* kvm guest debug using gdb on x86 @ 2009-05-19 18:53 Aneesh Kumar K.V 2009-05-19 19:10 ` Aneesh Kumar K.V 0 siblings, 1 reply; 10+ messages in thread From: Aneesh Kumar K.V @ 2009-05-19 18:53 UTC (permalink / raw) To: kvm, jan.kiszka Hi, With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get the guest debugging with gdb. I get the following error. $gdb ./vmlinux GNU gdb 6.8-debian Copyright (C) 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i486-linux-gnu"... (gdb) b do_fork Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. (gdb) target remote localhost:1234 Remote debugging using localhost:1234 [New Thread 1] Remote 'g' packet reply is too long: 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 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 (gdb) any patches that i can try ? -aneesh ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-19 18:53 kvm guest debug using gdb on x86 Aneesh Kumar K.V @ 2009-05-19 19:10 ` Aneesh Kumar K.V 2009-05-20 8:10 ` Jan Kiszka 0 siblings, 1 reply; 10+ messages in thread From: Aneesh Kumar K.V @ 2009-05-19 19:10 UTC (permalink / raw) To: kvm, jan.kiszka On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: > Hi, > > With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get > the guest debugging with gdb. I get the following error. > > $gdb ./vmlinux > GNU gdb 6.8-debian > Copyright (C) 2008 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show > copying" > and "show warranty" for details. > This GDB was configured as "i486-linux-gnu"... > (gdb) b do_fork > Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. > (gdb) target remote localhost:1234 > Remote debugging using localhost:1234 > [New Thread 1] > Remote 'g' packet reply is too long: > 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 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > (gdb) > > any patches that i can try ? Works better with the four patches found at http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb But a next and continue doesn't get the prompt back on gdb. The guest does stops the execution. -aneesh ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-19 19:10 ` Aneesh Kumar K.V @ 2009-05-20 8:10 ` Jan Kiszka 2009-05-20 8:40 ` Aneesh Kumar K.V 0 siblings, 1 reply; 10+ messages in thread From: Jan Kiszka @ 2009-05-20 8:10 UTC (permalink / raw) To: Aneesh Kumar K.V; +Cc: kvm Aneesh Kumar K.V wrote: > On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: >> Hi, >> >> With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get >> the guest debugging with gdb. I get the following error. >> >> $gdb ./vmlinux >> GNU gdb 6.8-debian >> Copyright (C) 2008 Free Software Foundation, Inc. >> License GPLv3+: GNU GPL version 3 or later >> <http://gnu.org/licenses/gpl.html> >> This is free software: you are free to change and redistribute it. >> There is NO WARRANTY, to the extent permitted by law. Type "show >> copying" >> and "show warranty" for details. >> This GDB was configured as "i486-linux-gnu"... >> (gdb) b do_fork >> Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. >> (gdb) target remote localhost:1234 >> Remote debugging using localhost:1234 >> [New Thread 1] >> Remote 'g' packet reply is too long: >> 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 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >> (gdb) >> >> any patches that i can try ? > > Works better with the four patches found at > > http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb > > But a next and continue doesn't get the prompt back on gdb. The guest > does stops the execution. What arch is host and guest (x86-32 or -64)? What KVM versions are you using? Are you sure that guest and vmlinux matches? Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 8:10 ` Jan Kiszka @ 2009-05-20 8:40 ` Aneesh Kumar K.V 2009-05-20 8:57 ` Jan Kiszka 0 siblings, 1 reply; 10+ messages in thread From: Aneesh Kumar K.V @ 2009-05-20 8:40 UTC (permalink / raw) To: Jan Kiszka; +Cc: kvm On Wed, May 20, 2009 at 10:10:59AM +0200, Jan Kiszka wrote: > Aneesh Kumar K.V wrote: > > On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: > >> Hi, > >> > >> With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get > >> the guest debugging with gdb. I get the following error. > >> > >> $gdb ./vmlinux > >> GNU gdb 6.8-debian > >> Copyright (C) 2008 Free Software Foundation, Inc. > >> License GPLv3+: GNU GPL version 3 or later > >> <http://gnu.org/licenses/gpl.html> > >> This is free software: you are free to change and redistribute it. > >> There is NO WARRANTY, to the extent permitted by law. Type "show > >> copying" > >> and "show warranty" for details. > >> This GDB was configured as "i486-linux-gnu"... > >> (gdb) b do_fork > >> Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. > >> (gdb) target remote localhost:1234 > >> Remote debugging using localhost:1234 > >> [New Thread 1] > >> Remote 'g' packet reply is too long: > >> 7fa5000000000000000000000000000057e209c10000000004000000000000000000000000000000c8b3d0c100000000c03fd1c100000000a83fd1c10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000912d03c1000000000202000060000000680000007b0000007b000000d8000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000f60b801540000000000000000000007f03000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > >> (gdb) > >> > >> any patches that i can try ? > > > > Works better with the four patches found at > > > > http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb > > > > But a next and continue doesn't get the prompt back on gdb. The guest > > does stops the execution. > > What arch is host and guest (x86-32 or -64)? What KVM versions are you > using? Are you sure that guest and vmlinux matches? > Both host and guest are x86-32. For kvm user space I did a git clone from git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git. I tested with commit 22d239bcee126742df46938ee8ddc7c6b9209e23. That version fails with the "remote g packet reply is too long" error. Then i applied the four patches from your git repo. That gets the guest to stop execution on breakpoint, i can check the stack. but single stepping doesn't work. Guest kernel I tried was linux-2.6-tip -aneesh ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 8:40 ` Aneesh Kumar K.V @ 2009-05-20 8:57 ` Jan Kiszka 2009-05-20 9:04 ` Aneesh Kumar K.V 0 siblings, 1 reply; 10+ messages in thread From: Jan Kiszka @ 2009-05-20 8:57 UTC (permalink / raw) To: Aneesh Kumar K.V; +Cc: kvm Aneesh Kumar K.V wrote: > On Wed, May 20, 2009 at 10:10:59AM +0200, Jan Kiszka wrote: >> Aneesh Kumar K.V wrote: >>> On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: >>>> Hi, >>>> >>>> With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get >>>> the guest debugging with gdb. I get the following error. >>>> >>>> $gdb ./vmlinux >>>> GNU gdb 6.8-debian >>>> Copyright (C) 2008 Free Software Foundation, Inc. >>>> License GPLv3+: GNU GPL version 3 or later >>>> <http://gnu.org/licenses/gpl.html> >>>> This is free software: you are free to change and redistribute it. >>>> There is NO WARRANTY, to the extent permitted by law. Type "show >>>> copying" >>>> and "show warranty" for details. >>>> This GDB was configured as "i486-linux-gnu"... >>>> (gdb) b do_fork >>>> Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. >>>> (gdb) target remote localhost:1234 >>>> Remote debugging using localhost:1234 >>>> [New Thread 1] >>>> Remote 'g' packet reply is too long: >>>> 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 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00 >> 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >>>> (gdb) >>>> >>>> any patches that i can try ? >>> Works better with the four patches found at >>> >>> http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb >>> >>> But a next and continue doesn't get the prompt back on gdb. The guest >>> does stops the execution. >> What arch is host and guest (x86-32 or -64)? What KVM versions are you >> using? Are you sure that guest and vmlinux matches? >> > > Both host and guest are x86-32. For kvm user space I did a git clone > from git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git. I tested with > commit 22d239bcee126742df46938ee8ddc7c6b9209e23. That version fails > with the "remote g packet reply is too long" error. Then i applied the > four patches from your git repo. That gets the guest to stop execution > on breakpoint, i can check the stack. but single stepping doesn't work. > > Guest kernel I tried was linux-2.6-tip Does debugging work with -no-kvm, ie. in TCG mode? Jan PS: For qemu-kvm.git you can now use my qemu gdb queue directly, ie. you don't need to rebase manually. -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 8:57 ` Jan Kiszka @ 2009-05-20 9:04 ` Aneesh Kumar K.V 2009-05-20 9:41 ` Jan Kiszka 0 siblings, 1 reply; 10+ messages in thread From: Aneesh Kumar K.V @ 2009-05-20 9:04 UTC (permalink / raw) To: Jan Kiszka; +Cc: kvm On Wed, May 20, 2009 at 10:57:21AM +0200, Jan Kiszka wrote: > Aneesh Kumar K.V wrote: > > On Wed, May 20, 2009 at 10:10:59AM +0200, Jan Kiszka wrote: > >> Aneesh Kumar K.V wrote: > >>> On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: > >>>> Hi, > >>>> > >>>> With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get > >>>> the guest debugging with gdb. I get the following error. > >>>> > >>>> $gdb ./vmlinux > >>>> GNU gdb 6.8-debian > >>>> Copyright (C) 2008 Free Software Foundation, Inc. > >>>> License GPLv3+: GNU GPL version 3 or later > >>>> <http://gnu.org/licenses/gpl.html> > >>>> This is free software: you are free to change and redistribute it. > >>>> There is NO WARRANTY, to the extent permitted by law. Type "show > >>>> copying" > >>>> and "show warranty" for details. > >>>> This GDB was configured as "i486-linux-gnu"... > >>>> (gdb) b do_fork > >>>> Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. > >>>> (gdb) target remote localhost:1234 > >>>> Remote debugging using localhost:1234 > >>>> [New Thread 1] > >>>> Remote 'g' packet reply is too long: > >>>> 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 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > 00 > >> 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > >>>> (gdb) > >>>> > >>>> any patches that i can try ? > >>> Works better with the four patches found at > >>> > >>> http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb > >>> > >>> But a next and continue doesn't get the prompt back on gdb. The guest > >>> does stops the execution. > >> What arch is host and guest (x86-32 or -64)? What KVM versions are you > >> using? Are you sure that guest and vmlinux matches? > >> > > > > Both host and guest are x86-32. For kvm user space I did a git clone > > from git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git. I tested with > > commit 22d239bcee126742df46938ee8ddc7c6b9209e23. That version fails > > with the "remote g packet reply is too long" error. Then i applied the > > four patches from your git repo. That gets the guest to stop execution > > on breakpoint, i can check the stack. but single stepping doesn't work. > > > > Guest kernel I tried was linux-2.6-tip > > Does debugging work with -no-kvm, ie. in TCG mode? Yes. debugging works with -no-kvm option. I can do single stepping. -aneesh ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 9:04 ` Aneesh Kumar K.V @ 2009-05-20 9:41 ` Jan Kiszka 2009-05-20 9:46 ` Jan Kiszka 0 siblings, 1 reply; 10+ messages in thread From: Jan Kiszka @ 2009-05-20 9:41 UTC (permalink / raw) To: Aneesh Kumar K.V; +Cc: kvm Aneesh Kumar K.V wrote: > On Wed, May 20, 2009 at 10:57:21AM +0200, Jan Kiszka wrote: >> Aneesh Kumar K.V wrote: >>> On Wed, May 20, 2009 at 10:10:59AM +0200, Jan Kiszka wrote: >>>> Aneesh Kumar K.V wrote: >>>>> On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: >>>>>> Hi, >>>>>> >>>>>> With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get >>>>>> the guest debugging with gdb. I get the following error. >>>>>> >>>>>> $gdb ./vmlinux >>>>>> GNU gdb 6.8-debian >>>>>> Copyright (C) 2008 Free Software Foundation, Inc. >>>>>> License GPLv3+: GNU GPL version 3 or later >>>>>> <http://gnu.org/licenses/gpl.html> >>>>>> This is free software: you are free to change and redistribute it. >>>>>> There is NO WARRANTY, to the extent permitted by law. Type "show >>>>>> copying" >>>>>> and "show warranty" for details. >>>>>> This GDB was configured as "i486-linux-gnu"... >>>>>> (gdb) b do_fork >>>>>> Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. >>>>>> (gdb) target remote localhost:1234 >>>>>> Remote debugging using localhost:1234 >>>>>> [New Thread 1] >>>>>> Remote 'g' packet reply is too long: >>>>>> 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 > 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >> 00 >>>> 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >>>>>> (gdb) >>>>>> >>>>>> any patches that i can try ? >>>>> Works better with the four patches found at >>>>> >>>>> http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb >>>>> >>>>> But a next and continue doesn't get the prompt back on gdb. The guest >>>>> does stops the execution. >>>> What arch is host and guest (x86-32 or -64)? What KVM versions are you >>>> using? Are you sure that guest and vmlinux matches? >>>> >>> Both host and guest are x86-32. For kvm user space I did a git clone >>> from git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git. I tested with >>> commit 22d239bcee126742df46938ee8ddc7c6b9209e23. That version fails >>> with the "remote g packet reply is too long" error. Then i applied the >>> four patches from your git repo. That gets the guest to stop execution >>> on breakpoint, i can check the stack. but single stepping doesn't work. >>> >>> Guest kernel I tried was linux-2.6-tip >> Does debugging work with -no-kvm, ie. in TCG mode? > > > Yes. debugging works with -no-kvm option. I can do single stepping. > Sigh, confirmed, there is a regression in qemu-kvm. Will dig into this. Older kvm-userspace should be fine (e.g. the last version you can pull from my tree). Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 9:41 ` Jan Kiszka @ 2009-05-20 9:46 ` Jan Kiszka 2009-05-20 10:49 ` Avi Kivity 0 siblings, 1 reply; 10+ messages in thread From: Jan Kiszka @ 2009-05-20 9:46 UTC (permalink / raw) To: Aneesh Kumar K.V; +Cc: kvm Jan Kiszka wrote: > Aneesh Kumar K.V wrote: >> On Wed, May 20, 2009 at 10:57:21AM +0200, Jan Kiszka wrote: >>> Aneesh Kumar K.V wrote: >>>> On Wed, May 20, 2009 at 10:10:59AM +0200, Jan Kiszka wrote: >>>>> Aneesh Kumar K.V wrote: >>>>>> On Wed, May 20, 2009 at 12:23:12AM +0530, Aneesh Kumar K.V wrote: >>>>>>> Hi, >>>>>>> >>>>>>> With the latest qemu-kvm and 2.6.30-rc6 kernel i am not able to get >>>>>>> the guest debugging with gdb. I get the following error. >>>>>>> >>>>>>> $gdb ./vmlinux >>>>>>> GNU gdb 6.8-debian >>>>>>> Copyright (C) 2008 Free Software Foundation, Inc. >>>>>>> License GPLv3+: GNU GPL version 3 or later >>>>>>> <http://gnu.org/licenses/gpl.html> >>>>>>> This is free software: you are free to change and redistribute it. >>>>>>> There is NO WARRANTY, to the extent permitted by law. Type "show >>>>>>> copying" >>>>>>> and "show warranty" for details. >>>>>>> This GDB was configured as "i486-linux-gnu"... >>>>>>> (gdb) b do_fork >>>>>>> Breakpoint 1 at 0xc106cfc8: file kernel/fork.c, line 1347. >>>>>>> (gdb) target remote localhost:1234 >>>>>>> Remote debugging using localhost:1234 >>>>>>> [New Thread 1] >>>>>>> Remote 'g' packet reply is too long: >>>>>>> 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 0 >> 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >>> 00 >>>>> 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >>>>>>> (gdb) >>>>>>> >>>>>>> any patches that i can try ? >>>>>> Works better with the four patches found at >>>>>> >>>>>> http://git.kiszka.org/?p=kvm-userspace.git;a=shortlog;h=refs/heads/queues/gdb >>>>>> >>>>>> But a next and continue doesn't get the prompt back on gdb. The guest >>>>>> does stops the execution. >>>>> What arch is host and guest (x86-32 or -64)? What KVM versions are you >>>>> using? Are you sure that guest and vmlinux matches? >>>>> >>>> Both host and guest are x86-32. For kvm user space I did a git clone >>>> from git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git. I tested with >>>> commit 22d239bcee126742df46938ee8ddc7c6b9209e23. That version fails >>>> with the "remote g packet reply is too long" error. Then i applied the >>>> four patches from your git repo. That gets the guest to stop execution >>>> on breakpoint, i can check the stack. but single stepping doesn't work. >>>> >>>> Guest kernel I tried was linux-2.6-tip >>> Does debugging work with -no-kvm, ie. in TCG mode? >> >> Yes. debugging works with -no-kvm option. I can do single stepping. >> > > Sigh, confirmed, there is a regression in qemu-kvm. Will dig into this. Hmpf, the regression is also present in qemu upstream in kvm mode. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 9:46 ` Jan Kiszka @ 2009-05-20 10:49 ` Avi Kivity 2009-05-21 7:54 ` Jan Kiszka 0 siblings, 1 reply; 10+ messages in thread From: Avi Kivity @ 2009-05-20 10:49 UTC (permalink / raw) To: Jan Kiszka; +Cc: Aneesh Kumar K.V, kvm Jan Kiszka wrote: >> Sigh, confirmed, there is a regression in qemu-kvm. Will dig into this. >> > > Hmpf, the regression is also present in qemu upstream in kvm mode. > We need gdb tests in kvm-autotest. -- error compiling committee.c: too many arguments to function ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: kvm guest debug using gdb on x86 2009-05-20 10:49 ` Avi Kivity @ 2009-05-21 7:54 ` Jan Kiszka 0 siblings, 0 replies; 10+ messages in thread From: Jan Kiszka @ 2009-05-21 7:54 UTC (permalink / raw) To: Avi Kivity; +Cc: Aneesh Kumar K.V, kvm [-- Attachment #1: Type: text/plain, Size: 410 bytes --] Avi Kivity wrote: > Jan Kiszka wrote: >>> Sigh, confirmed, there is a regression in qemu-kvm. Will dig into this. >>> >> >> Hmpf, the regression is also present in qemu upstream in kvm mode. That was only local confusion, the regression turned out to be qemu-kvm-only. > > We need gdb tests in kvm-autotest. > Yes, I know. It just takes a bit free resources to set this up... Jan [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 257 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2009-05-21 7:54 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2009-05-19 18:53 kvm guest debug using gdb on x86 Aneesh Kumar K.V 2009-05-19 19:10 ` Aneesh Kumar K.V 2009-05-20 8:10 ` Jan Kiszka 2009-05-20 8:40 ` Aneesh Kumar K.V 2009-05-20 8:57 ` Jan Kiszka 2009-05-20 9:04 ` Aneesh Kumar K.V 2009-05-20 9:41 ` Jan Kiszka 2009-05-20 9:46 ` Jan Kiszka 2009-05-20 10:49 ` Avi Kivity 2009-05-21 7:54 ` Jan Kiszka
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