target/s390x/cpu topology: handle STSI(15) and build the SYSIB

On interception of STSI(15.1.x) the System Information Block
(SYSIB) is built from the list of pre-ordered topology entries.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Message-ID: <20231016183925.2384704-5-nsg@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

MAINTAINERS

@@ -1715,6 +1715,7 @@ M: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
 S: Supported
 F: include/hw/s390x/cpu-topology.h
 F: hw/s390x/cpu-topology.c
+F: target/s390x/kvm/stsi-topology.c
 
 X86 Machines
 ------------

hw/s390x/cpu-topology.c

@@ -28,10 +28,12 @@
  * s390_topology is used to keep the topology information.
  * .cores_per_socket: tracks information on the count of cores
  *                    per socket.
+ * .polarization: tracks machine polarization.
  */
 S390Topology s390_topology = {
     /* will be initialized after the CPU model is realized */
     .cores_per_socket = NULL,
+    .polarization = S390_CPU_POLARIZATION_HORIZONTAL,
 };
 
 /**

include/hw/s390x/cpu-topology.h

@@ -15,10 +15,33 @@
 #include "hw/boards.h"
 #include "qapi/qapi-types-machine-target.h"
 
+#define S390_TOPOLOGY_CPU_IFL   0x03
+
+typedef struct S390TopologyId {
+    uint8_t sentinel;
+    uint8_t drawer;
+    uint8_t book;
+    uint8_t socket;
+    uint8_t type;
+    uint8_t vertical:1;
+    uint8_t entitlement:2;
+    uint8_t dedicated;
+    uint8_t origin;
+} S390TopologyId;
+
+typedef struct S390TopologyEntry {
+    QTAILQ_ENTRY(S390TopologyEntry) next;
+    S390TopologyId id;
+    uint64_t mask;
+} S390TopologyEntry;
+
 typedef struct S390Topology {
     uint8_t *cores_per_socket;
+    CpuS390Polarization polarization;
 } S390Topology;
 
+typedef QTAILQ_HEAD(, S390TopologyEntry) S390TopologyList;
+
 #ifdef CONFIG_KVM
 bool s390_has_topology(void);
 void s390_topology_setup_cpu(MachineState *ms, S390CPU *cpu, Error **errp);

include/hw/s390x/sclp.h

@@ -112,6 +112,7 @@ typedef struct CPUEntry {
 } QEMU_PACKED CPUEntry;
 
 #define SCLP_READ_SCP_INFO_FIXED_CPU_OFFSET     128
+#define SCLP_READ_SCP_INFO_MNEST                2
 typedef struct ReadInfo {
     SCCBHeader h;
     uint16_t rnmax;

qapi/machine-target.json

@@ -361,3 +361,17 @@
                    'TARGET_MIPS',
                    'TARGET_LOONGARCH64',
                    'TARGET_RISCV' ] } }
+
+##
+# @CpuS390Polarization:
+#
+# An enumeration of CPU polarization that can be assumed by a virtual
+# S390 CPU
+#
+# Since: 8.2
+##
+{ 'enum': 'CpuS390Polarization',
+  'prefix': 'S390_CPU_POLARIZATION',
+  'data': [ 'horizontal', 'vertical' ],
+  'if': 'TARGET_S390X'
+}

target/s390x/cpu.h

@@ -570,16 +570,91 @@ typedef struct SysIB_322 {
 } SysIB_322;
 QEMU_BUILD_BUG_ON(sizeof(SysIB_322) != 4096);
 
+/*
+ * Topology Magnitude fields (MAG) indicates the maximum number of
+ * topology list entries (TLE) at the corresponding nesting level.
+ */
+#define S390_TOPOLOGY_MAG  6
+#define S390_TOPOLOGY_MAG6 0
+#define S390_TOPOLOGY_MAG5 1
+#define S390_TOPOLOGY_MAG4 2
+#define S390_TOPOLOGY_MAG3 3
+#define S390_TOPOLOGY_MAG2 4
+#define S390_TOPOLOGY_MAG1 5
+/* Configuration topology */
+typedef struct SysIB_151x {
+    uint8_t  reserved0[2];
+    uint16_t length;
+    uint8_t  mag[S390_TOPOLOGY_MAG];
+    uint8_t  reserved1;
+    uint8_t  mnest;
+    uint32_t reserved2;
+    char tle[];
+} SysIB_151x;
+QEMU_BUILD_BUG_ON(sizeof(SysIB_151x) != 16);
+
 typedef union SysIB {
     SysIB_111 sysib_111;
     SysIB_121 sysib_121;
     SysIB_122 sysib_122;
     SysIB_221 sysib_221;
     SysIB_222 sysib_222;
     SysIB_322 sysib_322;
+    SysIB_151x sysib_151x;
 } SysIB;
 QEMU_BUILD_BUG_ON(sizeof(SysIB) != 4096);
 
+/*
+ * CPU Topology List provided by STSI with fc=15 provides a list
+ * of two different Topology List Entries (TLE) types to specify
+ * the topology hierarchy.
+ *
+ * - Container Topology List Entry
+ *   Defines a container to contain other Topology List Entries
+ *   of any type, nested containers or CPU.
+ * - CPU Topology List Entry
+ *   Specifies the CPUs position, type, entitlement and polarization
+ *   of the CPUs contained in the last container TLE.
+ *
+ * There can be theoretically up to five levels of containers, QEMU
+ * uses only three levels, the drawer's, book's and socket's level.
+ *
+ * A container with a nesting level (NL) greater than 1 can only
+ * contain another container of nesting level NL-1.
+ *
+ * A container of nesting level 1 (socket), contains as many CPU TLE
+ * as needed to describe the position and qualities of all CPUs inside
+ * the container.
+ * The qualities of a CPU are polarization, entitlement and type.
+ *
+ * The CPU TLE defines the position of the CPUs of identical qualities
+ * using a 64bits mask which first bit has its offset defined by
+ * the CPU address origin field of the CPU TLE like in:
+ * CPU address = origin * 64 + bit position within the mask
+ */
+/* Container type Topology List Entry */
+typedef struct SYSIBContainerListEntry {
+        uint8_t nl;
+        uint8_t reserved[6];
+        uint8_t id;
+} SYSIBContainerListEntry;
+QEMU_BUILD_BUG_ON(sizeof(SYSIBContainerListEntry) != 8);
+
+/* CPU type Topology List Entry */
+typedef struct SysIBCPUListEntry {
+        uint8_t nl;
+        uint8_t reserved0[3];
+#define SYSIB_TLE_POLARITY_MASK 0x03
+#define SYSIB_TLE_DEDICATED     0x04
+        uint8_t flags;
+        uint8_t type;
+        uint16_t origin;
+        uint64_t mask;
+} SysIBCPUListEntry;
+QEMU_BUILD_BUG_ON(sizeof(SysIBCPUListEntry) != 16);
+
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, uint64_t addr, uint8_t ar, uintptr_t ra);
+
 /* MMU defines */
 #define ASCE_ORIGIN           (~0xfffULL) /* segment table origin             */
 #define ASCE_SUBSPACE         0x200       /* subspace group control           */

target/s390x/kvm/kvm.c

@@ -1911,9 +1911,12 @@ static int handle_stsi(S390CPU *cpu)
         if (run->s390_stsi.sel1 != 2 || run->s390_stsi.sel2 != 2) {
             return 0;
         }
-        /* Only sysib 3.2.2 needs post-handling for now. */
         insert_stsi_3_2_2(cpu, run->s390_stsi.addr, run->s390_stsi.ar);
         return 0;
+    case 15:
+        insert_stsi_15_1_x(cpu, run->s390_stsi.sel2, run->s390_stsi.addr,
+                           run->s390_stsi.ar, RA_IGNORED);
+        return 0;
     default:
         return 0;
     }

target/s390x/kvm/meson.build

@@ -1,7 +1,8 @@
 
 s390x_ss.add(when: 'CONFIG_KVM', if_true: files(
   'pv.c',
-  'kvm.c'
+  'kvm.c',
+  'stsi-topology.c'
 ), if_false: files(
   'stubs.c'
 ))