Hi Andre,
On 11/05/17 18:53, Andre Przywara wrote:
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.przyw...@arm.com>
---
xen/arch/arm/vgic-v3-its.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
index ef7c78f..f7a8d77 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -723,6 +723,27 @@ 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);
+ int ret;
+
+ spin_lock(&its->its_lock);
+
+ /* Remove from the radix tree and remove the host entry. */
+ ret = its_discard_event(its, devid, eventid);
+
+ /* Remove from the guest's ITTE. */
+ if ( ret || write_itte_locked(its, devid, eventid,
+ UNMAPPED_COLLECTION, INVALID_LPI, NULL) )
I am not sure to fully understand this if. If ret is not NULL you
override it and never call write_itte_locked.
Is it what you wanted? If so, then probably a bit more documentation
would be useful to explain why writte_itte_locked is skipped.
+ ret = -1;
+
+ spin_unlock(&its->its_lock);
+
+ return ret;
+}
+
#define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12)
#define ITS_CMD_OFFSET(reg) ((reg) & GENMASK(19, 5))
@@ -755,6 +776,9 @@ 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;
Cheers,
--
Julien Grall
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