[Xen-devel] [RFC PATCH 18/24] ARM: vITS: handle MOVI command

[Andre Przywara <andre.przywara@xxxxxxx>]

The MOVI command moves the interrupt affinity from one redistributor
(read: VCPU) to another.
For now migration of "live" LPIs is not yet implemented, but we store
the changed affinity in the host LPI structure and in our virtual ITTE.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/gic-its.c        | 16 +++++++++++++++
 xen/arch/arm/vgic-its.c       | 46 +++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/gic-its.h |  1 +
 3 files changed, 63 insertions(+)

diff --git a/xen/arch/arm/gic-its.c b/xen/arch/arm/gic-its.c
index 6bac422..d1b1cbb 100644
--- a/xen/arch/arm/gic-its.c
+++ b/xen/arch/arm/gic-its.c
@@ -618,6 +618,22 @@ int gicv3_lpi_drop_host_lpi(struct host_its *its,
     return 0;
 }
 
+/* Changes the target VCPU for a given host LPI assigned to a domain. */
+int gicv3_lpi_change_vcpu(struct domain *d, uint32_t host_lpi, int new_vcpu_id)
+{
+    union host_lpi *hlpip, hlpi;
+
+    hlpip = gic_find_host_lpi(host_lpi, d);
+    if ( !hlpip )
+        return -1;
+
+    hlpi.data = hlpip->data;
+    hlpi.vcpu_id = new_vcpu_id;
+    hlpip->data = hlpi.data;
+
+    return 0;
+}
+
 void gicv3_its_dt_init(const struct dt_device_node *node)
 {
     const struct dt_device_node *its = NULL;
diff --git a/xen/arch/arm/vgic-its.c b/xen/arch/arm/vgic-its.c
index 70897dd..c0a60ad 100644
--- a/xen/arch/arm/vgic-its.c
+++ b/xen/arch/arm/vgic-its.c
@@ -327,6 +327,46 @@ out_unlock:
     return ret;
 }
 
+static int its_handle_movi(struct virt_its *its, uint64_t *cmdptr)
+{
+    uint32_t devid = its_cmd_get_deviceid(cmdptr);
+    uint32_t eventid = its_cmd_get_id(cmdptr);
+    int collid = its_cmd_get_collection(cmdptr);
+    struct vits_itte *itte;
+    struct vcpu *vcpu;
+    uint32_t host_lpi = 0;
+
+    if ( collid >= its->max_collections )
+        return -1;
+
+    spin_lock(&its->its_lock);
+
+    vcpu = get_vcpu_from_collection(its, collid);
+    if ( !vcpu )
+        goto out_unlock;
+
+    itte = get_devid_evid(its, devid, eventid);
+    if ( !itte )
+        goto out_unlock;
+
+    itte->collection = collid;
+    host_lpi = itte->hlpi;
+
+    /* TODO: lookup currently-in-guest virtual IRQs and migrate them */
+
+    put_devid_evid(its, itte);
+
+out_unlock:
+    spin_unlock(&its->its_lock);
+
+    if ( !host_lpi )
+        return -1;
+
+    gicv3_lpi_change_vcpu(its->d, host_lpi, vcpu->vcpu_id);
+
+    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,
@@ -363,6 +403,12 @@ static int vgic_its_handle_cmds(struct domain *d, struct 
virt_its *its,
         case GITS_CMD_MAPTI:
             its_handle_mapti(its, cmdptr);
             break;
+        case GITS_CMD_MOVALL:
+            gdprintk(XENLOG_G_INFO, "ITS: ignoring MOVALL command\n");
+            break;
+        case GITS_CMD_MOVI:
+            its_handle_movi(its, cmdptr);
+            break;
         case GITS_CMD_SYNC:
             /* We handle ITS commands synchronously, so we ignore SYNC. */
            break;
diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
index 3b2e5c0..7e1142f 100644
--- a/xen/include/asm-arm/gic-its.h
+++ b/xen/include/asm-arm/gic-its.h
@@ -133,6 +133,7 @@ int gicv3_its_map_device(struct host_its *hw_its, struct 
domain *d,
 int gicv3_lpi_allocate_host_lpi(struct host_its *its,
                                 uint32_t devid, uint32_t eventid,
                                 struct vcpu *v, int virt_lpi);
+int gicv3_lpi_change_vcpu(struct domain *d, uint32_t host_lpi, int 
new_vcpu_id);
 int gicv3_lpi_drop_host_lpi(struct host_its *its,
                             uint32_t devid, uint32_t eventid,
                             uint32_t host_lpi);
-- 
2.9.0


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