On 11/7/22 14:20, Janis Schoetterl-Glausch wrote:
On Fri, 2022-10-28 at 12:00 +0200, Pierre Morel wrote:
On 10/27/22 22:42, Janis Schoetterl-Glausch wrote:
On Wed, 2022-10-12 at 18:21 +0200, 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 | 3 +
target/s390x/cpu.h | 48 ++++++++++++++
hw/s390x/cpu-topology.c | 8 ++-
target/s390x/cpu_topology.c | 109 ++++++++++++++++++++++++++++++++
target/s390x/kvm/kvm.c | 6 +-
target/s390x/meson.build | 1 +
6 files changed, 172 insertions(+), 3 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 66c171d0bc..61c11db017 100644
--- a/include/hw/s390x/cpu-topology.h
+++ b/include/hw/s390x/cpu-topology.h
@@ -13,6 +13,8 @@
#include "hw/qdev-core.h"
#include "qom/object.h"
+#define S390_TOPOLOGY_POLARITY_H 0x00
+
typedef struct S390TopoContainer {
int active_count;
} S390TopoContainer;
@@ -29,6 +31,7 @@ struct S390Topology {
S390TopoContainer *socket;
S390TopoTLE *tle;
MachineState *ms;
+ QemuMutex topo_mutex;
};
#define TYPE_S390_CPU_TOPOLOGY "s390-topology"
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 7d6d01325b..d604aa9c78 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
[...]
+
+/* Maxi size of a SYSIB structure is when all CPU are alone in a container */
Max or Maximum.
+#define S390_TOPOLOGY_SYSIB_SIZE (sizeof(SysIB_151x) + \
+ S390_MAX_CPUS * (sizeof(SysIBTl_container) + \
+ sizeof(SysIBTl_cpu)))
Currently this is 16+248*3*8 == 5968 and will grow with books, drawer support to
16+248*5*8 == 9936 ...
[...]
+
+void insert_stsi_15_1_x(S390CPU *cpu, int sel2, __u64 addr, uint8_t ar)
+{
+ uint64_t page[S390_TOPOLOGY_SYSIB_SIZE / sizeof(uint64_t)] = {};
... so calling this page is a bit misleading. Also why not make it a char[]?
And maybe use a union for type punning.
OK, what about:
union {
char place_holder[S390_TOPOLOGY_SYSIB_SIZE];
SysIB_151x sysib;
} buffer QEMU_ALIGNED(8);
I don't think you need the QEMU_ALIGNED since SysIB_151x already has it. Not that it hurts to be
explicit. If you declared the tle member as uint64_t[], you should get the correct alignment
automatically and can then drop the explicit one.
I find the explicit statement better. Why make it non explicit?
Btw, [] seems to be preferred over [0], at least there is a commit doing a conversion:
f7795e4096 ("misc: Replace zero-length arrays with flexible array member (automatic)")
OK
+ SysIB_151x *sysib = (SysIB_151x *) page;
+ int len;
+
+ if (s390_is_pv() || !s390_has_topology() ||
+ sel2 < 2 || sel2 > S390_TOPOLOGY_MAX_MNEST) {
+ setcc(cpu, 3);
+ return;
+ }
+
+ len = setup_stsi(sysib, sel2);
This should now be memory safe, but might be larger than 4k,
the maximum size of the SYSIB. I guess you want to set cc code 3
in this case and return.
I do not find why the SYSIB can not be larger than 4k.
Can you point me to this restriction?
Says so at the top of the description of STSI:
The SYSIB is 4K bytes and must begin at a 4 K-byte
boundary; otherwise, a specification exception may
be recognized.
Right, I guess I can not read.
So I will return CC=3 in case the length is greater than 4K
thanks,
Regards,
Pierre
--
Pierre Morel
IBM Lab Boeblingen
