Alex Williamson
2019-Oct-23 21:42 UTC
[PATCH V5 2/6] modpost: add support for mdev class id
On Wed, 23 Oct 2019 21:07:48 +0800 Jason Wang <jasowang at redhat.com> wrote:> Add support to parse mdev class id table. > > Reviewed-by: Parav Pandit <parav at mellanox.com> > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > 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[] = { > { 0 }, > }; > > +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?> static struct mdev_driver vfio_mdev_driver = { > .name = "vfio_mdev", > .probe = 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) > DEVID(wmi_device_id); > DEVID_FIELD(wmi_device_id, guid_string); > > + DEVID(mdev_class_id); > + DEVID_FIELD(mdev_class_id, id); > + > return 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, void *symval, char *alias) > return 1; > } > > +/* looks like: "mdev:cN" */ > +static int do_mdev_entry(const char *filename, void *symval, char *alias) > +{ > + DEF_FIELD(symval, mdev_class_id, id); > + > + sprintf(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, Alex> + return 1; > +} > + > /* Does namelen bytes of name exactly match the symbol? */ > static bool sym_is(const char *name, unsigned namelen, const char *symbol) > { > @@ -1407,6 +1416,7 @@ static const struct devtable devtable[] = { > {"typec", SIZE_typec_device_id, do_typec_entry}, > {"tee", SIZE_tee_client_device_id, do_tee_entry}, > {"wmi", SIZE_wmi_device_id, do_wmi_entry}, > + {"mdev", SIZE_mdev_class_id, do_mdev_entry}, > }; > > /* Create MODULE_ALIAS() statements.
On 2019/10/24 ??5:42, Alex Williamson wrote:> On Wed, 23 Oct 2019 21:07:48 +0800 > Jason Wang <jasowang at redhat.com> wrote: > >> Add support to parse mdev class id table. >> >> Reviewed-by: Parav Pandit <parav at mellanox.com> >> Signed-off-by: Jason Wang <jasowang at redhat.com> >> --- >> 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[] = { >> { 0 }, >> }; >> >> +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 if you wish I can switch to use unique name.> >> static struct mdev_driver vfio_mdev_driver = { >> .name = "vfio_mdev", >> .probe = 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) >> DEVID(wmi_device_id); >> DEVID_FIELD(wmi_device_id, guid_string); >> >> + DEVID(mdev_class_id); >> + DEVID_FIELD(mdev_class_id, id); >> + >> return 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, void *symval, char *alias) >> return 1; >> } >> >> +/* looks like: "mdev:cN" */ >> +static int do_mdev_entry(const char *filename, void *symval, char *alias) >> +{ >> + DEF_FIELD(symval, mdev_class_id, id); >> + >> + sprintf(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 that can deal with all kinds of classes like CLASS_ID_ANY. So there's probably no need for the wildcard. Thanks> > Alex > >> + return 1; >> +} >> + >> /* Does namelen bytes of name exactly match the symbol? */ >> static bool sym_is(const char *name, unsigned namelen, const char *symbol) >> { >> @@ -1407,6 +1416,7 @@ static const struct devtable devtable[] = { >> {"typec", SIZE_typec_device_id, do_typec_entry}, >> {"tee", SIZE_tee_client_device_id, do_tee_entry}, >> {"wmi", SIZE_wmi_device_id, do_wmi_entry}, >> + {"mdev", SIZE_mdev_class_id, do_mdev_entry}, >> }; >> >> /* Create MODULE_ALIAS() statements.
Alex Williamson
2019-Oct-24 19:54 UTC
[PATCH V5 2/6] modpost: add support for mdev class id
On Thu, 24 Oct 2019 11:31:04 +0800 Jason Wang <jasowang at redhat.com> wrote:> On 2019/10/24 ??5:42, Alex Williamson wrote: > > On Wed, 23 Oct 2019 21:07:48 +0800 > > Jason Wang <jasowang at redhat.com> wrote: > > > >> Add support to parse mdev class id table. > >> > >> Reviewed-by: Parav Pandit <parav at mellanox.com> > >> Signed-off-by: Jason Wang <jasowang at redhat.com> > >> --- > >> 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[] = { > >> { 0 }, > >> }; > >> > >> +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 > if you wish I can switch to use unique name.I don't have a strong opinion, I'm just trying to make sure we're not doing something obviously broken.> >> static struct mdev_driver vfio_mdev_driver = { > >> .name = "vfio_mdev", > >> .probe = 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) > >> DEVID(wmi_device_id); > >> DEVID_FIELD(wmi_device_id, guid_string); > >> > >> + DEVID(mdev_class_id); > >> + DEVID_FIELD(mdev_class_id, id); > >> + > >> return 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, void *symval, char *alias) > >> return 1; > >> } > >> > >> +/* looks like: "mdev:cN" */ > >> +static int do_mdev_entry(const char *filename, void *symval, char *alias) > >> +{ > >> + DEF_FIELD(symval, mdev_class_id, id); > >> + > >> + sprintf(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 > that can deal with all kinds of classes like CLASS_ID_ANY. So there's > probably no need for the wildcard.The comment for add_wildcard() indicates future extension, so it's hard to know what we might need in the future until we do need it. The majority of modules.alias entries on my laptop (even if I exclude pci aliases) end with a wildcard. Thanks, Alex