| Message ID | 20170509192858.17623-1-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 9, 2017 at 9:28 PM, Stefan Hajnoczi <stefanha@redhat.com> wrote: > > Note that the "reserved for local use" range in > Documentation/admin-guide/devices.txt is incorrect. The userio driver > already occupies part of that range. I've updated the documentation > accordingly. ... > diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt > index c9cea2e..5fe3480 100644 > --- a/Documentation/admin-guide/devices.txt > +++ b/Documentation/admin-guide/devices.txt > @@ -369,8 +369,9 @@ > 237 = /dev/loop-control Loopback control device > 238 = /dev/vhost-net Host kernel accelerator for virtio net > 239 = /dev/uhid User-space I/O driver support for HID subsystem > + 241 = /dev/vhost-vsock Host kernel driver for virtio vsock It seems like you intended to add the 240 documentation here as well but then sent the patch without it. Arnd
On Wed, May 10, 2017 at 10:01:36AM +0200, Arnd Bergmann wrote: > On Tue, May 9, 2017 at 9:28 PM, Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > Note that the "reserved for local use" range in > > Documentation/admin-guide/devices.txt is incorrect. The userio driver > > already occupies part of that range. I've updated the documentation > > accordingly. > ... > > diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt > > index c9cea2e..5fe3480 100644 > > --- a/Documentation/admin-guide/devices.txt > > +++ b/Documentation/admin-guide/devices.txt > > @@ -369,8 +369,9 @@ > > 237 = /dev/loop-control Loopback control device > > 238 = /dev/vhost-net Host kernel accelerator for virtio net > > 239 = /dev/uhid User-space I/O driver support for HID subsystem > > + 241 = /dev/vhost-vsock Host kernel driver for virtio vsock > > It seems like you intended to add the 240 documentation here as well but > then sent the patch without it. Thanks, will fix in v2. Stefan
diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt index c9cea2e..5fe3480 100644 --- a/Documentation/admin-guide/devices.txt +++ b/Documentation/admin-guide/devices.txt @@ -369,8 +369,9 @@ 237 = /dev/loop-control Loopback control device 238 = /dev/vhost-net Host kernel accelerator for virtio net 239 = /dev/uhid User-space I/O driver support for HID subsystem + 241 = /dev/vhost-vsock Host kernel driver for virtio vsock - 240-254 Reserved for local use + 242-254 Reserved for local use 255 Reserved for MISC_DYNAMIC_MINOR 11 char Raw keyboard device (Linux/SPARC only) diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h index 762b5fe..58751ea 100644 --- a/include/linux/miscdevice.h +++ b/include/linux/miscdevice.h @@ -54,6 +54,7 @@ #define VHOST_NET_MINOR 238 #define UHID_MINOR 239 #define USERIO_MINOR 240 +#define VHOST_VSOCK_MINOR 241 #define MISC_DYNAMIC_MINOR 255 struct device; diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 44eed8e..53e3e95 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -701,7 +701,7 @@ static const struct file_operations vhost_vsock_fops = { }; static struct miscdevice vhost_vsock_misc = { - .minor = MISC_DYNAMIC_MINOR, + .minor = VHOST_VSOCK_MINOR, .name = "vhost-vsock", .fops = &vhost_vsock_fops, }; @@ -773,3 +773,5 @@ module_exit(vhost_vsock_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Asias He"); MODULE_DESCRIPTION("vhost transport for vsock "); +MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR); +MODULE_ALIAS("devname:vhost-vsock");
Vhost-vsock is a software device so there is no probe call that causes the driver to register its misc char device node. This creates a chicken and egg problem: userspace applications must open /dev/vhost-vsock to use the driver but the file doesn't exist until the kernel module has been loaded. Use the devname modalias mechanism so that /dev/vhost-vsock is created at boot. The vhost_vsock kernel module is automatically loaded when the first application opens /dev/host-vsock. Note that the "reserved for local use" range in Documentation/admin-guide/devices.txt is incorrect. The userio driver already occupies part of that range. I've updated the documentation accordingly. Cc: device@lanana.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- Documentation/admin-guide/devices.txt | 3 ++- include/linux/miscdevice.h | 1 + drivers/vhost/vsock.c | 4 +++- 3 files changed, 6 insertions(+), 2 deletions(-)