> -----Original Message----- > From: George Dunlap [mailto:[email protected]] > Sent: 07 September 2018 16:26 > To: Roger Pau Monne <[email protected]>; Paul Durrant > <[email protected]> > Cc: 'Stefano Stabellini' <[email protected]>; Wei Liu > <[email protected]>; Konrad Rzeszutek Wilk <[email protected]>; > Andrew Cooper <[email protected]>; Tim (Xen.org) > <[email protected]>; Julien Grall <[email protected]>; Jan Beulich > <[email protected]>; Ian Jackson <[email protected]>; xen- > [email protected] > Subject: Re: [Xen-devel] [PATCH] tools: specifically enable VirtFS in Linux > QEMU builds > > On 09/07/2018 03:57 PM, Roger Pau Monné wrote: > > On Fri, Sep 07, 2018 at 08:35:11AM +0000, Paul Durrant wrote: > >>> -----Original Message----- > >>> From: Stefano Stabellini [mailto:[email protected]] > >>> Sent: 06 September 2018 19:12 > >>> To: Paul Durrant <[email protected]> > >>> Cc: [email protected]; Andrew Cooper > >>> <[email protected]>; George Dunlap > >>> <[email protected]>; Ian Jackson <[email protected]>; > Jan > >>> Beulich <[email protected]>; Julien Grall <[email protected]>; > Konrad > >>> Rzeszutek Wilk <[email protected]>; Stefano Stabellini > >>> <[email protected]>; Tim (Xen.org) <[email protected]>; Wei Liu > >>> <[email protected]> > >>> Subject: Re: [PATCH] tools: specifically enable VirtFS in Linux QEMU > builds > >>> > >>> On Thu, 6 Sep 2018, Paul Durrant wrote: > >>>> 9pfs support has been a documented feature since Xen 4.9, but QEMU > will > >>>> not be built with backend support unless libcap and libattr dev > packages > >>>> are installed. > >>>> > >>>> This patch modifies the README to call out those packages as pre- > >>> requisites > >>>> for Linux builds and specifically enables VirtFS in the configure line > >>>> for QEMU so that an error message is displayed if they are missing. > >>>> > >>>> Signed-off-by: Paul Durrant <[email protected]> > >>> > >>> Thank you, Paul! > >> > >> NP. I'm at the point of seriously considering a Windows frontend, which is > why I've been playing. > >> > >> BTW, as a heads-up... Before I realised QEMU was not building the > backend, I tried a modprobe of the Xen 9pfs transport module in a Linux > guest and immediately hit a kernel BUG (NULL ptr IIRC) which was apparently > down to the frontend expecting the backend to be present when its probe > routine is run, rather than deferring things until the backend goes into > InitWait (which is what a frontend generally should do). Also, it's > non-obvious > why I have to explicitly modprobe anyway... Shouldn't the module get > demand-loaded when I run mount -t 9pfs blah? > >> > >>> Do we need to do anything for the configure stuff > >>> (AC_CHECK_LIB in tools/configure.ac)? > >> > >> That's certainly a reasonable belt'n'braces approach so that folks don't > have to wait until their tools build fails to find out what they need. I'll > have a > look at that. > > > > IMO I don't think we should be duplicating the checks that QEMU > > configure already does in our configure script. The best option would > > be to run whatever external configure scripts there are together with > > our own configure script, but this is quite complicated because the > > qemu-dir might have to be fetched at the point where configure runs. > > Not the least because the dependencies may change. I think adding an > "--enable-9pfs" option which will pass on the requisite "--enable" to > qemu (such that qemu build will fail if the prereqs are not present) > makes the most sense.
I'd be happy with that if others are. Paul > > -George _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
