Messages in this thread | | | Subject | Re: kvm causing memory corruption? now 2.6.26-rc4 | From | Dave Hansen <> | Date | Mon, 02 Jun 2008 15:30:10 -0700 |
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On Thu, 2008-03-27 at 16:59 +0200, Avi Kivity wrote: > Dave Hansen wrote: > > On Thu, 2008-03-27 at 12:10 +0200, Avi Kivity wrote: > >> btw, is this with >= 4GB RAM on the host? > > > > Well, are you asking whether I have PAE on or not? :) > > No, I'm asking whether there is a possibility of address truncation :) > > PAE by itself doesn't affect kvm much, as it always runs the guest in > pae mode. > > Can you try running with mem=2000M or something?
I have a few more data points on this. Sorry for the massive delay from the last report -- I'm being a crappy bug reporter. But, this is on my one and only laptop which makes it a serious pain to diagnose. I also didn't have a hardware serial console on it before, which I do now. This is all on 2.6.26-rc4-01549-g1beee8d.
Adding the mem= does not help at all. But, it is all a bit more diagnosable now than a month or two ago. I turned on all of the kernel debugging that I could get my grubby little hands on. It now oopses quite consistently when kvm runs instead of after. Here's a collection of oopses that I captured after setting up a serial line:
http://sr71.net/~dave/kvm-oops1.txt
After collecting all those, I turned on CONFIG_DEBUG_HIGHMEM and the oopses miraculously stopped. But, the guest hung (for at least 5 minutes or so) during windows bootup, pegging my host CPU. Most of the CPU was going to klogd, so I checked dmesg.
I was seeing messages like this
[ 428.918108] kvm_handle_exit: unexpected, valid vectoring info and exit reason is 0x9
And quite a few of them, like 100,000/sec. That's why klogd was pegging the CPU. Any idea on a next debugging step?
-- Dave
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