[Xen-devel] [RFC PATCH 16/24] ARM: vITS: handle MAPD command

[Andre Przywara <andre.przywara@xxxxxxx>]

The MAPD command maps a device by associating a memory region for
storing ITTEs with a certain device ID.
We just store the given guest physical address in the device table.
We don't map the device tables permanently, as their alignment
requirement is only 256 Bytes, thus making mapping of several tables
complicated. We map the device tables on demand when we need them later.

Also we propagate the MAPD request to the hardware ITS, as the device ID
is only meaningful there.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/vgic-its.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/xen/arch/arm/vgic-its.c b/xen/arch/arm/vgic-its.c
index caad320..83d47e1 100644
--- a/xen/arch/arm/vgic-its.c
+++ b/xen/arch/arm/vgic-its.c
@@ -250,6 +250,34 @@ static int its_handle_mapc(struct virt_its *its, uint64_t 
*cmdptr)
     return ret;
 }
 
+static int its_handle_mapd(struct virt_its *its, uint64_t *cmdptr)
+{
+    uint32_t devid = its_cmd_get_deviceid(cmdptr);
+    int size = its_cmd_get_size(cmdptr);
+    bool valid = its_cmd_get_validbit(cmdptr);
+    paddr_t itt_addr = its_cmd_mask_field(cmdptr, 2, 0, 52) & GENMASK(51, 8);
+
+    if ( !its->dev_table )
+        return -1;
+
+    spin_lock(&its->its_lock);
+    if ( valid )
+        its->dev_table[devid] = DEV_TABLE_ENTRY(itt_addr, size + 1);
+    else
+        its->dev_table[devid] = 0;
+
+    spin_unlock(&its->its_lock);
+
+    /* DomUs (will later) have their ITTs allocated at domain creation time,
+     * when Dom0 configures the passthrough.
+     */
+    if ( its->hw_its )
+        return gicv3_its_map_device(its->hw_its,
+                                    its->d, devid, size + 1, valid);
+
+    return 0;
+}
+
 #define ITS_CMD_BUFFER_SIZE(baser)      ((((baser) & 0xff) + 1) << 12)
 
 static int vgic_its_handle_cmds(struct domain *d, struct virt_its *its,
@@ -279,6 +307,9 @@ static int vgic_its_handle_cmds(struct domain *d, struct 
virt_its *its,
         case GITS_CMD_MAPC:
             its_handle_mapc(its, cmdptr);
             break;
+        case GITS_CMD_MAPD:
+            its_handle_mapd(its, cmdptr);
+           break;
         case GITS_CMD_SYNC:
             /* We handle ITS commands synchronously, so we ignore SYNC. */
            break;
-- 
2.9.0


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