Spapr capabilities are checked at machine init. If a capability cannot be used, an error message is printed and QEMU exits. In most places, the error message also contains an hint for the user. But we should use error_append_hint() for that, as explained in the "qapi/error.h" header.
This is already the case for cap_fwnmi_apply() and we now want to add a similar check for nested KVM-HV. Unfortunately, spapr_caps_apply() passes &error_fatal to all apply hooks and error_append_hint() is never called. So this reuses previous work from Vladimir Sementsov-Ogievskiy to address that. v3: - Add preliminary patch to use warn_report() instead of a convoluted error_setg()+warn_report_err() sequence v2: - Fix indentation and add some missing \n in patch 2 - Add ERRP_AUTO_PROPAGATE() to cap_nested_kvm_hv_apply() in patch 2 instead of patch 3 --- Greg Kurz (3): spapr: Simplify some warning printing paths in spapr_caps.c spapr: Use error_append_hint() in spapr_caps.c spapr: Forbid nested KVM-HV in pre-power9 compat mode Vladimir Sementsov-Ogievskiy (1): error: auto propagated local_err hw/ppc/spapr_caps.c | 127 ++++++++++++++++--------------- include/qapi/error.h | 205 ++++++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 239 insertions(+), 93 deletions(-) -- Greg