[PATCH v2 08/14] spapr: nested: Introduce H_GUEST_CREATE_VPCU hcall.

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

Introduce the nested PAPR hcall H_GUEST_CREATE_VCPU which is used to
create and initialize the specified VCPU resource for the previously
created guest. Each guest can have multiple VCPUs upto max 2048.
All VCPUs for a guest gets deallocated on guest delete.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
---
 hw/ppc/spapr_nested.c         | 100 ++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h        |   2 +
 include/hw/ppc/spapr_nested.h |   8 +++
 3 files changed, 110 insertions(+)

diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c
index e95e70e20c..b38116b7c3 100644
--- a/hw/ppc/spapr_nested.c
+++ b/hw/ppc/spapr_nested.c
@@ -411,6 +411,41 @@ void spapr_exit_nested(PowerPCCPU *cpu, int excp)
     address_space_unmap(CPU(cpu)->as, regs, len, len, true);
 }
 
+static
+SpaprMachineStateNestedGuest *spapr_get_nested_guest(SpaprMachineState *spapr,
+                                                     target_ulong guestid)
+{
+    SpaprMachineStateNestedGuest *guest;
+
+    guest = g_hash_table_lookup(spapr->nested.guests, GINT_TO_POINTER(guestid));
+    return guest;
+}
+
+static bool spapr_nested_vcpu_check(SpaprMachineStateNestedGuest *guest,
+                                    target_ulong vcpuid)
+{
+    struct SpaprMachineStateNestedGuestVcpu *vcpu;
+    /*
+     * Perform sanity checks for the provided vcpuid of a guest.
+     * For now, ensure its valid, allocated and enabled for use.
+     */
+
+    if (vcpuid >= PAPR_NESTED_GUEST_VCPU_MAX) {
+        return false;
+    }
+
+    if (!(vcpuid < guest->vcpus)) {
+        return false;
+    }
+
+    vcpu = &guest->vcpu[vcpuid];
+    if (!vcpu->enabled) {
+        return false;
+    }
+
+    return true;
+}
+
 static target_ulong h_guest_get_capabilities(PowerPCCPU *cpu,
                                              SpaprMachineState *spapr,
                                              target_ulong opcode,
@@ -481,6 +516,11 @@ static void
 destroy_guest_helper(gpointer value)
 {
     struct SpaprMachineStateNestedGuest *guest = value;
+
+    for (int i = 0; i < guest->vcpus; i++) {
+        cpu_ppc_tb_free(&guest->vcpu[i].env);
+    }
+    g_free(guest->vcpu);
     g_free(guest);
 }
 
@@ -576,6 +616,65 @@ static target_ulong h_guest_delete(PowerPCCPU *cpu,
     return H_SUCCESS;
 }
 
+static target_ulong h_guest_create_vcpu(PowerPCCPU *cpu,
+                                        SpaprMachineState *spapr,
+                                        target_ulong opcode,
+                                        target_ulong *args)
+{
+    CPUPPCState *env = &cpu->env, *l2env;
+    target_ulong flags = args[0];
+    target_ulong guestid = args[1];
+    target_ulong vcpuid = args[2];
+    SpaprMachineStateNestedGuest *guest;
+
+    if (flags) { /* don't handle any flags for now */
+        return H_UNSUPPORTED_FLAG;
+    }
+
+    guest = spapr_get_nested_guest(spapr, guestid);
+    if (!guest) {
+        return H_P2;
+    }
+
+    if (vcpuid < guest->vcpus) {
+        return H_IN_USE;
+    }
+
+    if (guest->vcpus >= PAPR_NESTED_GUEST_VCPU_MAX) {
+        return H_P3;
+    }
+
+    if (guest->vcpus) {
+        SpaprMachineStateNestedGuestVcpu *vcpus;
+        vcpus = g_try_renew(struct SpaprMachineStateNestedGuestVcpu,
+                            guest->vcpu,
+                            guest->vcpus + 1);
+        if (!vcpus) {
+            return H_NO_MEM;
+        }
+        memset(&vcpus[guest->vcpus], 0,
+               sizeof(SpaprMachineStateNestedGuestVcpu));
+        guest->vcpu = vcpus;
+    } else {
+        guest->vcpu = g_try_new0(SpaprMachineStateNestedGuestVcpu, 1);
+        if (guest->vcpu == NULL) {
+            return H_NO_MEM;
+        }
+    }
+    l2env = &guest->vcpu[guest->vcpus].env;
+    guest->vcpus++;
+    assert(vcpuid < guest->vcpus); /* linear vcpuid allocation only */
+    /* Copy L1 PVR to L2 */
+    l2env->spr[SPR_PVR] = env->spr[SPR_PVR];
+    cpu_ppc_tb_init(l2env, SPAPR_TIMEBASE_FREQ);
+    guest->vcpu[vcpuid].enabled = true;
+
+    if (!spapr_nested_vcpu_check(guest, vcpuid)) {
+        return H_PARAMETER;
+    }
+    return H_SUCCESS;
+}
+
 void spapr_register_nested(void)
 {
     spapr_register_hypercall(KVMPPC_H_SET_PARTITION_TABLE, h_set_ptbl);
@@ -591,6 +690,7 @@ void spapr_register_nested_papr(void)
     spapr_register_hypercall(H_GUEST_SET_CAPABILITIES, h_guest_set_capabilities);
     spapr_register_hypercall(H_GUEST_CREATE          , h_guest_create);
     spapr_register_hypercall(H_GUEST_DELETE          , h_guest_delete);
+    spapr_register_hypercall(H_GUEST_CREATE_VCPU     , h_guest_create_vcpu);
 }
 #else
 void spapr_exit_nested(PowerPCCPU *cpu, int excp)
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index fcc6f0a3d9..25aa8c5ffe 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -367,6 +367,7 @@ struct SpaprMachineState {
 #define H_UNSUPPORTED     -67
 #define H_OVERLAP         -68
 #define H_STATE           -75
+#define H_IN_USE          -77
 #define H_UNSUPPORTED_FLAG -256
 #define H_MULTI_THREADS_ACTIVE -9005
 
@@ -589,6 +590,7 @@ struct SpaprMachineState {
 #define H_GUEST_GET_CAPABILITIES 0x460
 #define H_GUEST_SET_CAPABILITIES 0x464
 #define H_GUEST_CREATE           0x470
+#define H_GUEST_CREATE_VCPU      0x474
 #define H_GUEST_DELETE           0x488
 
 #define MAX_HCALL_OPCODE         H_GUEST_DELETE
diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h
index f186005f00..91cb744a5b 100644
--- a/include/hw/ppc/spapr_nested.h
+++ b/include/hw/ppc/spapr_nested.h
@@ -16,8 +16,15 @@ typedef struct SpaprMachineStateNested {
 
 typedef struct SpaprMachineStateNestedGuest {
     uint32_t pvr_logical;
+    unsigned long vcpus;
+    struct SpaprMachineStateNestedGuestVcpu *vcpu;
 } SpaprMachineStateNestedGuest;
 
+typedef struct SpaprMachineStateNestedGuestVcpu {
+    bool enabled;
+    CPUPPCState env;
+} SpaprMachineStateNestedGuestVcpu;
+
 /* Nested PAPR API related macros */
 #define H_GUEST_CAPABILITIES_COPY_MEM 0x8000000000000000
 #define H_GUEST_CAPABILITIES_P9_MODE  0x4000000000000000
@@ -27,6 +34,7 @@ typedef struct SpaprMachineStateNestedGuest {
 #define H_GUEST_CAP_P10_MODE_BMAP     2
 #define PAPR_NESTED_GUEST_MAX         4096
 #define H_GUEST_DELETE_ALL_FLAG       0x8000000000000000ULL
+#define PAPR_NESTED_GUEST_VCPU_MAX    2048
 
 /*
  * Register state for entering a nested guest with H_ENTER_NESTED.
-- 
2.39.3