[SLOF] [PATCH v3 3/3] board-qemu: add private hcall to inform host on "phandle" update

[Alexey Kardashevskiy]

On 15/07/17 22:06, Greg Kurz wrote:
> On Fri, 14 Jul 2017 08:54:42 +0200
> Greg Kurz <groug at kaod.org> wrote:
> 
>> The "interrupt-map" property in each PHB node references the "phandle"
>> property of the "interrupt-controller" node. This is used by the guest
>> OS to setup IRQs for any PCI device plugged into the PHB. QEMU sets this
>> property to an arbitrary value in the flattened DT passed to SLOF.
>>
>> Since commit 82954d4c1088, SLOF has some generic code to convert all
>> references to any "phandle" property to a SLOF specific value.
>>
>> This is is perfectly okay for coldplug devices, since the guest OS only
>> sees the converted value in "interrupt-map". It is a problem though for
>> hotplug devices. Since they don't go through SLOF, the guest OS receives
>> the arbitrary value set by QEMU and fails to setup IRQs.
>>
>> In order to support PHB hotplug, this patch introduces a new private
>> hcall, which allows SLOF to tell QEMU that a "phandle" was converted
>> from an old value to a new value.
>>
>> Suggested-by: Thomas Huth <thuth at redhat.com>
>> Signed-off-by: Greg Kurz <groug at kaod.org>
>> ---
>> v3: - drop "<> 0" before IF
>>
>> v2: - use ?dup
>>     - switch the order of the parameters of hv-update-phandle
>>     - added stack comment to hv-update-phandle
>> ---
>>  board-qemu/slof/fdt.fs    |   14 ++++++++++++--
>>  lib/libhvcall/hvcall.code |    7 +++++++
>>  lib/libhvcall/hvcall.in   |    1 +
>>  lib/libhvcall/libhvcall.h |    1 +
>>  4 files changed, 21 insertions(+), 2 deletions(-)
>>
>> diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs
>> index 851645eae299..a78e8ff208f6 100644
>> --- a/board-qemu/slof/fdt.fs
>> +++ b/board-qemu/slof/fdt.fs
>> @@ -308,18 +308,28 @@ fdt-claim-reserve
>>     3drop
>>  ;
>>  
>> +\ Tell QEMU about the updated phandle:
>> +: fdt-hv-update-phandle ( old new -- )
>> +   hv-update-phandle ?dup IF
>> +      \ Ignore hcall not implemented error, print error otherwise
>> +      ?dup -2 <> IF ." HV-UPDATE-PHANDLE error: " . cr THEN
>           ^^
> This is wrong... :-\
> 
> fdt-hv-update-phandle doesn't return anything: we shouldn't ?dup the return
> value (which we know to be non-null because of the previous ?dup BTW).

Does this mean you are reposting it soon?
For now, I've picked 1/3 and 2/3 so no need to repost, thanks.


> 
>> +   THEN
>> +;
>> +
>>  \ Replace one FDT phandle "val" with a OF1275 phandle "node" in the
>>  \ whole tree:
>>  : fdt-update-phandle ( val node -- )
>>     >r  
>>     FALSE TO (fdt-phandle-replaced)
>> -   r@ s" /" find-node               ( val node root )
>> -   fdt-replace-all-phandles
>> +   r@ 2dup s" /" find-node          ( val node val node root )
>> +   fdt-replace-all-phandles         ( val node )
>>     (fdt-phandle-replaced) IF
>> +      fdt-hv-update-phandle
>>        r@ set-node
>>        s" phandle" delete-property
>>        s" linux,phandle" delete-property
>>     ELSE
>> +      2drop
>>        diagnostic-mode? IF
>>           cr ." Warning: Did not replace phandle in " r@ node>path type cr
>>        THEN
>> diff --git a/lib/libhvcall/hvcall.code b/lib/libhvcall/hvcall.code
>> index 0ff50f27e8a9..834974862ef5 100644
>> --- a/lib/libhvcall/hvcall.code
>> +++ b/lib/libhvcall/hvcall.code
>> @@ -129,3 +129,10 @@ PRIM(check_X2d_and_X2d_patch_X2d_sc1)
>>  
>>  	patch_broken_sc1((void*)start, (void*)end, (void*)patch_ins);
>>  MIRP
>> +
>> +// : hv-update-phandle ( old_phandle new_phandle -- res )
>> +PRIM(hv_X2d_update_X2d_phandle)
>> +	uint32_t new_phandle = TOS.u; POP;
>> +	uint32_t old_phandle = TOS.u;
>> +	TOS.u = hv_generic(KVMPPC_H_UPDATE_PHANDLE, old_phandle, new_phandle);
>> +MIRP
>> diff --git a/lib/libhvcall/hvcall.in b/lib/libhvcall/hvcall.in
>> index 4437b77f001d..ab7513af8977 100644
>> --- a/lib/libhvcall/hvcall.in
>> +++ b/lib/libhvcall/hvcall.in
>> @@ -31,4 +31,5 @@ cod(RX!)
>>  cod(hv-logical-memop)
>>  cod(hv-cas)
>>  cod(hv-rtas-update)
>> +cod(hv-update-phandle)
>>  cod(get-print-version)
>> diff --git a/lib/libhvcall/libhvcall.h b/lib/libhvcall/libhvcall.h
>> index b2ea3f6bf944..5776a2b772f7 100644
>> --- a/lib/libhvcall/libhvcall.h
>> +++ b/lib/libhvcall/libhvcall.h
>> @@ -25,6 +25,7 @@
>>  /* Client Architecture support */
>>  #define KVMPPC_H_CAS            (KVMPPC_HCALL_BASE + 0x2)
>>  #define KVMPPC_H_RTAS_UPDATE    (KVMPPC_HCALL_BASE + 0x3)
>> +#define KVMPPC_H_UPDATE_PHANDLE (KVMPPC_HCALL_BASE + 0x4)
>>  
>>  #ifndef __ASSEMBLY__
>>  
>>
>> _______________________________________________
>> SLOF mailing list
>> SLOF at lists.ozlabs.org
>> https://lists.ozlabs.org/listinfo/slof
> 
> 
> 
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> 


-- 
Alexey

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