On Thu, May 20, 2010 at 5:37 PM, Chris Lalancette <clalance@xxxxxxxxxx> wrote: > On 05/19/2010 05:16 PM, Mohammed Gamal wrote: >> This patch address bug report in https://bugs.launchpad.net/qemu/+bug/530077. >> >> Failed vmentries were handled with handle_unhandled() which prints a rather >> unfriendly message to the user. This patch separates handling vmentry failures >> from unknown exit reasons and prints a friendly message to the user. >> >> Signed-off-by: Mohammed Gamal <m.gamal005@xxxxxxxxx> >> --- >> qemu-kvm.c | 16 +++++++++++++++- >> 1 files changed, 15 insertions(+), 1 deletions(-) >> >> diff --git a/qemu-kvm.c b/qemu-kvm.c >> index 35a4c8a..deb4df8 100644 >> --- a/qemu-kvm.c >> +++ b/qemu-kvm.c >> @@ -106,6 +106,20 @@ static int handle_unhandled(uint64_t reason) >> return -EINVAL; >> } >> >> +static int handle_failed_vmentry(uint64_t reason) >> +{ >> + fprintf(stderr, "kvm: vm entry failed with error 0x%" PRIx64 "\n\n", reason); >> + fprintf(stderr, "If you're runnning a guest on an Intel machine, it can be\n"); >> + fprintf(stderr, "most-likely due to the guest going into an invalid state\n"); >> + fprintf(stderr, "for Intel VT. For example, the guest maybe running in big\n"); >> + fprintf(stderr, "real mode which is not supported by Intel VT.\n\n"); >> + fprintf(stderr, "You may want to try enabling real mode emulation in KVM.\n"); >> + fprintf(stderr, "To Enable it, you may run the following commands as root:\n"); >> + fprintf(stderr, "# rmmod kvm_intel\n"); >> + fprintf(stderr, "# rmmod kvm\n"); >> + fprintf(stderr, "# modprobe kvm_intel emulate_invalid_guest_state=1\n"); >> + return -EINVAL; >> +} > > The thing is, there are other valid reasons for vmentry failure. A while ago I tracked > down a bug in the Linux kernel that was causing us to vmenter with invalid segments; > this message would have been very misleading in that case. I think you'd have to do > more complete analysis of the vmentry failure code to be more certain about the reason > for failure. > Your point is definitely valid, yet big real mode is usually the most likely case, and that's why this message is shown. Note also that it says it's _most likely_ a failure caused by an invalid guest state, but it doesn't rule out all other reasons. And in any case, it'd be better than just printing something along the lines of: " kvm: unhandled exit 80000021 kvm_run returned -22" > -- > Chris Lalancette > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
