[PATCH v16 03/11] target/s390x/cpu topology: handle STSI(15) and build the SYSIB

Pierre Morel
2023-02-22T14:21:36Z

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>
---
include/hw/s390x/cpu-topology.h | 21 +++
include/hw/s390x/sclp.h | 1 +
target/s390x/cpu.h | 72 ++++++++
hw/s390x/cpu-topology.c | 14 +-
target/s390x/kvm/cpu_topology.c | 312 ++++++++++++++++++++++++++++++++
target/s390x/kvm/kvm.c | 5 +-
target/s390x/kvm/meson.build | 3 +-
7 files changed, 425 insertions(+), 3 deletions(-)
create mode 100644 target/s390x/kvm/cpu_topology.c

diff --git a/include/hw/s390x/cpu-topology.h b/include/hw/s390x/cpu-topology.h
index fa7f885a9f..8dc42d2942 100644
--- a/include/hw/s390x/cpu-topology.h
+++ b/include/hw/s390x/cpu-topology.h
@@ -16,8 +16,29 @@

#define S390_TOPOLOGY_CPU_IFL 0x03

+typedef union s390_topology_id {
+ uint64_t id;
+ struct {
+ uint8_t level5;
+ uint8_t drawer;
+ uint8_t book;
+ uint8_t socket;
+ uint8_t dedicated;
+ uint8_t entitlement;
+ uint8_t type;
+ uint8_t origin;
+ };
+} s390_topology_id;
+
+typedef struct S390TopologyEntry {
+ QTAILQ_ENTRY(S390TopologyEntry) next;
+ s390_topology_id id;
+ uint64_t mask;
+} S390TopologyEntry;
+
typedef struct S390Topology {
uint8_t *cores_per_socket;
+ QTAILQ_HEAD(, S390TopologyEntry) list;
CpuTopology *smp;
CpuS390Polarization polarization;
} S390Topology;
diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
index d3ade40a5a..712fd68123 100644
--- a/include/hw/s390x/sclp.h
+++ b/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;
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index d654267a71..c899f4e04b 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -560,6 +560,25 @@ typedef struct SysIB_322 {
} SysIB_322;
QEMU_BUILD_BUG_ON(sizeof(SysIB_322) != 4096);

+#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[];
+} QEMU_PACKED QEMU_ALIGNED(8) SysIB_151x;
+QEMU_BUILD_BUG_ON(sizeof(SysIB_151x) != 16);
+
typedef union SysIB {
SysIB_111 sysib_111;
SysIB_121 sysib_121;
@@ -567,9 +586,62 @@ typedef union SysIB {
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 of 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 orgin field of the CPU TLE like in:
+ * CPU address = origin * 64 + bit position within the mask
+ *
+ */
+/* Container type Topology List Entry */
+typedef struct SysIBTl_container {
+ uint8_t nl;
+ uint8_t reserved[6];
+ uint8_t id;
+} QEMU_PACKED QEMU_ALIGNED(8) SysIBTl_container;
+QEMU_BUILD_BUG_ON(sizeof(SysIBTl_container) != 8);
+
+/* CPU type Topology List Entry */
+typedef struct SysIBTl_cpu {
+ 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;
+} QEMU_PACKED QEMU_ALIGNED(8) SysIBTl_cpu;
+QEMU_BUILD_BUG_ON(sizeof(SysIBTl_cpu) != 16);
+
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, uint64_t addr, uint8_t ar);
+
/* MMU defines */
#define ASCE_ORIGIN (~0xfffULL) /* segment table origin */
#define ASCE_SUBSPACE 0x200 /* subspace group control */
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 59f2cc15c7..85ad9ef0d7 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -18,12 +18,15 @@
#include "target/s390x/cpu.h"
#include "hw/s390x/s390-virtio-ccw.h"
#include "hw/s390x/cpu-topology.h"
-
+#include "qapi/qapi-types-machine-target.h"
/*
* s390_topology is used to keep the topology information.
* .cores_per_socket: tracks information on the count of cores
* per socket.
* .smp: keeps track of the machine topology.
+ * .list: queue the topology entries inside which
+ * we keep the information on the CPU topology.
+ * .polarization: the current subsystem polarization
*
*/
S390Topology s390_topology = {
@@ -31,6 +34,7 @@ S390Topology s390_topology = {
.cores_per_socket = NULL,
.smp = NULL,
.polarization = S390_CPU_POLARIZATION_HORIZONTAL,
+ .list = QTAILQ_HEAD_INITIALIZER(s390_topology.list),
};

/**
@@ -65,14 +69,22 @@ bool s390_has_topology(void)
* Allocate an array to keep the count of cores per socket.
* The index of the array starts at socket 0 from book 0 and
* drawer 0 up to the maximum allowed by the machine topology.
+ *
+ * Insert a sentinel entry using unused level5 with its maximum value.
+ * This entry will never be free.
*/
static void s390_topology_init(MachineState *ms)
{
CpuTopology *smp = &ms->smp;
+ S390TopologyEntry *entry;

s390_topology.smp = smp;
s390_topology.cores_per_socket = g_new0(uint8_t, smp->sockets *
smp->books * smp->drawers);
+
+ entry = g_malloc0(sizeof(S390TopologyEntry));
+ entry->id.level5 = 0xff;
+ QTAILQ_INSERT_HEAD(&s390_topology.list, entry, next);
}

/**
diff --git a/target/s390x/kvm/cpu_topology.c b/target/s390x/kvm/cpu_topology.c
new file mode 100644
index 0000000000..1b087269e5
--- /dev/null
+++ b/target/s390x/kvm/cpu_topology.c
@@ -0,0 +1,312 @@
+/*
+ * QEMU S390x CPU Topology
+ *
+ * Copyright IBM Corp. 2022
+ * Author(s): Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "hw/s390x/pv.h"
+#include "hw/sysbus.h"
+#include "hw/s390x/sclp.h"
+#include "hw/s390x/cpu-topology.h"
+#include "qapi/qapi-types-machine.h"
+#include "qapi/qapi-types-machine-target.h"
+
+/**
+ * fill_container:
+ * @p: The address of the container TLE to fill
+ * @level: The level of nesting for this container
+ * @id: The container receives a uniq ID inside its own container
+ *
+ * Returns the next free TLE entry.
+ */
+static char *fill_container(char *p, int level, int id)
+{
+ SysIBTl_container *tle = (SysIBTl_container *)p;
+
+ tle->nl = level;
+ tle->id = id;
+ return p + sizeof(*tle);
+}
+
+/**
+ * fill_tle_cpu:
+ * @p: The address of the CPU TLE to fill
+ * @entry: a pointer to the S390TopologyEntry defining this
+ * CPU container.
+ *
+ * Returns the next free TLE entry.
+ */
+static char *fill_tle_cpu(char *p, S390TopologyEntry *entry)
+{
+ SysIBTl_cpu *tle = (SysIBTl_cpu *)p;
+ s390_topology_id topology_id = entry->id;
+
+ tle->nl = 0;
+ if (topology_id.dedicated) {
+ tle->flags = SYSIB_TLE_DEDICATED;
+ }
+ tle->flags |= topology_id.entitlement;
+ tle->type = topology_id.type;
+ tle->origin = cpu_to_be16(topology_id.origin * 64);
+ tle->mask = cpu_to_be64(entry->mask);
+ return p + sizeof(*tle);
+}
+
+/*
+ * Macro to check that the size of data after increment
+ * will not get bigger than the size of the SysIB.
+ */
+#define SYSIB_GUARD(data, x) do { \
+ data += x; \
+ if (data > sizeof(SysIB)) { \
+ return 0; \
+ } \
+ } while (0)
+
+/**
+ * stsi_topology_fill_sysib:
+ * @p: A pointer to the position of the first TLE
+ * @level: The nested level wanted by the guest
+ *
+ * Fill the SYSIB with the topology information as described in
+ * the PoP, nesting containers as appropriate, with the maximum
+ * nesting limited by @level.
+ *
+ * Return value:
+ * On success: the size of the SysIB_15x after being filled with TLE.
+ * On error: 0 in the case we would overrun the end of the SysIB.
+ */
+static int stsi_topology_fill_sysib(char *p, int level)
+{
+ S390TopologyEntry *entry;
+ int last_drawer = -1;
+ int last_book = -1;
+ int last_socket = -1;
+ int drawer_id = 0;
+ int book_id = 0;
+ int socket_id = 0;
+ int n = sizeof(SysIB_151x);
+
+ QTAILQ_FOREACH(entry, &s390_topology.list, next) {
+ bool drawer_change = last_drawer != entry->id.drawer;
+ bool book_change = drawer_change || last_book != entry->id.book;
+ bool socket_change = book_change || last_socket != entry->id.socket;
+
+ /* If we reach the sentinel get out */
+ if (entry->id.level5) {
+ break;
+ }
+
+ if (level > 3 && drawer_change) {
+ SYSIB_GUARD(n, sizeof(SysIBTl_container));
+ p = fill_container(p, 3, drawer_id++);
+ book_id = 0;
+ }
+ if (level > 2 && book_change) {
+ SYSIB_GUARD(n, sizeof(SysIBTl_container));
+ p = fill_container(p, 2, book_id++);
+ socket_id = 0;
+ }
+ if (socket_change) {
+ SYSIB_GUARD(n, sizeof(SysIBTl_container));
+ p = fill_container(p, 1, socket_id++);
+ }
+
+ SYSIB_GUARD(n, sizeof(SysIBTl_cpu));
+ p = fill_tle_cpu(p, entry);
+ last_drawer = entry->id.drawer;
+ last_book = entry->id.book;
+ last_socket = entry->id.socket;
+ }
+
+ return n;
+}
+
+/**
+ * setup_stsi:
+ * sysib: pointer to a SysIB to be filled with SysIB_151x data
+ * level: Nested level specified by the guest
+ *
+ * Setup the SYSIB for STSI 15.1, the header as well as the description
+ * of the topology.
+ */
+static int setup_stsi(SysIB_151x *sysib, int level)
+{
+ sysib->mnest = level;
+ switch (level) {
+ case 4:
+ sysib->mag[S390_TOPOLOGY_MAG4] = current_machine->smp.drawers;
+ sysib->mag[S390_TOPOLOGY_MAG3] = current_machine->smp.books;
+ sysib->mag[S390_TOPOLOGY_MAG2] = current_machine->smp.sockets;
+ sysib->mag[S390_TOPOLOGY_MAG1] = current_machine->smp.cores;
+ break;
+ case 3:
+ sysib->mag[S390_TOPOLOGY_MAG3] = current_machine->smp.drawers *
+ current_machine->smp.books;
+ sysib->mag[S390_TOPOLOGY_MAG2] = current_machine->smp.sockets;
+ sysib->mag[S390_TOPOLOGY_MAG1] = current_machine->smp.cores;
+ break;
+ case 2:
+ sysib->mag[S390_TOPOLOGY_MAG2] = current_machine->smp.drawers *
+ current_machine->smp.books *
+ current_machine->smp.sockets;
+ sysib->mag[S390_TOPOLOGY_MAG1] = current_machine->smp.cores;
+ break;
+ }
+
+ return stsi_topology_fill_sysib(sysib->tle, level);
+}
+
+/**
+ * s390_topology_add_cpu_to_entry:
+ * @entry: Topology entry to setup
+ * @cpu: the S390CPU to add
+ *
+ * Set the core bit inside the topology mask and
+ * increments the number of cores for the socket.
+ */
+static void s390_topology_add_cpu_to_entry(S390TopologyEntry *entry,
+ S390CPU *cpu)
+{
+ set_bit(63 - (cpu->env.core_id % 64), &entry->mask);
+}
+
+/**
+ * s390_topology_from_cpu:
+ * @cpu: The S390CPU
+ *
+ * Initialize the topology id from the CPU environment.
+ */
+static s390_topology_id s390_topology_from_cpu(S390CPU *cpu)
+{
+ s390_topology_id topology_id = {0};
+
+ topology_id.drawer = cpu->env.drawer_id;
+ topology_id.book = cpu->env.book_id;
+ topology_id.socket = cpu->env.socket_id;
+ topology_id.origin = cpu->env.core_id / 64;
+ topology_id.type = S390_TOPOLOGY_CPU_IFL;
+ topology_id.dedicated = cpu->env.dedicated;
+
+ if (s390_topology.polarization == S390_CPU_POLARIZATION_VERTICAL) {
+ /*
+ * Vertical polarization with dedicated CPU implies
+ * vertical high entitlement.
+ */
+ if (topology_id.dedicated) {
+ topology_id.entitlement = S390_CPU_ENTITLEMENT_HIGH;
+ } else {
+ topology_id.entitlement = cpu->env.entitlement;
+ }
+ }
+
+ return topology_id;
+}
+
+/**
+ * s390_topology_insert:
+ * @cpu: s390CPU insert.
+ *
+ * Parse the topology list to find if the entry already
+ * exist and add the core in it.
+ * If it does not exist, allocate a new entry and insert
+ * it in the queue from lower id to greater id.
+ */
+static void s390_topology_insert(S390CPU *cpu)
+{
+ s390_topology_id id = s390_topology_from_cpu(cpu);
+ S390TopologyEntry *entry = NULL;
+ S390TopologyEntry *tmp = NULL;
+
+ QTAILQ_FOREACH(tmp, &s390_topology.list, next) {
+ if (id.id == tmp->id.id) {
+ s390_topology_add_cpu_to_entry(tmp, cpu);
+ return;
+ } else if (id.id < tmp->id.id) {
+ entry = g_malloc0(sizeof(S390TopologyEntry));
+ entry->id.id = id.id;
+ s390_topology_add_cpu_to_entry(entry, cpu);
+ QTAILQ_INSERT_BEFORE(tmp, entry, next);
+ return;
+ }
+ }
+}
+
+/**
+ * s390_topology_fill_list_sorted:
+ *
+ * Loop over all CPU and insert it at the right place
+ * inside the TLE entry list.
+ * Fill the S390Topology list with entries according to the order
+ * specified by the PoP.
+ */
+static void s390_topology_fill_list_sorted(void)
+{
+ CPUState *cs;
+
+ CPU_FOREACH(cs) {
+ s390_topology_insert(S390_CPU(cs));
+ }
+}
+
+/**
+ * s390_topology_empty_list:
+ *
+ * Clear all entries in the S390Topology list except the sentinel.
+ */
+static void s390_topology_empty_list(void)
+{
+ S390TopologyEntry *entry = NULL;
+ S390TopologyEntry *tmp = NULL;
+
+ QTAILQ_FOREACH_SAFE(entry, &s390_topology.list, next, tmp) {
+ if (!entry->id.level5) {
+ QTAILQ_REMOVE(&s390_topology.list, entry, next);
+ g_free(entry);
+ }
+ }
+}
+
+/**
+ * insert_stsi_15_1_x:
+ * cpu: the CPU doing the call for which we set CC
+ * sel2: the selector 2, containing the nested level
+ * addr: Guest logical address of the guest SysIB
+ * ar: the access register number
+ *
+ * Emulate STSI 15.1.x, that is, perform all necessary checks and
+ * fill the SYSIB.
+ * In case the topology description is too long to fit into the SYSIB,
+ * set CC=3 and abort without writing the SYSIB.
+ */
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, uint64_t addr, uint8_t ar)
+{
+ SysIB sysib = {0};
+ int length;
+
+ if (!s390_has_topology() || sel2 < 2 || sel2 > SCLP_READ_SCP_INFO_MNEST) {
+ setcc(cpu, 3);
+ return;
+ }
+
+ s390_topology_fill_list_sorted();
+
+ length = setup_stsi(&sysib.sysib_151x, sel2);
+
+ if (!length) {
+ setcc(cpu, 3);
+ return;
+ }
+
+ sysib.sysib_151x.length = cpu_to_be16(length);
+ s390_cpu_virt_mem_write(cpu, addr, ar, &sysib, length);
+ setcc(cpu, 0);
+
+ s390_topology_empty_list();
+}
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 3ac7ec9acf..5ea358cbb0 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -1919,9 +1919,12 @@ 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);
+ return 0;
default:
return 0;
}
diff --git a/target/s390x/kvm/meson.build b/target/s390x/kvm/meson.build
index aef52b6686..5daa5c6033 100644
--- a/target/s390x/kvm/meson.build
+++ b/target/s390x/kvm/meson.build
@@ -1,6 +1,7 @@

s390x_ss.add(when: 'CONFIG_KVM', if_true: files(
- 'kvm.c'
+ 'kvm.c',
+ 'cpu_topology.c'
), if_false: files(
'stubs.c'
))
--
2.31.1