On 11/3/22 18:01, Pierre Morel wrote:
The guest can use the STSI instruction to get a buffer filled
with the CPU topology description.
Let us implement the STSI instruction for the basis CPU topology
level, level 2.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
include/hw/s390x/cpu-topology.h | 6 ++
target/s390x/cpu.h | 77 ++++++++++++++++++++++++
hw/s390x/cpu-topology.c | 1 -
target/s390x/cpu_topology.c | 100 ++++++++++++++++++++++++++++++++
target/s390x/kvm/kvm.c | 6 +-
target/s390x/meson.build | 1 +
6 files changed, 189 insertions(+), 2 deletions(-)
create mode 100644 target/s390x/cpu_topology.c
diff --git a/include/hw/s390x/cpu-topology.h b/include/hw/s390x/cpu-topology.h
index 4e16a2153d..6fec10e032 100644
--- a/include/hw/s390x/cpu-topology.h
+++ b/include/hw/s390x/cpu-topology.h
@@ -16,6 +16,11 @@
#define S390_TOPOLOGY_CPU_IFL 0x03
#define S390_TOPOLOGY_MAX_ORIGIN ((63 + S390_MAX_CPUS) / 64)
+#define S390_TOPOLOGY_POLARITY_HORIZONTAL 0x00
+#define S390_TOPOLOGY_POLARITY_VERTICAL_LOW 0x01
+#define S390_TOPOLOGY_POLARITY_VERTICAL_MEDIUM 0x02
+#define S390_TOPOLOGY_POLARITY_VERTICAL_HIGH 0x03
+
typedef struct S390TopoSocket {
int active_count;
uint64_t mask[S390_TOPOLOGY_MAX_ORIGIN];
@@ -26,6 +31,7 @@ struct S390Topology {
uint32_t nr_cpus;
uint32_t nr_sockets;
S390TopoSocket *socket;
+ bool topology_needed;
};
#define TYPE_S390_CPU_TOPOLOGY "s390-topology"
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index c9066b2496..69a7523146 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -567,6 +567,81 @@ typedef union SysIB {
} 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 one level, the socket 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];
+ uint8_t reserved1:5;
+ uint8_t dedicated:1;
+ uint8_t polarity:2;
+ uint8_t type;
+ uint16_t origin;
+ uint64_t mask;
+} QEMU_PACKED QEMU_ALIGNED(8) SysIBTl_cpu;
+QEMU_BUILD_BUG_ON(sizeof(SysIBTl_cpu) != 16);
+
+#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[0];
+} QEMU_PACKED QEMU_ALIGNED(8) SysIB_151x;
+QEMU_BUILD_BUG_ON(sizeof(SysIB_151x) != 16);
+
+/* Max size of a SYSIB structure is when all CPU are alone in a container */
+#define S390_TOPOLOGY_SYSIB_SIZE (sizeof(SysIB_151x) + \
+ S390_MAX_CPUS * (sizeof(SysIBTl_container) + \
+ sizeof(SysIBTl_cpu)))
+
+
/* MMU defines */
#define ASCE_ORIGIN (~0xfffULL) /* segment table origin */
#define ASCE_SUBSPACE 0x200 /* subspace group control */
@@ -845,4 +920,6 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
#include "exec/cpu-all.h"
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar);
+
#endif
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 6af41d3d7b..9fa8ca1261 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -44,7 +44,6 @@ void s390_topology_new_cpu(S390CPU *cpu)
int socket_id;
socket_id = core_id / topo->nr_cpus;
-
/*
* At the core level, each CPU is represented by a bit in a 64bit
* uint64_t which represent the presence of a CPU.
diff --git a/target/s390x/cpu_topology.c b/target/s390x/cpu_topology.c
new file mode 100644
index 0000000000..a1179d8e95
--- /dev/null
+++ b/target/s390x/cpu_topology.c
@@ -0,0 +1,100 @@
+/*
+ * QEMU S390x CPU Topology
+ *
+ * Copyright IBM Corp. 2022
+ * Author(s): Pierre Morel <pmorel@xxxxxxxxxxxxx>
+ *
+ * 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/cpu-topology.h"
+#include "hw/s390x/sclp.h"
+
+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);
+}
+
+static char *fill_tle_cpu(char *p, uint64_t mask, int origin)
+{
+ SysIBTl_cpu *tle = (SysIBTl_cpu *)p;
+
+ tle->nl = 0;
+ tle->dedicated = 1;
+ tle->polarity = S390_TOPOLOGY_POLARITY_HORIZONTAL;
+ tle->type = S390_TOPOLOGY_CPU_IFL;
+ tle->origin = cpu_to_be64(origin * 64);
+ tle->mask = cpu_to_be64(mask);
+ return p + sizeof(*tle);
+}
+
+static char *s390_top_set_level2(S390Topology *topo, char *p)
+{
+ int i, origin;
+
+ for (i = 0; i < topo->nr_sockets; i++) {
+ if (!topo->socket[i].active_count) {
+ continue;
+ }
+ p = fill_container(p, 1, i);
+ for (origin = 0; origin < S390_TOPOLOGY_MAX_ORIGIN; origin++) {
+ uint64_t mask = 0L;
+
+ mask = topo->socket[i].mask[origin];
+ if (mask) {
+ p = fill_tle_cpu(p, mask, origin);
+ }
+ }
+ }
+ return p;
+}
Why is it not possible to compute this topo information at "runtime",
when stsi is called, without maintaining state in an extra S390Topology
object ? Couldn't we loop on the CPU list to gather the topology bits
for the same result ?
It would greatly simplify the feature.
C.
+static int setup_stsi(S390CPU *cpu, SysIB_151x *sysib, int level)
+{
+ S390Topology *topo = (S390Topology *)cpu->topology;
+ char *p = sysib->tle;
+
+ sysib->mnest = level;
+ switch (level) {
+ case 2:
+ sysib->mag[S390_TOPOLOGY_MAG2] = topo->nr_sockets;
+ sysib->mag[S390_TOPOLOGY_MAG1] = topo->nr_cpus;
+ p = s390_top_set_level2(topo, p);
+ break;
+ }
+
+ return p - (char *)sysib;
+}
+
+#define S390_TOPOLOGY_MAX_MNEST 2
+
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar)
+{
+ union {
+ char place_holder[S390_TOPOLOGY_SYSIB_SIZE];
+ SysIB_151x sysib;
+ } buffer QEMU_ALIGNED(8);
+ int len;
+
+ if (s390_is_pv() || !s390_has_topology() ||
+ sel2 < 2 || sel2 > S390_TOPOLOGY_MAX_MNEST) {
+ setcc(cpu, 3);
+ return;
+ }
+
+ len = setup_stsi(cpu, &buffer.sysib, sel2);
+
+ buffer.sysib.length = cpu_to_be16(len);
+ s390_cpu_virt_mem_write(cpu, addr, ar, &buffer.sysib, len);
+ setcc(cpu, 0);
+}
+
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 3ac7ec9acf..7dc96f3663 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -51,6 +51,7 @@
#include "hw/s390x/s390-virtio-ccw.h"
#include "hw/s390x/s390-virtio-hcall.h"
#include "hw/s390x/pv.h"
+#include "hw/s390x/cpu-topology.h"
#ifndef DEBUG_KVM
#define DEBUG_KVM 0
@@ -1919,9 +1920,12 @@ 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/meson.build b/target/s390x/meson.build
index 84c1402a6a..890ccfa789 100644
--- a/target/s390x/meson.build
+++ b/target/s390x/meson.build
@@ -29,6 +29,7 @@ s390x_softmmu_ss.add(files(
'sigp.c',
'cpu-sysemu.c',
'cpu_models_sysemu.c',
+ 'cpu_topology.c',
))
s390x_user_ss = ss.source_set()
