From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com ([205.139.110.61]:31683 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2392913AbfJXDbr (ORCPT ); Wed, 23 Oct 2019 23:31:47 -0400 Subject: Re: [PATCH V5 2/6] modpost: add support for mdev class id References: <20191023130752.18980-1-jasowang@redhat.com> <20191023130752.18980-3-jasowang@redhat.com> <20191023154245.32e4fa49@x1.home> From: Jason Wang Message-ID: <555a101e-0ed1-2e9d-c1a4-e3b37d76bd18@redhat.com> Date: Thu, 24 Oct 2019 11:31:04 +0800 MIME-Version: 1.0 In-Reply-To: <20191023154245.32e4fa49@x1.home> Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-s390-owner@vger.kernel.org List-ID: To: Alex Williamson Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, kwankhede@nvidia.com, mst@redhat.com, tiwei.bie@intel.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, cohuck@redhat.com, maxime.coquelin@redhat.com, cunming.liang@intel.com, zhihong.wang@intel.com, rob.miller@broadcom.com, xiao.w.wang@intel.com, haotian.wang@sifive.com, zhenyuw@linux.intel.com, zhi.a.wang@intel.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, airlied@linux.ie, daniel@ffwll.ch, farman@linux.ibm.com, pasic@linux.ibm.com, sebott@linux.ibm.com, oberpar@linux.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com, borntraeger@de.ibm.com, akrowiak@linux.ibm.com, freude@linux.ibm.com, lingshan.zhu@intel.com, idos@mellanox.com, eperezma@redhat.com, lulu@redhat.com, parav@mellanox.com, christophe.de.dinechin@gmail.com, kevin.tian@intel.com, stefanha@redhat.com On 2019/10/24 =E4=B8=8A=E5=8D=885:42, Alex Williamson wrote: > On Wed, 23 Oct 2019 21:07:48 +0800 > Jason Wang wrote: > >> Add support to parse mdev class id table. >> >> Reviewed-by: Parav Pandit >> Signed-off-by: Jason Wang >> --- >> drivers/vfio/mdev/vfio_mdev.c | 2 ++ >> scripts/mod/devicetable-offsets.c | 3 +++ >> scripts/mod/file2alias.c | 10 ++++++++++ >> 3 files changed, 15 insertions(+) >> >> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev= .c >> index 7b24ee9cb8dd..cb701cd646f0 100644 >> --- a/drivers/vfio/mdev/vfio_mdev.c >> +++ b/drivers/vfio/mdev/vfio_mdev.c >> @@ -125,6 +125,8 @@ static const struct mdev_class_id id_table[] =3D { >> =09{ 0 }, >> }; >> =20 >> +MODULE_DEVICE_TABLE(mdev, id_table); >> + > Two questions, first we have: > > #define MODULE_DEVICE_TABLE(type, name) \ > extern typeof(name) __mod_##type##__##name##_device_table \ > __attribute__ ((unused, alias(__stringify(name)))) > > Therefore we're defining __mod_mdev__id_table_device_table with alias > id_table. When the virtio mdev bus driver is added in 5/6 it uses the > same name value. I see virtio types all register this way (virtio, > id_table), so I assume there's no conflict, but pci types mostly (not > entirely) seem to use unique names. Is there a preference to one way > or the other or it simply doesn't matter? It looks to me that those symbol were local, so it doesn't matter. But=20 if you wish I can switch to use unique name. > >> static struct mdev_driver vfio_mdev_driver =3D { >> =09.name=09=3D "vfio_mdev", >> =09.probe=09=3D vfio_mdev_probe, >> diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable= -offsets.c >> index 054405b90ba4..6cbb1062488a 100644 >> --- a/scripts/mod/devicetable-offsets.c >> +++ b/scripts/mod/devicetable-offsets.c >> @@ -231,5 +231,8 @@ int main(void) >> =09DEVID(wmi_device_id); >> =09DEVID_FIELD(wmi_device_id, guid_string); >> =20 >> +=09DEVID(mdev_class_id); >> +=09DEVID_FIELD(mdev_class_id, id); >> + >> =09return 0; >> } >> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c >> index c91eba751804..d365dfe7c718 100644 >> --- a/scripts/mod/file2alias.c >> +++ b/scripts/mod/file2alias.c >> @@ -1335,6 +1335,15 @@ static int do_wmi_entry(const char *filename, voi= d *symval, char *alias) >> =09return 1; >> } >> =20 >> +/* looks like: "mdev:cN" */ >> +static int do_mdev_entry(const char *filename, void *symval, char *alia= s) >> +{ >> +=09DEF_FIELD(symval, mdev_class_id, id); >> + >> +=09sprintf(alias, "mdev:c%02X", id); > A lot of entries call add_wildcard() here, should we? Sorry for the > basic questions, I haven't played in this code. Thanks, It's really good question. My understanding is we won't have a module=20 that can deal with all kinds of classes like CLASS_ID_ANY. So there's=20 probably no need for the wildcard. Thanks > > Alex > >> +=09return 1; >> +} >> + >> /* Does namelen bytes of name exactly match the symbol? */ >> static bool sym_is(const char *name, unsigned namelen, const char *sym= bol) >> { >> @@ -1407,6 +1416,7 @@ static const struct devtable devtable[] =3D { >> =09{"typec", SIZE_typec_device_id, do_typec_entry}, >> =09{"tee", SIZE_tee_client_device_id, do_tee_entry}, >> =09{"wmi", SIZE_wmi_device_id, do_wmi_entry}, >> +=09{"mdev", SIZE_mdev_class_id, do_mdev_entry}, >> }; >> =20 >> /* Create MODULE_ALIAS() statements.