ppc/spapr: Implement H_WATCHDOG

The new PAPR 2.12 defines a watchdog facility managed via the new
H_WATCHDOG hypercall.

This adds H_WATCHDOG support which a proposed driver for pseries uses:
https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=303120

This was tested by running QEMU with a debug kernel and command line:
-append \
 "pseries-wdt.timeout=60 pseries-wdt.nowayout=1 pseries-wdt.action=2"

and running "echo V > /dev/watchdog0" inside the VM.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220622051008.1067464-1-aik@ozlabs.ru>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 4ba2b27b8c..530d739b1d 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -164,6 +164,21 @@ struct SpaprMachineClass {
     SpaprIrq *irq;
 };
 
+#define WDT_MAX_WATCHDOGS       4      /* Maximum number of watchdog devices */
+
+#define TYPE_SPAPR_WDT "spapr-wdt"
+OBJECT_DECLARE_SIMPLE_TYPE(SpaprWatchdog, SPAPR_WDT)
+
+typedef struct SpaprWatchdog {
+    /*< private >*/
+    DeviceState parent_obj;
+    /*< public >*/
+
+    QEMUTimer timer;
+    uint8_t action;         /* One of PSERIES_WDTF_ACTION_xxx */
+    uint8_t leave_others;   /* leaveOtherWatchdogsRunningOnTimeout */
+} SpaprWatchdog;
+
 /**
  * SpaprMachineState:
  */
@@ -264,6 +279,8 @@ struct SpaprMachineState {
     uint32_t FORM2_assoc_array[NUMA_NODES_MAX_NUM][FORM2_NUMA_ASSOC_SIZE];
 
     Error *fwnmi_migration_blocker;
+
+    SpaprWatchdog wds[WDT_MAX_WATCHDOGS];
 };
 
 #define H_SUCCESS         0
@@ -344,6 +361,7 @@ struct SpaprMachineState {
 #define H_P7              -60
 #define H_P8              -61
 #define H_P9              -62
+#define H_NOOP            -63
 #define H_UNSUPPORTED     -67
 #define H_OVERLAP         -68
 #define H_UNSUPPORTED_FLAG -256
@@ -564,8 +582,9 @@ struct SpaprMachineState {
 #define H_SCM_HEALTH            0x400
 #define H_RPT_INVALIDATE        0x448
 #define H_SCM_FLUSH             0x44C
+#define H_WATCHDOG              0x45C
 
-#define MAX_HCALL_OPCODE        H_SCM_FLUSH
+#define MAX_HCALL_OPCODE        H_WATCHDOG
 
 /* The hcalls above are standardized in PAPR and implemented by pHyp
  * as well.
@@ -1028,6 +1047,7 @@ extern const VMStateDescription vmstate_spapr_cap_large_decr;
 extern const VMStateDescription vmstate_spapr_cap_ccf_assist;
 extern const VMStateDescription vmstate_spapr_cap_fwnmi;
 extern const VMStateDescription vmstate_spapr_cap_rpt_invalidate;
+extern const VMStateDescription vmstate_spapr_wdt;
 
 static inline uint8_t spapr_get_cap(SpaprMachineState *spapr, int cap)
 {
@@ -1064,4 +1084,7 @@ target_ulong spapr_vof_client_architecture_support(MachineState *ms,
                                                    target_ulong ovec_addr);
 void spapr_vof_client_dt_finalize(SpaprMachineState *spapr, void *fdt);
 
+/* H_WATCHDOG */
+void spapr_watchdog_init(SpaprMachineState *spapr);
+
 #endif /* HW_SPAPR_H */