Re: [PATCH] Print a user-friendly message on failed vmentry

[Ryan Harper <ryanh@us.ibm.com>]

* Mohammed Gamal <m.gamal005@gmail.com> [2010-05-19 16:17]:
> 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@gmail.com>
> ---
>  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");

We might want to qualify this with certain cpu versions.  IIRC, the VMX
unrestricted mode should handle big real mode correctly, no?   Maybe, 

+    fprintf(stderr, "on some Intel processors. For example, the guest maybe running in big\n");
+    fprintf(stderr, "real mode which is not supported on most Intel processors.\n\n");

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com