RB_ROOT;
 
+    if ( is_hardware_domain(d) )
+    {
+        struct host_its *hw_its;
+
+        list_for_each_entry(hw_its, &host_its_list, entry)
+        {
+            /*
+             * For each host ITS create a virtual ITS using the same
+             * base and thus doorbell address.
+             * Use the same number of device ID and event ID bits as the host.
+             */
+            ret = vgic_v3_its_init_virtual(d, hw_its->addr,
+                                           hw_its->devid_bits,
+                                           hw_its->evid_bits);
+            if ( ret )
+                return ret;
+            else
+                d->arch.vgic.has_its = true;
+        }
+    }
+
     return 0;
 }
 
 void vgic_v3_its_free_domain(struct domain *d)
 {
+    struct virt_its *pos, *temp;
+
+    list_for_each_entry_safe( pos, temp, &d->arch.vgic.vits_list, vits_list )
+    {
+        list_del(&pos->vits_list);
+        xfree(pos);
+    }
+
     ASSERT(RB_EMPTY_ROOT(&d->arch.vgic.its_devices));
 }
 
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index b33f54a..8dfc1d1 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -115,6 +115,7 @@ struct arch_domain
         spinlock_t its_devices_lock;        /* Protects the its_devices tree */
         struct radix_tree_root pend_lpi_tree; /* Stores struct pending_irq's */
         rwlock_t pend_lpi_tree_lock;        /* Protects the pend_lpi_tree */
+        struct list_head vits_list;         /* List of virtual ITSes */
         unsigned int intid_bits;
         /*
          * TODO: if there are more bool's being added below, consider
-- 
2.9.0


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