Peter Maydell <peter.mayd...@linaro.org> writes:
> If the user forgot if=none on their drive specification they're likely
> to get an error message because the drive is assigned once automatically
> by QEMU and once by the manual id=/drive= user command line specification.
> Improve the error message produced in this case to explicitly guide the
> user towards if=none.
>
> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
> ---
> hw/core/qdev-properties-system.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/hw/core/qdev-properties-system.c
> b/hw/core/qdev-properties-system.c
> index 56954b4..bde9e12 100644
> --- a/hw/core/qdev-properties-system.c
> +++ b/hw/core/qdev-properties-system.c
> @@ -78,8 +78,20 @@ static void parse_drive(DeviceState *dev, const char *str,
> void **ptr,
> return;
> }
> if (blk_attach_dev(blk, dev) < 0) {
> - error_setg(errp, "Property '%s.%s' can't take value '%s', it's in
> use",
> - object_get_typename(OBJECT(dev)), propname, str);
> + DriveInfo *dinfo = blk_legacy_dinfo(blk);
> +
> + if (dinfo->auto_claimed) {
> + error_setg(errp, "Property '%s.%s' can't be set to drive ID
> '%s'; "
> + "that drive has been automatically connected to
> another "
> + "device. Use if=none if you do not want that
> automatic "
> + "connection.",
> + object_get_typename(OBJECT(dev)), propname, str);
> + } else {
> + error_setg(errp, "Property '%s.%s' can't be set to drive ID
> '%s'; "
> + "that drive has already been connected to another "
> + "device.",
> + object_get_typename(OBJECT(dev)), propname, str);
> + }
> return;
> }
> *ptr = blk;
We generally do not end error messages with a period.
The message for auto_claimed drives is of the form
LOCATION: This went wrong. Advice on how to fix it.
All in one awfully long line. A friendler format is
LOCATION: This went wrong
Advice on how to fix it.
Unfortunately, the Error API doesn't support that.
Easy with error_report():
error_report("This went wrong");
error_printf("Advice on how to fix it.");
With soon-to-be-gone qerror_report():
qerror_report(ERROR_CLASS_GENERIC_ERROR, "This went wrong");
error_printf_unless_qmp("Advice on how to fix it.");
I think we should just bite the bullet and extend Error to support
additional helpful information for humans. See also
http://lists.nongnu.org/archive/html/qemu-devel/2015-06/msg02482.html
and commit 7216ae3 "qemu-option: Disable two helpful messages that got
broken recently".
