Mailing List Archive: [Xen-merge] Missing devpts in domU / i8237.c issue

[Xen-merge] Missing devpts in domU / i8237.c issue

Jan 15, 2006, 2:22 AM

Post #1 of 4 (480 views)

Hi all,

hopefully my question isn't too dump and you don't hit me to hard for it:

I've checked out the 'linux-2.6-merge.hg' tree. Everything fine so far except
two things:

1) Why is devpts disabled for domUs? The ssh daemon will not work without. Or
do i have missed something? How do i have to setup the domU to get the sshd
(openssh-4.2p1) working. With the xen-3.0.0 release, it works fine.

2) When compiling the kernel the compile fails with error message:

make mrproper
make menuconfig
make
...
arch/i386/kernel/built-in.o: In function `i8237A_resume':
i8237.c:(.text+0x7751): undefined reference to `smp_processor_id'
i8237.c:(.text+0x77b1): undefined reference to `smp_processor_id'
make: *** [.tmp_vmlinux1] Fehler 1

This occures if SMP is set off cause the machine does have only one CPU.
Adding "#include <linux/smp.h>" to "arch/i386/kernel/i8237.c" makes it
compilable. Is that a correct fix? Btw. i'm using a gcc-4.0.2.

Thank you for giving me some hints

Thomas

___________________________________________________________
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de

_______________________________________________
Xen-merge mailing list
Xen-merge@lists.xensource.com
http://lists.xensource.com/xen-merge

Re: [Xen-merge] Missing devpts in domU / i8237.c issue [ In reply to ]

vincent.hanquez at cl

Jan 18, 2006, 6:51 AM

Post #2 of 4 (467 views)

Permalink

On Sun, Jan 15, 2006 at 10:22:50AM +0100, Thomas Trepl wrote:
> 1) Why is devpts disabled for domUs? The ssh daemon will not work without. Or
> do i have missed something? How do i have to setup the domU to get the sshd
> (openssh-4.2p1) working. With the xen-3.0.0 release, it works fine.

the following patch should do the job (sent to the maintainer as well):

diff -r bb555541ec84 drivers/Kconfig
--- a/drivers/Kconfig Fri Jan 13 19:47:57 2006 +0100
+++ b/drivers/Kconfig Wed Jan 18 13:48:28 2006 +0000
@@ -49,9 +49,11 @@
# input before char - char/joystick depends on it. As does USB.

source "drivers/input/Kconfig"
+endif

source "drivers/char/Kconfig"

+if !XEN || XEN_PHYSDEV_ACCESS
source "drivers/i2c/Kconfig"

source "drivers/w1/Kconfig"

> 2) When compiling the kernel the compile fails with error message:
> [snip]
> This occures if SMP is set off cause the machine does have only one CPU.
> Adding "#include <linux/smp.h>" to "arch/i386/kernel/i8237.c" makes it
> compilable. Is that a correct fix? Btw. i'm using a gcc-4.0.2.

This is not the correct fix since i8237 has nothing to do with SMP.
the problem lies somewhere in the include dependancy.

asm-i386/mach-xen/asm/system.h <- included by spinlock.h <- include by dma.h
need some linux/smp.h definition
I failed to see what is the good fix right now ..

you can compile a SMP kernel for the moment (and add CONFIG_SMP_ALT if
you are really worried of the performance)

Cheers,
--
Vincent Hanquez

_______________________________________________
Xen-merge mailing list
Xen-merge@lists.xensource.com
http://lists.xensource.com/xen-merge

Re: [Xen-merge] Missing devpts in domU / i8237.c issue [ In reply to ]

ak at suse

Jan 18, 2006, 6:58 AM

Post #3 of 4 (463 views)

Permalink

On Wednesday 18 January 2006 14:51, Vincent Hanquez wrote:
> On Sun, Jan 15, 2006 at 10:22:50AM +0100, Thomas Trepl wrote:
> > 1) Why is devpts disabled for domUs? The ssh daemon will not work
> > without. Or do i have missed something? How do i have to setup the domU
> > to get the sshd (openssh-4.2p1) working. With the xen-3.0.0 release, it
> > works fine.
>
> the following patch should do the job (sent to the maintainer as well):

Which is ugly and they would rightly reject it. The right approach would
be to make sure that all such subsystems are dependent on appropiate
symbols (PCI etc.) and just don't define them for kernels without hardware
access.

-Andi

_______________________________________________
Xen-merge mailing list
Xen-merge@lists.xensource.com
http://lists.xensource.com/xen-merge

Re: [Xen-merge] Missing devpts in domU / i8237.c issue [ In reply to ]

vincent.hanquez at cl

Jan 18, 2006, 9:43 AM

Post #4 of 4 (466 views)

Permalink

On Wed, Jan 18, 2006 at 02:58:36PM +0100, Andi Kleen wrote:
> > the following patch should do the job (sent to the maintainer as well):
>
> Which is ugly and they would rightly reject it.

If as "they" you refer to the linux maintainers, I would totally agree
with your point. However this has nothing to do here, it just modify
an (already) ugly approch to fix a problem with DEVPTS that a lots user
are seeing.

> The right approach would be to make sure that all such subsystems are
> dependent on appropiate symbols (PCI etc.) and just don't define them
> for kernels without hardware access.

It actually make it as such, as to reallow one of the subsystem we
desactivate the ugly way to do that.

Removing all ifdef hooks into drivers/Kconfig is a lot more intrusive
approch (maybe reuse UML hooks into a more generic name, touch lots of
drivers/.../Kconfig, and a lots of headache to have the right
dependancies) and doesn't fit into the quickly fix people current
problem with linux-2.6.15-xen.

--
Vincent Hanquez

_______________________________________________
Xen-merge mailing list
Xen-merge@lists.xensource.com
http://lists.xensource.com/xen-merge