Re: [PATCH] ppc/pnv: fix default PHB4 QOM hierarchy

["Cédric Le Goater" <clg@kaod.org>]

On 2/18/22 21:28, Daniel Henrique Barboza wrote:
> Commit 3f4c369ea63e ("ppc/pnv: make PECs create and realize PHB4s")
> changed phb4_pec code to create the default PHB4 objects in
> pnv_pec_default_phb_realize(). In this process the stacks[] PEC array was
> removed and each PHB4 object is tied together with its PEC via the
> phb->pec pointer.
> 
> This change also broke the previous QOM hierarchy - the PHB4 objects are
> being created and not being parented to their respective chips. This can
> be verified by 'info pic' in a powernv9 domain with default settings.
> pnv_chip_power9_pic_print_info() will fail to find the PHBs because
> object_child_foreach_recursive() won't find any.
> 
> The solution is to set the parent chip and the parent bus, in the same
> way done for user created PHB4 devices, for all PHB4 devices.
> 
> Fixes: 3f4c369ea63e ("ppc/pnv: make PECs create and realize PHB4s")
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>


What about the pnv-phb3/4-root-port devices ? Should we attached
them also to the QOM hierarchy ?

Thanks,

C.

> ---
>   hw/pci-host/pnv_phb4.c | 36 ++++++++++++++++--------------------
>   1 file changed, 16 insertions(+), 20 deletions(-)
> 
> diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
> index e91249ef64..846e7d0c3e 100644
> --- a/hw/pci-host/pnv_phb4.c
> +++ b/hw/pci-host/pnv_phb4.c
> @@ -1568,40 +1568,36 @@ static PnvPhb4PecState *pnv_phb4_get_pec(PnvChip *chip, PnvPHB4 *phb,
>   static void pnv_phb4_realize(DeviceState *dev, Error **errp)
>   {
>       PnvPHB4 *phb = PNV_PHB4(dev);
> +    PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
> +    PnvChip *chip = pnv_get_chip(pnv, phb->chip_id);
>       PCIHostState *pci = PCI_HOST_BRIDGE(dev);
>       XiveSource *xsrc = &phb->xsrc;
> +    BusState *s;
>       Error *local_err = NULL;
>       int nr_irqs;
>       char name[32];
>   
> -    /* User created PHB */
> -    if (!phb->pec) {
> -        PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
> -        PnvChip *chip = pnv_get_chip(pnv, phb->chip_id);
> -        BusState *s;
> -
> -        if (!chip) {
> -            error_setg(errp, "invalid chip id: %d", phb->chip_id);
> -            return;
> -        }
> +    if (!chip) {
> +        error_setg(errp, "invalid chip id: %d", phb->chip_id);
> +        return;
> +    }
>   
> +    /* User created PHBs need to be assigned to a PEC */
> +    if (!phb->pec) {
>           phb->pec = pnv_phb4_get_pec(chip, phb, &local_err);
>           if (local_err) {
>               error_propagate(errp, local_err);
>               return;
>           }
> +    }
>   
> -        /*
> -         * Reparent user created devices to the chip to build
> -         * correctly the device tree.
> -         */
> -        pnv_chip_parent_fixup(chip, OBJECT(phb), phb->phb_id);
> +    /* Reparent the PHB to the chip to build the device tree */
> +    pnv_chip_parent_fixup(chip, OBJECT(phb), phb->phb_id);
>   
> -        s = qdev_get_parent_bus(DEVICE(chip));
> -        if (!qdev_set_parent_bus(DEVICE(phb), s, &local_err)) {
> -            error_propagate(errp, local_err);
> -            return;
> -        }
> +    s = qdev_get_parent_bus(DEVICE(chip));
> +    if (!qdev_set_parent_bus(DEVICE(phb), s, &local_err)) {
> +        error_propagate(errp, local_err);
> +        return;
>       }
>   
>       /* Set the "big_phb" flag */