[PATCH v4 06/15] spapr: nested: Introduce H_GUEST_[GET|SET]_CAPABILITIES hcalls.

[Harsh Prateek Bora]

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]

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>
---
 include/hw/ppc/spapr.h        |   6 +-
 include/hw/ppc/spapr_nested.h |  12 ++++
 hw/ppc/spapr_nested.c         | 100 ++++++++++++++++++++++++++++++++++
 3 files changed, 117 insertions(+), 1 deletion(-)

diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 63e9d4c476..d745d487a1 100644
--- a/include/hw/ppc/spapr.h
+++ b/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.
@@ -1029,5 +1032,6 @@ void spapr_vof_client_dt_finalize(SpaprMachineState 
*spapr, void *fdt);
 void spapr_watchdog_init(SpaprMachineState *spapr);
 void spapr_register_nested_hv(void);
 void spapr_unregister_nested_hv(void);
+void spapr_register_nested_papr(void);
 
 #endif /* HW_SPAPR_H */
diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h
index 3f07c81c3d..599373692b 100644
--- a/include/hw/ppc/spapr_nested.h
+++ b/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.
diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c
index 9096dd96a4..012af27881 100644
--- a/hw/ppc/spapr_nested.c
+++ b/hw/ppc/spapr_nested.c
@@ -7,10 +7,12 @@
 #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_init(SpaprMachineState *spapr)
 {
     spapr->nested.api = 0;
+    spapr->nested.capabilities_set = false;
 }
 
 uint8_t spapr_nested_api(SpaprMachineState *spapr)
@@ -426,6 +428,92 @@ 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);
@@ -441,6 +529,13 @@ 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);
+}
+
 #else
 void spapr_exit_nested(PowerPCCPU *cpu, int excp)
 {
@@ -462,4 +557,9 @@ bool spapr_get_pate_nested_hv(SpaprMachineState *spapr, 
PowerPCCPU *cpu,
 {
     return false;
 }
+
+void spapr_register_nested_papr(void)
+{
+    /* DO NOTHING */
+}
 #endif
-- 
2.39.3