Messages in this thread | | | Subject | Re: [PATCH V5 2/6] modpost: add support for mdev class id | From | Jason Wang <> | Date | Fri, 25 Oct 2019 09:44:05 +0800 |
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On 2019/10/25 上午3:54, Alex Williamson wrote: > On Thu, 24 Oct 2019 11:31:04 +0800 > Jason Wang <jasowang@redhat.com> wrote: > >> On 2019/10/24 上午5:42, Alex Williamson wrote: >>> On Wed, 23 Oct 2019 21:07:48 +0800 >>> Jason Wang <jasowang@redhat.com> wrote: >>> >>>> Add support to parse mdev class id table. >>>> >>>> Reviewed-by: Parav Pandit <parav@mellanox.com> >>>> Signed-off-by: Jason Wang <jasowang@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.
Yes, to be more safe I will switch to unique names here.
> >>>> 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,
Yes, so I will add that for future extension.
Thanks
> > Alex >
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