On Wed, Jun 30, 2010 at 3:25 AM, Herbert Poetzl <herbert@13thfloor.at>wrote: > On Tue, Jun 29, 2010 at 04:01:13PM -0700, Siv wrote: > > On Mon, Jun 28, 2010 at 5:18 PM, Herbert Poetzl <herbert@13thfloor.at > >wrote: > > > On Mon, Jun 28, 2010 at 10:12:07AM -0700, Siv wrote: > > > > Hi, > > > > > I have been looking at http://linux-vserver.org/USB_Devices to > > > > access usb device from my guest (I can't get it to work yet, > > > > but that calls for a separate discussion). > > > > > My question is - while I have steps for USB, what about other > > > > devices (say scsi drives or SD/pcmcia cards) ? > > > > basically it all boils down to the right set of > > > permissions and the proper device nodes inside > > > the guest > > > > > Do they need some special handling to be visible under guest ? > > > > there might be certain devices or drivers which > > > require more than the usual set of capabilities > > > > > Also, I may need to add user space device drivers in future > > > > and can I do it from the guest (and host would not see it) ? > > > > user space device drivers sound interesting for > > > a linux kernel, but as long as the required > > > kernel interface is available inside the guest, > > > I don't see a problem with them ... > > > > > I hope so but wanted to confirm. > > > > give it a try and let us know :) > > > Sure, will let you know when I try :) > > With the usual kernel space driver, say I open /dev/driver > make that 'device' or 'device node' ~~~~~~~~~~~~ > > from host and guest, my driver needs to restrict/limit > > accesses based on the requestor (basically host requests > > will have more privileges). > > > Can kernel can distinguish requests from host and the > > guest ? > > yes, the kernel knows (vx_check(), vx_task_xid(current)) > > best, > Herbert > Thanks. I see that host xid is always 0. vx_check(0, VS_IDENT) helps to find if it is host or guest. I think I can also do vx_check(vx_task_xid(current), VS_HOSTID). Now, from check.h (mode & VS_ADMIN) && (cid == 0)) -> Does this assume host is always the ADMIN ? (mode & VS_WATCH) && (cid == 1) -> Where is VS_WATCH used ? Just curious. --Siv-- > > > --Siv-- > > > > > > > > best, > > > Herbert > > > > > > > --Siv-- > > > >
make that 'device' or 'device node' ~~~~~~~~~~~~On Tue, Jun 29, 2010 at 04:01:13PM -0700, Siv wrote:
> On Mon, Jun 28, 2010 at 5:18 PM, Herbert Poetzl <herbert@13thfloor.at>wrote:
> > On Mon, Jun 28, 2010 at 10:12:07AM -0700, Siv wrote:
> > > Hi,
> > > I have been looking at http://linux-vserver.org/USB Devices to
> > > access usb device from my guest (I can't get it to work yet,
> > > but that calls for a separate discussion).
> > > My question is - while I have steps for USB, what about other
> > > devices (say scsi drives or SD/pcmcia cards) ?
> > basically it all boils down to the right set of
> > permissions and the proper device nodes inside
> > the guest
> > > Do they need some special handling to be visible under guest ?
> > there might be certain devices or drivers which
> > require more than the usual set of capabilities
> > > Also, I may need to add user space device drivers in future
> > > and can I do it from the guest (and host would not see it) ?
> > user space device drivers sound interesting for
> > a linux kernel, but as long as the required
> > kernel interface is available inside the guest,
> > I don't see a problem with them ...
> > > I hope so but wanted to confirm.
> > give it a try and let us know :)
> Sure, will let you know when I try :)
> With the usual kernel space driver, say I open /dev/driver
> from host and guest, my driver needs to restrict/limityes, the kernel knows (vx check(), vx task xid(current))
> accesses based on the requestor (basically host requests
> will have more privileges).
> Can kernel can distinguish requests from host and the
> guest ?
best,
Herbert
> --Siv--
>
> >
> > best,
> > Herbert
> >
> > > --Siv--
> >