[Xen-devel] [PATCH v6 35/36] 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 advertise 24 bits worth of LPIs on the guest side, using the full
32 bits seems to trigger a Linux bug (to be investigated).

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/vgic-v3-its.c       | 72 ++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/vgic-v3.c           |  1 +
 xen/include/asm-arm/gic_v3_its.h |  4 +++
 3 files changed, 77 insertions(+)

diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
index ce90187..439210f 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -42,6 +42,7 @@
  */
 struct virt_its {
     struct domain *d;
+    struct list_head vits_list;
     paddr_t doorbell_address;
     unsigned int devid_bits;
     unsigned int intid_bits;
@@ -74,14 +75,48 @@ struct vits_itte
 
 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 bits as the host, and
+             * allow 24 bits for the interrupt ID.
+             */
+            ret = vgic_v3_its_init_virtual(d, hw_its->addr,
+                                           hw_its->devid_bits, 24);
+            if ( ret )
+            {
+                vgic_v3_its_free_domain(d);
+                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));
 }
 
@@ -1255,6 +1290,43 @@ static const struct mmio_handler_ops 
vgic_its_mmio_handler = {
     .write = vgic_v3_its_mmio_write,
 };
 
+int vgic_v3_its_init_virtual(struct domain *d, paddr_t guest_addr,
+                             unsigned int devid_bits, unsigned int intid_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(uint64_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(uint16_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->intid_bits = intid_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 ITSes to be able to clean them up later. */
+    list_add_tail(&its->vits_list, &d->arch.vgic.vits_list);
+
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 1c1d014..d381ce6 100644
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -1659,6 +1659,7 @@ static int vgic_v3_domain_init(struct domain *d)
 
             first_cpu += size / d->arch.vgic.rdist_stride;
         }
+        d->arch.vgic.nr_regions = vgic_v3_hw.nr_rdist_regions;
     }
     else
     {
diff --git a/xen/include/asm-arm/gic_v3_its.h b/xen/include/asm-arm/gic_v3_its.h
index cd2b527..75ce534 100644
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -156,6 +156,10 @@ int gicv3_its_setup_collection(unsigned int cpu);
 int vgic_v3_its_init_domain(struct domain *d);
 void vgic_v3_its_free_domain(struct domain *d);
 
+/* Create and register a virtual ITS at the given guest address. */
+int vgic_v3_its_init_virtual(struct domain *d, paddr_t guest_addr,
+                            unsigned int devid_bits, unsigned int intid_bits);
+
 /*
  * Map a device on the host by allocating an ITT on the host (ITS).
  * "nr_event" specifies how many events (interrupts) this device will need.
-- 
2.9.0


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