On Thu, 28 Jan 2021 08:46:01 +0100 Cédric Le Goater <c...@kaod.org> wrote:
> On 1/28/21 1:46 AM, Joel Stanley wrote: > > On Tue, 26 Jan 2021 at 17:14, Cédric Le Goater <c...@kaod.org> wrote: > >> > >> and reuse pnv_bmc_set_pnor() to share the setting of the PNOR. > >> > >> Signed-off-by: Cédric Le Goater <c...@kaod.org> > >> --- > >> hw/ppc/pnv_bmc.c | 7 +------ > >> 1 file changed, 1 insertion(+), 6 deletions(-) > >> > >> diff --git a/hw/ppc/pnv_bmc.c b/hw/ppc/pnv_bmc.c > >> index 67ebb16c4d5f..86d16b493539 100644 > >> --- a/hw/ppc/pnv_bmc.c > >> +++ b/hw/ppc/pnv_bmc.c > >> @@ -260,13 +260,8 @@ IPMIBmc *pnv_bmc_create(PnvPnor *pnor) > >> Object *obj; > >> > >> obj = object_new(TYPE_IPMI_BMC_SIMULATOR); > >> - object_ref(OBJECT(pnor)); > >> - object_property_add_const_link(obj, "pnor", OBJECT(pnor)); > > > > I assume it's ok to move the link set to after the realise of the BMC > > object? > > > When 2 objects need to be linked, one has to be realized first. Realize isn't a QOM concept in the first place... > I suppose this is why it is allowed but I am not expert in that area. > ... so no surprise object_property_add_const_link() doesn't care about it. > Greg ? > What is important though is that a property with a given name can only be added *once* to an object during its lifetime. Doing the contrary is a bug and QEMU aborts. So, with this in mind, it seems to me that adding QOM properties to a device object should only be done from some init path that is only called once. > That was the case already when defining a "ipmi-bmc-sim" device on the > command line. > Yeah and the property is added during machine reset... which is typically a path that can be taken several times during the machine lifetime. The potential crash is avoided because pnv_reset() doesn't call pnv_bmc_set_pnor() if pnv->bmc is already set, but this is a fragile workaround... A QOM link doesn't look like the correct way to model the BMC accesses to the PNOR. Since the only user is hiomap_cmd(), it seems you could reach the same result with a pointer to the PNOR object being passed to ipmi_sim_register_netfn() and later passed to hiomap_cmd(). > C. > > > >> qdev_realize(DEVICE(obj), NULL, &error_fatal); > >> - > >> - /* Install the HIOMAP protocol handlers to access the PNOR */ > >> - ipmi_sim_register_netfn(IPMI_BMC_SIMULATOR(obj), IPMI_NETFN_OEM, > >> - &hiomap_netfn); > >> + pnv_bmc_set_pnor(IPMI_BMC(obj), pnor); > >> > >> return IPMI_BMC(obj); > >> } > >> -- > >> 2.26.2 > >> > >> >
