From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Lalancette Subject: Re: [PATCH] Print a user-friendly message on failed vmentry Date: Thu, 20 May 2010 10:37:09 -0400 Message-ID: <4BF54915.7070201@redhat.com> References: <1274303782-21497-1-git-send-email-m.gamal005@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: avi@redhat.com, mtosatti@redhat.com, anthony@codemonkey.ws, kvm@vger.kernel.org To: Mohammed Gamal Return-path: Received: from mx1.redhat.com ([209.132.183.28]:41545 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751961Ab0ETOjU (ORCPT ); Thu, 20 May 2010 10:39:20 -0400 In-Reply-To: <1274303782-21497-1-git-send-email-m.gamal005@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: 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 > --- > 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. -- Chris Lalancette