spapr: nested: Introduce H_GUEST_[GET|SET]_CAPABILITIES hcalls.

Introduce the nested PAPR hcalls:
 - H_GUEST_GET_CAPABILITIES which is used to query the capabilities
   of the API and the L2 guests it provides.
 - H_GUEST_SET_CAPABILITIES which is used to set the Guest API
   capabilities that the Host Partition supports and may use.

[amachhiw: support for p9 compat mode and return register bug fixes]

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Amit Machhiwal <amachhiw@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

hw/ppc/spapr_nested.c

@@ -7,6 +7,7 @@
 #include "hw/ppc/spapr_cpu_core.h"
 #include "hw/ppc/spapr_nested.h"
 #include "mmu-book3s-v3.h"
+#include "cpu-models.h"
 
 void spapr_nested_reset(SpaprMachineState *spapr)
 {
@@ -16,6 +17,7 @@ void spapr_nested_reset(SpaprMachineState *spapr)
         spapr_register_nested_hv();
     } else {
         spapr->nested.api = 0;
+        spapr->nested.capabilities_set = false;
     }
 }
 
@@ -432,6 +434,93 @@ void spapr_exit_nested(PowerPCCPU *cpu, int excp)
     }
 }
 
+static target_ulong h_guest_get_capabilities(PowerPCCPU *cpu,
+                                             SpaprMachineState *spapr,
+                                             target_ulong opcode,
+                                             target_ulong *args)
+{
+    CPUPPCState *env = &cpu->env;
+    target_ulong flags = args[0];
+
+    if (flags) { /* don't handle any flags capabilities for now */
+        return H_PARAMETER;
+    }
+
+    /* P10 capabilities */
+    if (ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_3_10, 0,
+        spapr->max_compat_pvr)) {
+        env->gpr[4] |= H_GUEST_CAPABILITIES_P10_MODE;
+    }
+
+    /* P9 capabilities */
+    if (ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_3_00, 0,
+        spapr->max_compat_pvr)) {
+        env->gpr[4] |= H_GUEST_CAPABILITIES_P9_MODE;
+    }
+
+    return H_SUCCESS;
+}
+
+static target_ulong h_guest_set_capabilities(PowerPCCPU *cpu,
+                                             SpaprMachineState *spapr,
+                                             target_ulong opcode,
+                                              target_ulong *args)
+{
+    CPUPPCState *env = &cpu->env;
+    target_ulong flags = args[0];
+    target_ulong capabilities = args[1];
+    env->gpr[4] = 0;
+
+    if (flags) { /* don't handle any flags capabilities for now */
+        return H_PARAMETER;
+    }
+
+    if (capabilities & H_GUEST_CAPABILITIES_COPY_MEM) {
+        env->gpr[4] = 1;
+        return H_P2; /* isn't supported */
+    }
+
+    /*
+     * If there are no capabilities configured, set the R5 to the index of
+     * the first supported Power Processor Mode
+     */
+    if (!capabilities) {
+        env->gpr[4] = 1;
+
+        /* set R5 to the first supported Power Processor Mode */
+        if (ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_3_10, 0,
+                             spapr->max_compat_pvr)) {
+            env->gpr[5] = H_GUEST_CAP_P10_MODE_BMAP;
+        } else if (ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_3_00, 0,
+                                    spapr->max_compat_pvr)) {
+            env->gpr[5] = H_GUEST_CAP_P9_MODE_BMAP;
+        }
+
+        return H_P2;
+    }
+
+    /*
+     * If an invalid capability is set, R5 should contain the index of the
+     * invalid capability bit
+     */
+    if (capabilities & ~H_GUEST_CAP_VALID_MASK) {
+        env->gpr[4] = 1;
+
+        /* Set R5 to the index of the invalid capability */
+        env->gpr[5] = 63 - ctz64(capabilities);
+
+        return H_P2;
+    }
+
+    if (!spapr->nested.capabilities_set) {
+        spapr->nested.capabilities_set = true;
+        spapr->nested.pvr_base = env->spr[SPR_PVR];
+        return H_SUCCESS;
+    } else {
+        return H_STATE;
+    }
+}
+
 void spapr_register_nested_hv(void)
 {
     spapr_register_hypercall(KVMPPC_H_SET_PARTITION_TABLE, h_set_ptbl);
@@ -447,6 +536,21 @@ void spapr_unregister_nested_hv(void)
     spapr_unregister_hypercall(KVMPPC_H_TLB_INVALIDATE);
     spapr_unregister_hypercall(KVMPPC_H_COPY_TOFROM_GUEST);
 }
+
+void spapr_register_nested_papr(void)
+{
+    spapr_register_hypercall(H_GUEST_GET_CAPABILITIES,
+                             h_guest_get_capabilities);
+    spapr_register_hypercall(H_GUEST_SET_CAPABILITIES,
+                             h_guest_set_capabilities);
+}
+
+void spapr_unregister_nested_papr(void)
+{
+    spapr_unregister_hypercall(H_GUEST_GET_CAPABILITIES);
+    spapr_unregister_hypercall(H_GUEST_SET_CAPABILITIES);
+}
+
 #else
 void spapr_exit_nested(PowerPCCPU *cpu, int excp)
 {
@@ -468,4 +572,15 @@ bool spapr_get_pate_nested_hv(SpaprMachineState *spapr, PowerPCCPU *cpu,
 {
     return false;
 }
+
+void spapr_register_nested_papr(void)
+{
+    /* DO NOTHING */
+}
+
+void spapr_unregister_nested_papr(void)
+{
+    /* DO NOTHING */
+}
+
 #endif

include/hw/ppc/spapr.h

@@ -364,6 +364,7 @@ struct SpaprMachineState {
 #define H_NOOP            -63
 #define H_UNSUPPORTED     -67
 #define H_OVERLAP         -68
+#define H_STATE           -75
 #define H_UNSUPPORTED_FLAG -256
 #define H_MULTI_THREADS_ACTIVE -9005
 
@@ -583,8 +584,10 @@ struct SpaprMachineState {
 #define H_RPT_INVALIDATE        0x448
 #define H_SCM_FLUSH             0x44C
 #define H_WATCHDOG              0x45C
+#define H_GUEST_GET_CAPABILITIES 0x460
+#define H_GUEST_SET_CAPABILITIES 0x464
 
-#define MAX_HCALL_OPCODE        H_WATCHDOG
+#define MAX_HCALL_OPCODE         H_GUEST_SET_CAPABILITIES
 
 /* The hcalls above are standardized in PAPR and implemented by pHyp
  * as well.
@@ -1033,5 +1036,7 @@ void spapr_watchdog_init(SpaprMachineState *spapr);
 void spapr_register_nested_hv(void);
 void spapr_unregister_nested_hv(void);
 void spapr_nested_reset(SpaprMachineState *spapr);
+void spapr_register_nested_papr(void);
+void spapr_unregister_nested_papr(void);
 
 #endif /* HW_SPAPR_H */

include/hw/ppc/spapr_nested.h

@@ -7,8 +7,20 @@ typedef struct SpaprMachineStateNested {
     uint64_t ptcr;
     uint8_t api;
 #define NESTED_API_KVM_HV  1
+    bool capabilities_set;
+    uint32_t pvr_base;
 } SpaprMachineStateNested;
 
+/* Nested PAPR API related macros */
+#define H_GUEST_CAPABILITIES_COPY_MEM 0x8000000000000000
+#define H_GUEST_CAPABILITIES_P9_MODE  0x4000000000000000
+#define H_GUEST_CAPABILITIES_P10_MODE 0x2000000000000000
+#define H_GUEST_CAP_VALID_MASK        (H_GUEST_CAPABILITIES_P10_MODE | \
+                                       H_GUEST_CAPABILITIES_P9_MODE)
+#define H_GUEST_CAP_COPY_MEM_BMAP     0
+#define H_GUEST_CAP_P9_MODE_BMAP      1
+#define H_GUEST_CAP_P10_MODE_BMAP     2
+
 /*
  * Register state for entering a nested guest with H_ENTER_NESTED.
  * New member must be added at the end.