ppc/pnv: Return zero for core thread state xscom

Firmware now warns if booting in LPAR per core mode (PPC bit 62). So
this warning doesn't trigger, report the core thread state is 0.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Message-ID: <20230704054204.168547-6-joel@jms.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

hw/ppc/pnv_core.c

@@ -116,6 +116,8 @@ static const MemoryRegionOps pnv_core_power8_xscom_ops = {
 #define PNV9_XSCOM_EC_PPM_SPECIAL_WKUP_HYP 0xf010d
 #define PNV9_XSCOM_EC_PPM_SPECIAL_WKUP_OTR 0xf010a
 
+#define PNV9_XSCOM_EC_CORE_THREAD_STATE    0x10ab3
+
 static uint64_t pnv_core_power9_xscom_read(void *opaque, hwaddr addr,
                                            unsigned int width)
 {
@@ -134,6 +136,9 @@ static uint64_t pnv_core_power9_xscom_read(void *opaque, hwaddr addr,
     case PNV9_XSCOM_EC_PPM_SPECIAL_WKUP_OTR:
         val = 0x0;
         break;
+    case PNV9_XSCOM_EC_CORE_THREAD_STATE:
+        val = 0;
+        break;
     default:
         qemu_log_mask(LOG_UNIMP, "Warning: reading reg=0x%" HWADDR_PRIx "\n",
                   addr);
@@ -171,13 +176,18 @@ static const MemoryRegionOps pnv_core_power9_xscom_ops = {
  * POWER10 core controls
  */
 
+#define PNV10_XSCOM_EC_CORE_THREAD_STATE    0x412
+
 static uint64_t pnv_core_power10_xscom_read(void *opaque, hwaddr addr,
                                            unsigned int width)
 {
     uint32_t offset = addr >> 3;
     uint64_t val = 0;
 
     switch (offset) {
+    case PNV10_XSCOM_EC_CORE_THREAD_STATE:
+        val = 0;
+        break;
     default:
         qemu_log_mask(LOG_UNIMP, "Warning: reading reg=0x%" HWADDR_PRIx "\n",
                   addr);