On 12/6/22 10:48, Janis Schoetterl-Glausch wrote:
On Tue, 2022-11-29 at 18:42 +0100, Pierre Morel wrote:
The guest uses the STSI instruction to get information on the
CPU topology.
Let us implement the STSI instruction for the basis CPU topology
level, level 2.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
target/s390x/cpu.h | 77 +++++++++++++++
hw/s390x/s390-virtio-ccw.c | 12 +--
target/s390x/cpu_topology.c | 186 ++++++++++++++++++++++++++++++++++++
target/s390x/kvm/kvm.c | 6 +-
target/s390x/meson.build | 1 +
5 files changed, 274 insertions(+), 8 deletions(-)
create mode 100644 target/s390x/cpu_topology.c
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 7d6d01325b..dd878ac916 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
[...]
+/* 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];
AFAIK [] is preferred over [0].
grr, yes, I think I have been already told so :)
+} QEMU_PACKED QEMU_ALIGNED(8) SysIB_151x;
+QEMU_BUILD_BUG_ON(sizeof(SysIB_151x) != 16);
[...]
+/*
+ * s390_topology_add_cpu:
+ * @topo: pointer to the topology
+ * @cpu : pointer to the new CPU
+ *
+ * The topology pointed by S390CPU, gives us the CPU topology
+ * established by the -smp QEMU aruments.
+ * The core-id is used to calculate the position of the CPU inside
+ * the topology:
+ * - the socket, container TLE, containing the CPU, we have one socket
+ * for every num_cores cores.
+ * - the CPU TLE inside the socket, we have potentionly up to 4 CPU TLE
+ * in a container TLE with the assumption that all CPU are identical
+ * with the same polarity and entitlement because we have maximum 256
+ * CPUs and each TLE can hold up to 64 identical CPUs.
+ * - the bit in the 64 bit CPU TLE core mask
+ */
+static void s390_topology_add_cpu(S390Topology *topo, S390CPU *cpu)
+{
+ int core_id = cpu->env.core_id;
+ int bit, origin;
+ int socket_id;
+
+ cpu->machine_data = topo;
+ socket_id = core_id / topo->num_cores;
+ /*
+ * At the core level, each CPU is represented by a bit in a 64bit
+ * uint64_t which represent the presence of a CPU.
+ * The firmware assume that all CPU in a CPU TLE have the same
+ * type, polarization and are all dedicated or shared.
+ * In that case the origin variable represents the offset of the first
+ * CPU in the CPU container.
+ * More than 64 CPUs per socket are represented in several CPU containers
+ * inside the socket container.
+ * The only reason to have several S390TopologyCores inside a socket is
+ * to have more than 64 CPUs.
+ * In that case the origin variable represents the offset of the first CPU
+ * in the CPU container. More than 64 CPUs per socket are represented in
+ * several CPU containers inside the socket container.
+ */
This comment still contains redundant sentences.
Did you have a look at my suggestion in v10 patch 1?
Yes, I had, and sorry, I forgot to report here inside the patch 11.
I will take it, thanks for it.
+ bit = core_id;
+ origin = bit / 64;
+ bit %= 64;
+ bit = 63 - bit;
+
+ topo->socket[socket_id].active_count++;
+ set_bit(bit, &topo->socket[socket_id].mask[origin]);
+}
+
+/*
+ * s390_prepare_topology:
+ * @s390ms : pointer to the S390CcwMachite State
+ *
+ * Calls s390_topology_add_cpu to organize the topology
+ * inside the topology device before writing the SYSIB.
+ *
+ * The topology is currently fixed on boot and do not change
does not change
yes, thanks
regards,
Pierre
--
Pierre Morel
IBM Lab Boeblingen
