@@ -280,8 +280,8 @@ static bool write_itte_locked(struct virt_its *its, uint32_t devid,
* This function takes care of the locking by taking the its_lock itself, so
* a caller shall not hold this. Before returning, the lock is dropped again.
*/
-bool write_itte(struct virt_its *its, uint32_t devid, uint32_t evid,
- uint32_t collid, uint32_t vlpi, struct vcpu **vcpu_ptr)
+static bool write_itte(struct virt_its *its, uint32_t devid, uint32_t evid,
+ uint32_t collid, uint32_t vlpi, struct vcpu **vcpu_ptr)
{
bool ret;
@@ -581,6 +581,35 @@ out_unlock:
return ret;
}
+static int its_handle_discard(struct virt_its *its, uint64_t *cmdptr)
+{
+ uint32_t devid = its_cmd_get_deviceid(cmdptr);
+ uint32_t eventid = its_cmd_get_id(cmdptr);
+ struct pending_irq *pirq;
+ struct vcpu *vcpu;
+ uint32_t vlpi;
+
+ if ( !read_itte(its, devid, eventid, &vcpu, &vlpi) )
+ return -1;
+
+ pirq = its->d->arch.vgic.handler->lpi_to_pending(its->d, vlpi);
+ if ( pirq )
+ {
+ clear_bit(GIC_IRQ_GUEST_QUEUED, &pirq->status);
+ gic_remove_from_queues(vcpu, vlpi);
+ }
+
+ if ( !write_itte(its, devid, eventid, UNMAPPED_COLLECTION, INVALID_LPI,
+ NULL) )
+ return -1;
+
+ if ( !gicv3_assign_guest_event(its->d, its->doorbell_address,
+ devid, eventid, NULL, 0) )
+ return -1;
+
+ return 0;
+}
+
#define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12)
/*
@@ -613,6 +642,9 @@ static int vgic_its_handle_cmds(struct domain *d, struct virt_its *its)
case GITS_CMD_CLEAR:
ret = its_handle_clear(its, command);
break;
+ case GITS_CMD_DISCARD:
+ ret = its_handle_discard(its, command);
+ break;
case GITS_CMD_INT:
ret = its_handle_int(its, command);
break;
The DISCARD command drops the connection between a DeviceID/EventID and an LPI/collection pair. We mark the respective structure entries as not allocated and make sure that any queued IRQs are removed. Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- xen/arch/arm/vgic-v3-its.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-)