Re: [PATCH 00/33] hw/cpu/arm: Remove one use of qemu_get_cpu() in A7/A15 MPCore priv

[Philippe Mathieu-Daudé]

+Peter/Fabiano

On 2/1/24 17:41, Cédric Le Goater wrote:
> On 1/2/24 17:15, Philippe Mathieu-Daudé wrote:
> > Hi Cédric,
> >
> > On 2/1/24 15:55, Cédric Le Goater wrote:
> > > On 12/12/23 17:29, Philippe Mathieu-Daudé wrote:
> > > > Hi,
> > > >
> > > > When a MPCore cluster is used, the Cortex-A cores belong the the
> > > > cluster container, not to the board/soc layer. This series move
> > > > the creation of vCPUs to the MPCore private container.
> > > >
> > > > Doing so we consolidate the QOM model, moving common code in a
> > > > central place (abstract MPCore parent).
> > >
> > > Changing the QOM hierarchy has an impact on the state of the machine
> > > and some fixups are then required to maintain migration compatibility.
> > > This can become a real headache for KVM machines like virt for which
> > > migration compatibility is a feature, less for emulated ones.
> >
> > All changes are either moving properties (which are not migrated)
> > or moving non-migrated QOM members (i.e. pointers of ARMCPU, which
> > is still migrated elsewhere). So I don't see any obvious migration
> > problem, but I might be missing something, so I Cc'ed Juan :>
> We broke migration compatibility by moving the IC object in the QOM
> hierarchy of the pseries machines in the past. These changes might
> be different. Here is the QOM tree of the ast2600 SoC.
>
> before :
>
>    /soc (ast2600-a3)
>      /a7mpcore (a15mpcore_priv)
>        /a15mp-priv-container[0] (memory-region)
>        /gic (arm_gic)
>          /gic_cpu[0] (memory-region)
>          /gic_cpu[1] (memory-region)
>          /gic_cpu[2] (memory-region)
>          /gic_dist[0] (memory-region)
>          /gic_vcpu[0] (memory-region)
>          /gic_viface[0] (memory-region)
>          /gic_viface[1] (memory-region)
>          /gic_viface[2] (memory-region)
>      /cpu[0] (cortex-a7-arm-cpu)
>      /cpu[1] (cortex-a7-arm-cpu)
>
> after :
>
>    /soc (ast2600-a3)
>      /a7mpcore (a7mpcore_priv)
>        /cpu[0] (cortex-a7-arm-cpu)
>        /cpu[1] (cortex-a7-arm-cpu)
>        /gic (arm_gic)
>          /gic_cpu[0] (memory-region)
>          /gic_cpu[1] (memory-region)
>          /gic_cpu[2] (memory-region)
>          /gic_dist[0] (memory-region)
>        /mpcore-priv-container[0] (memory-region)
>
>
> Thanks,
>
> C.