linux-kernel - RE: [PATCH 1/1] Drivers: hv: vmbus: Add device and vendor ID to vmbus devices

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 18 Dec 2014 00:46:36 +0000
From:	KY Srinivasan <kys@...rosoft.com>
To:	Greg KH <gregkh@...uxfoundation.org>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devel@...uxdriverproject.org" <devel@...uxdriverproject.org>,
	"olaf@...fle.de" <olaf@...fle.de>,
	"apw@...onical.com" <apw@...onical.com>,
	"jasowang@...hat.com" <jasowang@...hat.com>
Subject: RE: [PATCH 1/1] Drivers: hv: vmbus: Add device and vendor ID to vmbus
 devices



> -----Original Message-----
> From: Greg KH [mailto:gregkh@...uxfoundation.org]
> Sent: Wednesday, December 17, 2014 4:17 PM
> To: KY Srinivasan
> Cc: linux-kernel@...r.kernel.org; devel@...uxdriverproject.org;
> olaf@...fle.de; apw@...onical.com; jasowang@...hat.com
> Subject: Re: [PATCH 1/1] Drivers: hv: vmbus: Add device and vendor ID to
> vmbus devices
> 
> On Wed, Dec 17, 2014 at 02:52:24PM -0800, K. Y. Srinivasan wrote:
> > Add vendor and device ID attributes to vmbus devices. This would allow
> > us to support vmbus based devices that can support guest RDMA.
> >
> > Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
> > ---
> >  drivers/hv/vmbus_drv.c |   20 ++++++++++++++++++++
> >  include/linux/hyperv.h |    2 ++
> >  2 files changed, 22 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index
> > 4d6b269..215aac9 100644
> > --- a/drivers/hv/vmbus_drv.c
> > +++ b/drivers/hv/vmbus_drv.c
> > @@ -385,6 +385,24 @@ static ssize_t in_write_bytes_avail_show(struct
> > device *dev,  }  static DEVICE_ATTR_RO(in_write_bytes_avail);
> >
> > +static ssize_t vendor_show(struct device *dev,
> > +			   struct device_attribute *dev_atttr,
> > +			   char *buf)
> > +{
> > +	struct hv_device *hv_dev = device_to_hv_device(dev);
> > +	return sprintf(buf, "0x%x\n", hv_dev->vendor_id); } static
> > +DEVICE_ATTR_RO(vendor);
> > +
> > +static ssize_t device_show(struct device *dev,
> > +			   struct device_attribute *dev_atttr,
> > +			   char *buf)
> > +{
> > +	struct hv_device *hv_dev = device_to_hv_device(dev);
> > +	return sprintf(buf, "0x%x\n", hv_dev->device_id); } static
> > +DEVICE_ATTR_RO(device);
> > +
> >  /* Set up per device attributes in /sys/bus/vmbus/devices/<bus
> > device> */  static struct attribute *vmbus_attrs[] = {
> >  	&dev_attr_id.attr,
> > @@ -409,6 +427,8 @@ static struct attribute *vmbus_attrs[] = {
> >  	&dev_attr_in_write_index.attr,
> >  	&dev_attr_in_read_bytes_avail.attr,
> >  	&dev_attr_in_write_bytes_avail.attr,
> > +	&dev_attr_vendor.attr,
> > +	&dev_attr_device.attr,
> >  	NULL,
> >  };
> >  ATTRIBUTE_GROUPS(vmbus);
> > diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index
> > 476c685..6fe4dfe 100644
> > --- a/include/linux/hyperv.h
> > +++ b/include/linux/hyperv.h
> > @@ -891,6 +891,8 @@ struct hv_device {
> >
> >  	/* the device instance id of this device */
> >  	uuid_le dev_instance;
> > +	u16 vendor_id;
> > +	u16 device_id;
> >
> >  	struct device device;
> >
> 
> You are adding new sysfs files without proper Documentation/ABI/ updates
> as well?  You know better than that...
> 
> And I don't see anything setting these fields, seems kind of pointless as-is,
> right?

Greg, 

You are right, nothing sets these fields today but I am working on a guest infiniband  RDMA driver that  uses this.
This driver registers itself as an infiniband HW driver and the vendor device id is needed for IHV libraries to discover this driver from user mode.  In some sense, these two fields are equivalent to the vendor ID and device of standard PCI devices as this VMBUS based infiniband driver needs to masquerade as the infiniband card in the host that is being presented to the guest.

I can resubmit this patch with the additional documentation.

Regards,

K. Y



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/