pseries: Switch VGA endian on H_SET_MODE

When the guest switches the interrupt endian mode, which essentially
means a global machine endian switch, we want to change the VGA
framebuffer endian mode as well in order to be backward compatible
with existing guests who don't know about the new endian control
register.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

hw/ppc/spapr_hcall.c

@@ -731,12 +731,14 @@ static target_ulong h_set_mode_resource_le(PowerPCCPU *cpu,
         CPU_FOREACH(cs) {
             set_spr(cs, SPR_LPCR, 0, LPCR_ILE);
         }
+        spapr_pci_switch_vga(true);
         return H_SUCCESS;
 
     case H_SET_MODE_ENDIAN_LITTLE:
         CPU_FOREACH(cs) {
             set_spr(cs, SPR_LPCR, LPCR_ILE, LPCR_ILE);
         }
+        spapr_pci_switch_vga(false);
         return H_SUCCESS;
     }
 

hw/ppc/spapr_pci.c

@@ -982,3 +982,31 @@ static void spapr_pci_register_types(void)
 }
 
 type_init(spapr_pci_register_types)
+
+static int spapr_switch_one_vga(DeviceState *dev, void *opaque)
+{
+    bool be = *(bool *)opaque;
+
+    if (object_dynamic_cast(OBJECT(dev), "VGA")
+        || object_dynamic_cast(OBJECT(dev), "secondary-vga")) {
+        object_property_set_bool(OBJECT(dev), be, "big-endian-framebuffer",
+                                 &error_abort);
+    }
+    return 0;
+}
+
+void spapr_pci_switch_vga(bool big_endian)
+{
+    sPAPRPHBState *sphb;
+
+    /*
+     * For backward compatibility with existing guests, we switch
+     * the endianness of the VGA controller when changing the guest
+     * interrupt mode
+     */
+    QLIST_FOREACH(sphb, &spapr->phbs, list) {
+        BusState *bus = &PCI_HOST_BRIDGE(sphb)->bus->qbus;
+        qbus_walk_children(bus, spapr_switch_one_vga, NULL, NULL, NULL,
+                           &big_endian);
+    }
+}

include/hw/ppc/spapr.h

@@ -481,6 +481,7 @@ int spapr_dma_dt(void *fdt, int node_off, const char *propname,
                  uint32_t liobn, uint64_t window, uint32_t size);
 int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
                       sPAPRTCETable *tcet);
+void spapr_pci_switch_vga(bool big_endian);
 
 #define TYPE_SPAPR_RTC "spapr-rtc"