linux-kernel - RE: RFC: (re-)binding the VFIO platform driver to a platform device

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

Date:	Thu, 10 Oct 2013 13:43:22 +0000
From:	Yoder Stuart-B08248 <B08248@...escale.com>
To:	Bhushan Bharat-R65777 <R65777@...escale.com>,
	Wood Scott-B07421 <B07421@...escale.com>
CC:	Kim Phillips <kim.phillips@...aro.org>,
	Christoffer Dall <christoffer.dall@...aro.org>,
	Alex Williamson <alex.williamson@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"a.motakis@...tualopensystems.com" <a.motakis@...tualopensystems.com>,
	"agraf@...e.de" <agraf@...e.de>,
	Sethi Varun-B16395 <B16395@...escale.com>,
	"peter.maydell@...aro.org" <peter.maydell@...aro.org>,
	"santosh.shukla@...aro.org" <santosh.shukla@...aro.org>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>
Subject: RE: RFC: (re-)binding the VFIO platform driver to a platform device

> I am trying to understand what you are proposing here (example "DEVICE"
> can be handled by "DRIVER1" and "VFIO-PLATFORM-DRIVER"):
>  - By default drv->explicit_bind_only will be clear in all drivers.
>  - By default device->explicit_bind_only will also be clear for all
> devices.
>  - On boot, matching devices will bound to the respective driver (DEVICE
> >==> DRIVER1).
>    This will never bound with VFIO-PLATFORM-DRIVER. So far same as
> before.
>  - Via Sysfs interface set drv->explicit_bind_only for VFIO-PLATFORM-
> DRIVER.

No.  VFIO-PLATFORM-DRIVER is _always_ explicit_bind_only and thus will be
statically set in the driver.  See Kim's patch.

>  - Then for the devices user want, set device->explicit_bind_only.
>  - unbind DEVICE from DRIVER1
>  - bind DEVICE with VFIO-PLATFORM-DRIVER. This time it will be successful
> because (device->explicit_bind_only && drv->explicit_bind_only) is set.
>  - Now when done, unbind the DEVICE from VFIO-PLATFORM-DRIVER.
>  - Now user can re-bind the device with either DRIVER1 or VFIO-PLATFORM-
> DRIVER.
>  - Now once drv->explicit_bind_only is set in VFIO-PLATFORM-DRIVER, and a
> new device comes (device - hotplug) then can gets bound to matching drive
> and not with VFIO-PLATFORM-DRIVER.

Otherwise, it looks correct to me.

Stuart