[Xen-devel] [RFC PATCH v2 23/26] ARM: vITS: handle INVALL command

[Andre Przywara <andre.przywara@xxxxxxx>]

The INVALL command instructs an ITS to invalidate the configuration
data for all LPIs associated with a given redistributor (read: VCPU).
This is nasty to emulate exactly with our architecture, so we just scan
the pending table and inject _every_ LPI found there that got enabled.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/vgic-its.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/xen/arch/arm/vgic-its.c b/xen/arch/arm/vgic-its.c
index bcabb04..c130d98 100644
--- a/xen/arch/arm/vgic-its.c
+++ b/xen/arch/arm/vgic-its.c
@@ -297,6 +297,39 @@ out_unlock:
     return ret;
 }
 
+/* INVALL updates the per-LPI configuration status for every LPI mapped to
+ * a particular redistributor. Since our property table is referenced when
+ * needed, we don't need to sync anything, really. But we have to take care
+ * of LPIs getting enabled if there is an interrupt pending.
+ * To catch every LPI without iterating through the device table we just
+ * look for set bits in our virtual pending table and check the status of
+ * the enabled bit in the respective property table entry.
+ * This actually covers every (pending) LPI from every redistributor,
+ * but update_lpi_enabled_status() is a NOP for LPIs not being mapped
+ * to the redistributor/VCPU we are interested in.
+ */
+static int its_handle_invall(struct virt_its *its, uint64_t *cmdptr)
+{
+    uint32_t collid = its_cmd_get_collection(cmdptr);
+    struct vcpu *vcpu;
+    int vlpi = 0;
+
+    spin_lock(&its->its_lock);
+    vcpu = get_vcpu_from_collection(its, collid);
+    spin_unlock(&its->its_lock);
+
+    do {
+        vlpi = find_next_bit(vcpu->arch.vgic.pendtable,
+                             its->d->arch.vgic.nr_lpis, vlpi);
+        if (vlpi >= its->d->arch.vgic.nr_lpis)
+            break;
+
+        update_lpi_enabled_status(its, vcpu, vlpi);
+    } while (1);
+
+    return 0;
+}
+
 static int its_handle_mapc(struct virt_its *its, uint64_t *cmdptr)
 {
     uint32_t collid = its_cmd_get_collection(cmdptr);
@@ -490,6 +523,9 @@ static int vgic_its_handle_cmds(struct domain *d, struct 
virt_its *its,
         case GITS_CMD_INV:
             its_handle_inv(its, cmdptr);
            break;
+        case GITS_CMD_INVALL:
+            its_handle_invall(its, cmdptr);
+           break;
         case GITS_CMD_MAPC:
             its_handle_mapc(its, cmdptr);
             break;
-- 
2.9.0


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