spapr: Fix RTAS token numbers

At the moment spapr_rtas_register() allocates a new token number for every
new RTAS callback so numbers are not fixed and depend on the number of
supported RTAS handlers and the exact order of spapr_rtas_register() calls.
These tokens are copied into the device tree and remain the same during
the guest lifetime.

When we start another guest to receive a migration, it calls
spapr_rtas_register() as well. If the number of RTAS handlers or their
order is different in QEMU on source and destination sides, the "/rtas"
node in the device tree will differ. Since migration overwrites the device
tree (as it overwrites the entire RAM), the actual RTAS config on
the destination side gets broken.

This defines global contant values for every RTAS token which QEMU
is using today.

This changes spapr_rtas_register() to accept a token number instead of
allocating one. This changes all users of spapr_rtas_register().

This changes XICS-KVM not to cache tokens registered with KVM as they
constant now.

This makes TOKEN_BASE global as RTAS_XXX use TOKEN_BASE as
a base. TOKEN_MAX is moved and renamed too and its value is changed
to the last token + 1. Boundary checks for token values are adjusted.

This reserves token numbers for "os-term" handlers and PCI hotplug
which we are working on.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>

4 files changed, 50 insertions, 43 deletions

diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 16fa49e886..5ce96a7196 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -317,5 +317,6 @@ void spapr_events_init(sPAPREnvironment *spapr)
     spapr->epow_irq = spapr_allocate_msi(0);
     spapr->epow_notifier.notify = spapr_powerdown_req;
     qemu_register_powerdown_notifier(&spapr->epow_notifier);
-    spapr_rtas_register("check-exception", check_exception);
+    spapr_rtas_register(RTAS_CHECK_EXCEPTION, "check-exception",
+                        check_exception);
 }
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 988f8cb858..8607c88fd2 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -909,14 +909,20 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
 
 void spapr_pci_rtas_init(void)
 {
-    spapr_rtas_register("read-pci-config", rtas_read_pci_config);
-    spapr_rtas_register("write-pci-config", rtas_write_pci_config);
-    spapr_rtas_register("ibm,read-pci-config", rtas_ibm_read_pci_config);
-    spapr_rtas_register("ibm,write-pci-config", rtas_ibm_write_pci_config);
+    spapr_rtas_register(RTAS_READ_PCI_CONFIG, "read-pci-config",
+                        rtas_read_pci_config);
+    spapr_rtas_register(RTAS_WRITE_PCI_CONFIG, "write-pci-config",
+                        rtas_write_pci_config);
+    spapr_rtas_register(RTAS_IBM_READ_PCI_CONFIG, "ibm,read-pci-config",
+                        rtas_ibm_read_pci_config);
+    spapr_rtas_register(RTAS_IBM_WRITE_PCI_CONFIG, "ibm,write-pci-config",
+                        rtas_ibm_write_pci_config);
     if (msi_supported) {
-        spapr_rtas_register("ibm,query-interrupt-source-number",
+        spapr_rtas_register(RTAS_IBM_QUERY_INTERRUPT_SOURCE_NUMBER,
+                            "ibm,query-interrupt-source-number",
                             rtas_ibm_query_interrupt_source_number);
-        spapr_rtas_register("ibm,change-msi", rtas_ibm_change_msi);
+        spapr_rtas_register(RTAS_IBM_CHANGE_MSI, "ibm,change-msi",
+                            rtas_ibm_change_msi);
     }
 }
 
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 8d08539baa..4e87d02805 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -36,9 +36,6 @@
 
 #include <libfdt.h>
 
-#define TOKEN_BASE      0x2000
-#define TOKEN_MAX       0x100
-
 static void rtas_display_character(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                    uint32_t token, uint32_t nargs,
                                    target_ulong args,
@@ -271,17 +268,14 @@ static void rtas_ibm_set_system_parameter(PowerPCCPU *cpu,
 static struct rtas_call {
     const char *name;
     spapr_rtas_fn fn;
-} rtas_table[TOKEN_MAX];
-
-static struct rtas_call *rtas_next = rtas_table;
+} rtas_table[RTAS_TOKEN_MAX - RTAS_TOKEN_BASE];
 
 target_ulong spapr_rtas_call(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                              uint32_t token, uint32_t nargs, target_ulong args,
                              uint32_t nret, target_ulong rets)
 {
-    if ((token >= TOKEN_BASE)
-        && ((token - TOKEN_BASE) < TOKEN_MAX)) {
-        struct rtas_call *call = rtas_table + (token - TOKEN_BASE);
+    if ((token >= RTAS_TOKEN_BASE) && (token < RTAS_TOKEN_MAX)) {
+        struct rtas_call *call = rtas_table + (token - RTAS_TOKEN_BASE);
 
         if (call->fn) {
             call->fn(cpu, spapr, token, nargs, args, nret, rets);
@@ -303,23 +297,22 @@ target_ulong spapr_rtas_call(PowerPCCPU *cpu, sPAPREnvironment *spapr,
     return H_PARAMETER;
 }
 
-int spapr_rtas_register(const char *name, spapr_rtas_fn fn)
+void spapr_rtas_register(int token, const char *name, spapr_rtas_fn fn)
 {
-    int i;
-
-    for (i = 0; i < (rtas_next - rtas_table); i++) {
-        if (strcmp(name, rtas_table[i].name) == 0) {
-            fprintf(stderr, "RTAS call \"%s\" registered twice\n", name);
-            exit(1);
-        }
+    if (!((token >= RTAS_TOKEN_BASE) && (token < RTAS_TOKEN_MAX))) {
+        fprintf(stderr, "RTAS invalid token 0x%x\n", token);
+        exit(1);
     }
 
-    assert(rtas_next < (rtas_table + TOKEN_MAX));
-
-    rtas_next->name = name;
-    rtas_next->fn = fn;
+    token -= RTAS_TOKEN_BASE;
+    if (rtas_table[token].name) {
+        fprintf(stderr, "RTAS call \"%s\" is registered already as 0x%x\n",
+                rtas_table[token].name, token);
+        exit(1);
+    }
 
-    return (rtas_next++ - rtas_table) + TOKEN_BASE;
+    rtas_table[token].name = name;
+    rtas_table[token].fn = fn;
 }
 
 int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
@@ -359,7 +352,7 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
         return ret;
     }
 
-    for (i = 0; i < TOKEN_MAX; i++) {
+    for (i = 0; i < RTAS_TOKEN_MAX - RTAS_TOKEN_BASE; i++) {
         struct rtas_call *call = &rtas_table[i];
 
         if (!call->name) {
@@ -367,7 +360,7 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
         }
 
         ret = qemu_fdt_setprop_cell(fdt, "/rtas", call->name,
-                                    i + TOKEN_BASE);
+                                    i + RTAS_TOKEN_BASE);
         if (ret < 0) {
             fprintf(stderr, "Couldn't add rtas token for %s: %s\n",
                     call->name, fdt_strerror(ret));
@@ -380,18 +373,24 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
 
 static void core_rtas_register_types(void)
 {
-    spapr_rtas_register("display-character", rtas_display_character);
-    spapr_rtas_register("get-time-of-day", rtas_get_time_of_day);
-    spapr_rtas_register("set-time-of-day", rtas_set_time_of_day);
-    spapr_rtas_register("power-off", rtas_power_off);
-    spapr_rtas_register("system-reboot", rtas_system_reboot);
-    spapr_rtas_register("query-cpu-stopped-state",
+    spapr_rtas_register(RTAS_DISPLAY_CHARACTER, "display-character",
+                        rtas_display_character);
+    spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
+                        rtas_get_time_of_day);
+    spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
+                        rtas_set_time_of_day);
+    spapr_rtas_register(RTAS_POWER_OFF, "power-off", rtas_power_off);
+    spapr_rtas_register(RTAS_SYSTEM_REBOOT, "system-reboot",
+                        rtas_system_reboot);
+    spapr_rtas_register(RTAS_QUERY_CPU_STOPPED_STATE, "query-cpu-stopped-state",
                         rtas_query_cpu_stopped_state);
-    spapr_rtas_register("start-cpu", rtas_start_cpu);
-    spapr_rtas_register("stop-self", rtas_stop_self);
-    spapr_rtas_register("ibm,get-system-parameter",
+    spapr_rtas_register(RTAS_START_CPU, "start-cpu", rtas_start_cpu);
+    spapr_rtas_register(RTAS_STOP_SELF, "stop-self", rtas_stop_self);
+    spapr_rtas_register(RTAS_IBM_GET_SYSTEM_PARAMETER,
+                        "ibm,get-system-parameter",
                         rtas_ibm_get_system_parameter);
-    spapr_rtas_register("ibm,set-system-parameter",
+    spapr_rtas_register(RTAS_IBM_SET_SYSTEM_PARAMETER,
+                        "ibm,set-system-parameter",
                         rtas_ibm_set_system_parameter);
 }
 
diff --git a/hw/ppc/spapr_vio.c b/hw/ppc/spapr_vio.c
index 04e16ae04d..a195fd1565 100644
--- a/hw/ppc/spapr_vio.c
+++ b/hw/ppc/spapr_vio.c
@@ -517,8 +517,9 @@ VIOsPAPRBus *spapr_vio_bus_init(void)
     spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
 
     /* RTAS calls */
-    spapr_rtas_register("ibm,set-tce-bypass", rtas_set_tce_bypass);
-    spapr_rtas_register("quiesce", rtas_quiesce);
+    spapr_rtas_register(RTAS_IBM_SET_TCE_BYPASS, "ibm,set-tce-bypass",
+                        rtas_set_tce_bypass);
+    spapr_rtas_register(RTAS_QUIESCE, "quiesce", rtas_quiesce);
 
     return bus;
 }