Re: Unable to single-step in kvm, always results in a resume
Jan Kiszka wrote: Nicholas Amon wrote: So now I can step instruction but my breakpoints do not work. I have verified that disabling kvm restores the breakpoint functionality. Any suggestions? What kind of breakpoints, hardware-assisted or normal BPs? Are you trying to break into real-mode code (as stated below - BTW, top-postings should be avoided!) that happens to run on a non-brand-new Intel host? I never fully tested how well guest debugging works if KVM has to emulate instructions, and I wouldn't be surprised if there are "limitations". Jan Jan Kiszka wrote: Hi Nicholas, please don't drop CCs on reply. Nicholas Amon wrote: Hi Jan, Thanks for responding. Yes, I am able to step instruction when I disable kvm w/ the no-kvm option. My host kernel is 64bit 2.6.27 and the program that I am debugging is 32 bit but starts in real mode. But the KVM module I am running is from kvm-88. Is there anyway I can check the version definitively? kvm modules issue a message when being loaded, check your kernel log. qemu-kvm gives you the version via -version. OK, the problems you see is likely related to the very old versions you use. Update to recent kvm-kmod (2.6.32 series) and qemu-kvm (0.12 series) and retry. Jan Thanks, Nicholas Jan Kiszka wrote: Jan Kiszka wrote: Nicholas Amon wrote: Hi All, I am trying to single-step through my kernel using qemu and kvm. I have run qemu via: qemu-system-x86_64 -s -S -hda /home/nickamon/lab1/obj/kernel.img and also connected to the process using gdb. Problem is that whenever I try and step instruction, it seems to resume my kernel rather than allowing me to progress instruction by instruction. I have built the kvm snapshot from git and still no luck. Tried following the code for a few hours and have no luck. Any suggestions? What's you host kernel or kvm-kmod version? ...and does -no-kvm make any difference (except that it's much slower)? Jan My apologies for the late response. Normal breakpoints and yes I am breaking in real mode. This isn't a big issue for me since I am able to break when I disable kvm. So basically I disable kvm when I want to debug and enable it during normal execution. Thanks for all your help. Nick Nicholas Amon See How to Control & Track High-Risk Users: Join our Webinar on Tuesday, June 2 Network World Names Xceedium GateKeeper "RSA 2009 Best of Show" -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Unable to single-step in kvm, always results in a resume
So now I can step instruction but my breakpoints do not work. I have
verified that disabling kvm restores the breakpoint functionality. Any
suggestions?
Thanks,
Nicholas
Jan Kiszka wrote:
Hi Nicholas,
please don't drop CCs on reply.
Nicholas Amon wrote:
Hi Jan,
Thanks for responding. Yes, I am able to step instruction when I
disable kvm w/ the no-kvm option. My host kernel is 64bit 2.6.27 and
the program that I am debugging is 32 bit but starts in real mode. But
the KVM module I am running is from kvm-88. Is there anyway I can check
the version definitively?
kvm modules issue a message when being loaded, check your kernel log.
qemu-kvm gives you the version via -version.
OK, the problems you see is likely related to the very old versions you
use. Update to recent kvm-kmod (2.6.32 series) and qemu-kvm (0.12
series) and retry.
Jan
Thanks,
Nicholas
Jan Kiszka wrote:
Jan Kiszka wrote:
Nicholas Amon wrote:
Hi All,
I am trying to single-step through my kernel using qemu and kvm. I have
run qemu via: qemu-system-x86_64 -s -S -hda
/home/nickamon/lab1/obj/kernel.img and also connected to the process
using gdb.
Problem is that whenever I try and step instruction, it seems to resume
my kernel rather than allowing me to progress instruction by
instruction. I have built the kvm snapshot from git and still no luck.
Tried following the code for a few hours and have no luck. Any
suggestions?
What's you host kernel or kvm-kmod version?
...and does -no-kvm make any difference (except that it's much slower)?
Jan
--
Nicholas Amon
Senior Software Engineer
Xceedium Inc.
Office: 201-536-1000 x127
Cell: 732-236-7698
na...@xceedium.com
See How to Control & Track High-Risk Users: Join our Webinar on Tuesday,
June 2
Network World Names Xceedium GateKeeper "RSA 2009 Best of Show"
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Unable to single-step in kvm, always results in a resume
Thanks Jan. That fixed it.
Nicholas
Jan Kiszka wrote:
Hi Nicholas,
please don't drop CCs on reply.
Nicholas Amon wrote:
Hi Jan,
Thanks for responding. Yes, I am able to step instruction when I
disable kvm w/ the no-kvm option. My host kernel is 64bit 2.6.27 and
the program that I am debugging is 32 bit but starts in real mode. But
the KVM module I am running is from kvm-88. Is there anyway I can check
the version definitively?
kvm modules issue a message when being loaded, check your kernel log.
qemu-kvm gives you the version via -version.
OK, the problems you see is likely related to the very old versions you
use. Update to recent kvm-kmod (2.6.32 series) and qemu-kvm (0.12
series) and retry.
Jan
Thanks,
Nicholas
Jan Kiszka wrote:
Jan Kiszka wrote:
Nicholas Amon wrote:
Hi All,
I am trying to single-step through my kernel using qemu and kvm. I have
run qemu via: qemu-system-x86_64 -s -S -hda
/home/nickamon/lab1/obj/kernel.img and also connected to the process
using gdb.
Problem is that whenever I try and step instruction, it seems to resume
my kernel rather than allowing me to progress instruction by
instruction. I have built the kvm snapshot from git and still no luck.
Tried following the code for a few hours and have no luck. Any
suggestions?
What's you host kernel or kvm-kmod version?
...and does -no-kvm make any difference (except that it's much slower)?
Jan
--
Nicholas Amon
Senior Software Engineer
Xceedium Inc.
Office: 201-536-1000 x127
Cell: 732-236-7698
na...@xceedium.com
See How to Control & Track High-Risk Users: Join our Webinar on Tuesday,
June 2
Network World Names Xceedium GateKeeper "RSA 2009 Best of Show"
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Unable to single-step in kvm, always results in a resume
Hi All, I am trying to single-step through my kernel using qemu and kvm. I have run qemu via: qemu-system-x86_64 -s -S -hda /home/nickamon/lab1/obj/kernel.img and also connected to the process using gdb. Problem is that whenever I try and step instruction, it seems to resume my kernel rather than allowing me to progress instruction by instruction. I have built the kvm snapshot from git and still no luck. Tried following the code for a few hours and have no luck. Any suggestions? Thanks, Nicholas -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
