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[v2,3/3] board-qemu: add private hcall to inform host on "phandle" update

Message ID 149998472932.13629.5595173121521891953.stgit@bahia.lan
State Superseded
Headers show

Commit Message

Greg Kurz July 13, 2017, 10:25 p.m. UTC 
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@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
---
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(-)

Comments

Segher Boessenkool July 13, 2017, 11:10 p.m. UTC | #1 
On Fri, Jul 14, 2017 at 12:25:29AM +0200, Greg Kurz wrote:
> +\ Tell QEMU about the updated phandle:
> +: fdt-hv-update-phandle ( old new -- )
> +   hv-update-phandle ?dup 0 <> IF

0 <> IF   is the same as just   IF
(there also is   0<>   btw, for the cases where you actually need it).


Segher
diff mbox

Patch

diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs
index 1aeee3d93688..f274ffa072ac 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 0 <> IF
+      \ Ignore hcall not implemented error, print error otherwise
+      ?dup -2 <> IF ." HV-UPDATE-PHANDLE error: " . cr THEN
+   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__