Bruce Edge
2010-Jun-29 22:05 UTC
[Xen-devel] Can I use SGI''s kdb with a dom0 pv-ops kernel?
I asked this a few weeks ago but didn''t get a response, so at the risk of being a nag, I''ll abbreviate and restate. I know there are other Xen specific debuggers, but I want to know if there''s any reason why SGI''s kdb, http://oss.sgi.com/projects/kdb, should not be included in a dom0 pv-ops kernel? While the patches apply cleanly and build, the result is that one drops into kdb on an oops the serial keyboard is non-functional. Is this a problem inherent in including an incompatible debugger, or perhaps just something wrong in a .config? Does anyone else use this debugger for dom0 work ? Thanks -Bruce _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Konrad Rzeszutek Wilk
2010-Jun-30 16:11 UTC
Re: [Xen-devel] Can I use SGI''s kdb with a dom0 pv-ops kernel?
On Tue, Jun 29, 2010 at 03:05:42PM -0700, Bruce Edge wrote:> I asked this a few weeks ago but didn''t get a response, so at the risk of > being a nag, I''ll abbreviate and restate. > > I know there are other Xen specific debuggers, but I want to know if there''s > any reason why SGI''s kdb, http://oss.sgi.com/projects/kdb, should not be > included in a dom0 pv-ops kernel?Upstream is integrating one that I think is in 2.6.33 or 2.6.34. So when we rev up that we will get it for free.> > While the patches apply cleanly and build, the result is that one drops into > kdb on an oops the serial keyboard is non-functional. > Is this a problem inherent in including an incompatible debugger, or perhaps > just something wrong in a .config?What is your serial setup? Are you using the serial console also for Xen? Is the serial console that Dom0 sees usuable outside kdb? As in, can you use a null modem connection and poke Dom0 via that?> > Does anyone else use this debugger for dom0 work ?I haven''t used it. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Bruce Edge
2010-Jun-30 16:44 UTC
Re: [Xen-devel] Can I use SGI''s kdb with a dom0 pv-ops kernel?
On Wed, Jun 30, 2010 at 9:11 AM, Konrad Rzeszutek Wilk < konrad.wilk@oracle.com> wrote:> On Tue, Jun 29, 2010 at 03:05:42PM -0700, Bruce Edge wrote: > > I asked this a few weeks ago but didn''t get a response, so at the risk of > > being a nag, I''ll abbreviate and restate. > > > > I know there are other Xen specific debuggers, but I want to know if > there''s > > any reason why SGI''s kdb, http://oss.sgi.com/projects/kdb, should not be > > included in a dom0 pv-ops kernel? > > Upstream is integrating one that I think is in 2.6.33 > or 2.6.34. So when we rev up that we will get it for free. >Which upstream source is doing this integration? I''m not seeing any reference to it on http://kernelnewbies.org/Linux_2_6_33 or http://kernelnewbies.org/Linux_2_6_34> > > > While the patches apply cleanly and build, the result is that one drops > into > > kdb on an oops the serial keyboard is non-functional. > > Is this a problem inherent in including an incompatible debugger, or > perhaps > > just something wrong in a .config? > > What is your serial setup?Virtual direct connect via iLO.> Are you using the serial console also for Xen?Yes> Is the serial console that Dom0 sees usuable outside kdb?Yes> As in, can you use a null modem connection and poke Dom0 via that? >Yep. The main connection to these boxes is the serial port. The kernel cmdline has "console=hvc0,115200n8" so I get boot output on it, I''m using "exec /sbin/getty -8 38400 hvc0" to get a login on the serial console, which works fine. The 3xCtrl-A also works. It''s only KDB that doesn''t like it. It appears kdb can output to the console but cannot read from it. These are the kdb patch files I used: (from http://oss.sgi.com/projects/kdb) -r--r--r-- 1 bedge wlvusers 199234 2010-06-22 11:22 kdb-v4.4-2.6.32-common-3.bz2 -r--r--r-- 1 bedge wlvusers 136442 2010-06-22 11:22 kdb-v4.4-2.6.32-x86-3.bz2 .config changes: CONFIG_KDB=y CONFIG_KDB_MODULES=y # CONFIG_KDB_OFF is not set CONFIG_KDB_CONTINUE_CATASTROPHIC=2> > > > Does anyone else use this debugger for dom0 work ? > > I haven''t used it. >Thanks for the info Konrad. -Bruce _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Konrad Rzeszutek Wilk
2010-Jun-30 17:07 UTC
Re: [Xen-devel] Can I use SGI''s kdb with a dom0 pv-ops kernel?
On Wed, Jun 30, 2010 at 09:44:46AM -0700, Bruce Edge wrote:> On Wed, Jun 30, 2010 at 9:11 AM, Konrad Rzeszutek Wilk < > konrad.wilk@oracle.com> wrote: > > > On Tue, Jun 29, 2010 at 03:05:42PM -0700, Bruce Edge wrote: > > > I asked this a few weeks ago but didn''t get a response, so at the risk of > > > being a nag, I''ll abbreviate and restate. > > > > > > I know there are other Xen specific debuggers, but I want to know if > > there''s > > > any reason why SGI''s kdb, http://oss.sgi.com/projects/kdb, should not be > > > included in a dom0 pv-ops kernel? > > > > Upstream is integrating one that I think is in 2.6.33 > > or 2.6.34. So when we rev up that we will get it for free. > > > > Which upstream source is doing this integration? I''m not seeing any > reference to it on > > http://kernelnewbies.org/Linux_2_6_33 or > http://kernelnewbies.org/Linux_2_6_34I am getting them confused. Here is what I see: it dc7d552705215ac50a0617fcf51bb9c736255b8e Author: Jason Wessel <jason.wessel@windriver.com> Date: Thu Apr 17 20:05:37 2008 +0200 kgdb: core kgdb core code. Handles the protocol and the arch details. which looks to be in kernel/kgdb.c. You need to have CONFIG_KGDB enabled for it and some of the Linux command line paramters. That is not the SGI one but the other one. Is the KGDB not working (or you just are more comfortable with teh SGI one?)> > As in, can you use a null modem connection and poke Dom0 via that? > > > > Yep. The main connection to these boxes is the serial port. The kernel > cmdline has "console=hvc0,115200n8" so I get boot output on it, I''m using > "exec /sbin/getty -8 38400 hvc0" to get a login on the serial console, > which works fine. The 3xCtrl-A also works.I wonder if the problem you are hitting is that you are using the hvc0 driver. Not the real serial driver. Which means that the hvc0 driver isn''t picking up any of your input b/c its workqueue has been effectivly terminated. One way to go around this is to not use the serial console for Xen and have the Dom0 use it exclusivly. Which means you would be doing ''console=ttyS0,38400''. At least that is the theory - I am not sure if Xen will allow you to do that. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jan Beulich
2010-Jul-01 09:35 UTC
Re: [Xen-devel] Can I use SGI''s kdb with a dom0 pv-ops kernel?
>>> On 30.06.10 at 18:44, Bruce Edge <bruce.edge@gmail.com> wrote: >> Are you using the serial console also for Xen? > > > YesThat is your problem, I would assume, unless you taught kdb''s serial driver to use the Xen specific replacement (i.e. not going directly to the hardware serial port). Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel