[Xen-devel] [PATCH v9 17/28] ARM: vITS: handle MAPC command

[Andre Przywara <andre.przywara@xxxxxxx>]

The MAPC command associates a given collection ID with a given
redistributor, thus mapping collections to VCPUs.
We just store the vcpu_id in the collection table for that.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/vgic-v3-its.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
index f9379c9..8f1c217 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -118,6 +118,27 @@ static paddr_t get_baser_phys_addr(uint64_t reg)
  */
 
 /* Must be called with the ITS lock held. */
+static int its_set_collection(struct virt_its *its, uint16_t collid,
+                              coll_table_entry_t vcpu_id)
+{
+    paddr_t addr;
+
+    /* The collection table entry must be able to store a VCPU ID. */
+    BUILD_BUG_ON(BIT(sizeof(coll_table_entry_t) * 8) < MAX_VIRT_CPUS);
+
+    addr = get_baser_phys_addr(its->baser_coll);
+
+    ASSERT(spin_is_locked(&its->its_lock));
+
+    if ( collid >= its->max_collections )
+        return -ENOENT;
+
+    return vgic_access_guest_memory(its->d,
+                                    addr + collid * sizeof(coll_table_entry_t),
+                                    &vcpu_id, sizeof(vcpu_id), true);
+}
+
+/* Must be called with the ITS lock held. */
 static struct vcpu *get_vcpu_from_collection(struct virt_its *its,
                                              uint16_t collid)
 {
@@ -318,6 +339,29 @@ static int its_handle_int(struct virt_its *its, uint64_t 
*cmdptr)
     return 0;
 }
 
+static int its_handle_mapc(struct virt_its *its, uint64_t *cmdptr)
+{
+    uint32_t collid = its_cmd_get_collection(cmdptr);
+    uint64_t rdbase = its_cmd_mask_field(cmdptr, 2, 16, 44);
+
+    if ( collid >= its->max_collections )
+        return -1;
+
+    if ( rdbase >= its->d->max_vcpus )
+        return -1;
+
+    spin_lock(&its->its_lock);
+
+    if ( its_cmd_get_validbit(cmdptr) )
+        its_set_collection(its, collid, rdbase);
+    else
+        its_set_collection(its, collid, UNMAPPED_COLLECTION);
+
+    spin_unlock(&its->its_lock);
+
+    return 0;
+}
+
 #define ITS_CMD_BUFFER_SIZE(baser)      ((((baser) & 0xff) + 1) << 12)
 #define ITS_CMD_OFFSET(reg)             ((reg) & GENMASK(19, 5))
 
@@ -350,6 +394,9 @@ static int vgic_its_handle_cmds(struct domain *d, struct 
virt_its *its)
         case GITS_CMD_INT:
             ret = its_handle_int(its, command);
             break;
+        case GITS_CMD_MAPC:
+            ret = its_handle_mapc(its, command);
+            break;
         case GITS_CMD_SYNC:
             /* We handle ITS commands synchronously, so we ignore SYNC. */
             break;
-- 
2.9.0


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