On Tue, Aug 16, 2016 at 05:51:06PM +0100, Andre Przywara wrote: > When a guest wants to map a device-ID/event-ID combination that is > already mapped, we may end up in a situation where an LPI is never > "put", thus never being freed. > Since the GICv3 spec says that mapping an already mapped LPI is > UNPREDICTABLE, lets just bail out early in this situation to avoid > any potential leaks. > > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> > --- > virt/kvm/arm/vgic/vgic-its.c | 27 +++++++++++++-------------- > 1 file changed, 13 insertions(+), 14 deletions(-) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index 9533080..4660a7d 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -731,7 +731,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its, > u32 device_id = its_cmd_get_deviceid(its_cmd); > u32 event_id = its_cmd_get_id(its_cmd); > u32 coll_id = its_cmd_get_collection(its_cmd); > - struct its_itte *itte, *new_itte = NULL; > + struct its_itte *itte; > struct its_device *device; > struct its_collection *collection, *new_coll = NULL; > int lpi_nr; > @@ -749,6 +749,10 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its, > lpi_nr >= max_lpis_propbaser(kvm->arch.vgic.propbaser)) > return E_ITS_MAPTI_PHYSICALID_OOR; > > + /* If there is an existing mapping, behavior is UNPREDICTABLE. */ > + if (find_itte(its, device_id, event_id)) > + return 0; > + By the way, this made me think how these errors are handled, and unless I'm mistaken, the return value from vgic_its_handle_command() is simply discarded, so even when we return things like -ENOMEM, this is just ignored? Is this really the intention? Thanks, -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
