Power Hypervisor code requires access to the SECURITY_SWITCH
XSCOM register at MMIO address 0x80028 (scom address 0x10005).
Adding basic read support for now so that is doesn't cause
error messages to be posted.

Reviewed-by: Chalapathi V <chalapathi.v@linux.ibm.com>
Reviewed-by: Glenn Miles <milesg@linux.ibm.com>
Reviewed-by: Aditya Gupta <adityag@linux.ibm.com>
Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
Signed-off-by: Caleb Schlossin <calebs@linux.ibm.com>
---
 hw/ppc/pnv_xscom.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/ppc/pnv_xscom.c b/hw/ppc/pnv_xscom.c
index 8557b560ae..dc1ffc6c01 100644
--- a/hw/ppc/pnv_xscom.c
+++ b/hw/ppc/pnv_xscom.c
@@ -61,6 +61,8 @@ static uint32_t pnv_xscom_pcba(PnvChip *chip, uint64_t addr)
 static uint64_t xscom_read_default(PnvChip *chip, uint32_t pcba)
 {
     switch (pcba) {
+    case 0x10005:       /* SECURITY SWITCH */
+        return 0;
     case 0xf000f:
         return PNV_CHIP_GET_CLASS(chip)->chip_cfam_id;
     case 0x18002:       /* ECID2 */
-- 
2.47.3