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 | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c index 3332c09..773e5fb 100644 --- a/xen/arch/arm/vgic-v3-its.c +++ b/xen/arch/arm/vgic-v3-its.c @@ -726,6 +726,30 @@ 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); + if ( ret ) + goto out_unlock; + + /* Remove from the guest's ITTE. */ + if ( !write_itte_locked(its, devid, eventid, + UNMAPPED_COLLECTION, INVALID_LPI, NULL) ) + ret = -1; + +out_unlock: + 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)) @@ -758,6 +782,9 @@ 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; -- 2.9.0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel