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

[Greg Kurz]

On Mon, 17 Jul 2017 13:40:56 +1000
Alexey Kardashevskiy <aik at ozlabs.ru> wrote:

> 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?

I was on vacation last week but, yes, I plan to repost very soon.

> For now, I've picked 1/3 and 2/3 so no need to repost, thanks.
> 

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  
> > 
> > 
> > 
> > _______________________________________________
> > SLOF mailing list
> > SLOF at lists.ozlabs.org
> > https://lists.ozlabs.org/listinfo/slof
> >   
> 
> 

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