Re: [PATCH v3] arm/aspeed: Rework NIC attachment

[Markus Armbruster]

Cédric Le Goater <address@hidden> writes:

> The number of MACs supported by an Aspeed SoC is defined by "macs_num"
> under the SoC model, that is two for the AST2400 and AST2500 and four
> for the AST2600. The model initializes the maximum number of supported
> MACs but the number of realized devices is capped by the number of
> network device back-ends defined on the command line. This can leave
> unrealized devices hanging around in the QOM composition tree.
>
> Modify the machine initialization to define which MACs are attached to
> a network device back-end using a bit-field property "macs-mask" and
> let the SoC realize all network devices.
>
> The default setting of "macs-mask" is "use MAC0" only, which works for
> all our AST2400 and AST2500 machines. The AST2600 machines have
> different configurations. The AST2600 EVB machine activates MAC1, MAC2
> and MAC3 and the Tacoma BMC machine activates MAC2.

Let's be more clear on what this means, and "This is actually a device
modelling fix for these two machines."  Okay?

> Inactive MACs will have no peer and QEMU may warn the user with :
>
>     qemu-system-arm: warning: nic ftgmac100.0 has no peer
>     qemu-system-arm: warning: nic ftgmac100.1 has no peer
>     qemu-system-arm: warning: nic ftgmac100.3 has no peer
>
> Signed-off-by: Cédric Le Goater <address@hidden>
> Reviewed-by: Markus Armbruster <address@hidden>

Here's the "info qom-tree" change for tacoma-bmc:

     /machine (tacoma-bmc-machine)
       /peripheral (container)
       /peripheral-anon (container)
       /soc (ast2600-a1)
         [...]
         /ftgmac100[0] (ftgmac100)
           /ftgmac100[0] (qemu:memory-region)
         /ftgmac100[1] (ftgmac100)
    +      /ftgmac100[0] (qemu:memory-region)
         /ftgmac100[2] (ftgmac100)
    +      /ftgmac100[0] (qemu:memory-region)
         /ftgmac100[3] (ftgmac100)
    +      /ftgmac100[0] (qemu:memory-region)
         [...]
         /mii[0] (aspeed-mmi)
           /aspeed-mmi[0] (qemu:memory-region)
         /mii[1] (aspeed-mmi)
    +      /aspeed-mmi[0] (qemu:memory-region)
         /mii[2] (aspeed-mmi)
    +      /aspeed-mmi[0] (qemu:memory-region)
         /mii[3] (aspeed-mmi)
    +      /aspeed-mmi[0] (qemu:memory-region)

These changes are due to realizing MAC1, MAC2, MAC3.  Looks good.

Here's "info qtree":

       dev: ftgmac100, id ""
         gpio-out "sysbus-irq" 1
         aspeed = true
    -    mac = "52:54:00:12:34:56"
    -    netdev = "hub0port0"
    +    mac = "52:54:00:12:34:57"
    +    netdev = ""
         mmio 000000001e660000/0000000000002000
       dev: ftgmac100, id ""
    -    aspeed = false
    -    mac = "00:00:00:00:00:00"
    +    gpio-out "sysbus-irq" 1
    +    aspeed = true
    +    mac = "52:54:00:12:34:58"
         netdev = ""
    +    mmio 000000001e680000/0000000000002000
       dev: ftgmac100, id ""
    -    aspeed = false
    -    mac = "00:00:00:00:00:00"
    -    netdev = ""
    +    gpio-out "sysbus-irq" 1
    +    aspeed = true
    +    mac = "52:54:00:12:34:56"
    +    netdev = "hub0port0"
    +    mmio 000000001e670000/0000000000002000
       dev: ftgmac100, id ""
    -    aspeed = false
    -    mac = "00:00:00:00:00:00"
    +    gpio-out "sysbus-irq" 1
    +    aspeed = true
    +    mac = "52:54:00:12:34:59"
         netdev = ""
    +    mmio 000000001e690000/0000000000002000
       [...]
       dev: aspeed-mmi, id ""
         mmio 000000001e650000/0000000000000008
       dev: aspeed-mmi, id ""
    +    mmio 000000001e650008/0000000000000008
       dev: aspeed-mmi, id ""
    +    mmio 000000001e650010/0000000000000008
       dev: aspeed-mmi, id ""
    +    mmio 000000001e650018/0000000000000008

Here we can see the network backend now gets connected to MAC2 instead
of MAC0.

This is without any networking-related options, i.e. we get just the
single default network backend.

> ---
>
>  To be applied on top of patch :
>
>  "arm/aspeed: Compute the number of CPUs from the SoC definition" 
>  http://patchwork.ozlabs.org/project/qemu-devel/patch/address@hidden/
>
>  Markus, do you mind taking this patch in your QOM series also ?

On the contrary!

I'll work my "info qom-tree" and "info qtree" diffs into the commit
message, if you don't mind.