On 25/04/2023 18.14, Pierre Morel wrote:
S390 adds two new SMP levels, drawers and books to the CPU
topology.
The S390 CPU have specific topology features like dedication
and entitlement to give to the guest indications on the host
vCPUs scheduling and help the guest take the best decisions
on the scheduling of threads on the vCPUs.
Let us provide the SMP properties with books and drawers levels
and S390 CPU with dedication and entitlement,
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
...> diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 2e267fa458..42a6a40333 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -342,3 +342,15 @@
'TARGET_S390X',
'TARGET_MIPS',
'TARGET_LOONGARCH64' ] } }
+
+##
+# @CpuS390Polarization:
+#
+# An enumeration of cpu polarization that can be assumed by a virtual
+# S390 CPU
+#
+# Since: 8.1
+##
+{ 'enum': 'CpuS390Polarization',
+ 'prefix': 'S390_CPU_POLARIZATION',
+ 'data': [ 'horizontal', 'vertical' ] }
It seems like you don't need this here yet ... I think you likely could also
introduce it in a later patch instead (patch 11 seems the first one that
needs this?)
Also, would a " 'if': 'TARGET_S390X' " be possible here, too?
diff --git a/hw/core/machine-smp.c b/hw/core/machine-smp.c
index c3dab007da..77bee06304 100644
--- a/hw/core/machine-smp.c
+++ b/hw/core/machine-smp.c
@@ -30,8 +30,19 @@ static char *cpu_hierarchy_to_string(MachineState *ms)
{
MachineClass *mc = MACHINE_GET_CLASS(ms);
GString *s = g_string_new(NULL);
+ const char *multiply = " * ", *prefix = "";
- g_string_append_printf(s, "sockets (%u)", ms->smp.sockets);
+ if (mc->smp_props.drawers_supported) {
+ g_string_append_printf(s, "drawers (%u)", ms->smp.drawers);
+ prefix = multiply;
That "prefix" stuff looks complicated ... why don't you simply add the "*"
at the end of the strings:
g_string_append_printf(s, "drawers (%u) * ",
ms->smp.drawers);
?
+ }
+
+ if (mc->smp_props.books_supported) {
+ g_string_append_printf(s, "%sbooks (%u)", prefix, ms->smp.books);
+ prefix = multiply;
+ }
+
+ g_string_append_printf(s, "%ssockets (%u)", prefix, ms->smp.sockets);
... it's followed by "sockets" here anyway, so adding the " * " at the end
of the strings above should be fine.
{
MachineClass *mc = MACHINE_GET_CLASS(ms);
unsigned cpus = config->has_cpus ? config->cpus : 0;
+ unsigned drawers = config->has_drawers ? config->drawers : 0;
+ unsigned books = config->has_books ? config->books : 0;
unsigned sockets = config->has_sockets ? config->sockets : 0;
unsigned dies = config->has_dies ? config->dies : 0;
unsigned clusters = config->has_clusters ? config->clusters : 0;
@@ -85,6 +98,8 @@ void machine_parse_smp_config(MachineState *ms,
* explicit configuration like "cpus=0" is not allowed.
*/
if ((config->has_cpus && config->cpus == 0) ||
+ (config->has_drawers && config->drawers == 0) ||
+ (config->has_books && config->books == 0) ||
(config->has_sockets && config->sockets == 0) ||
(config->has_dies && config->dies == 0) ||
(config->has_clusters && config->clusters == 0) ||
@@ -111,6 +126,19 @@ void machine_parse_smp_config(MachineState *ms,
dies = dies > 0 ? dies : 1;
clusters = clusters > 0 ? clusters : 1;
+ if (!mc->smp_props.books_supported && books > 1) {
+ error_setg(errp, "books not supported by this machine's CPU topology");
+ return;
+ }
+ books = books > 0 ? books : 1;
Could be shortened to: book = books ?: 1;
+ if (!mc->smp_props.drawers_supported && drawers > 1) {
+ error_setg(errp,
+ "drawers not supported by this machine's CPU topology");
+ return;
+ }
+ drawers = drawers > 0 ? drawers : 1;
Could be shortened to: drawers = drawers ?: 1;
/* compute missing values based on the provided ones */
if (cpus == 0 && maxcpus == 0) {
sockets = sockets > 0 ? sockets : 1;
@@ -124,33 +152,41 @@ void machine_parse_smp_config(MachineState *ms,
if (sockets == 0) {
cores = cores > 0 ? cores : 1;
threads = threads > 0 ? threads : 1;
- sockets = maxcpus / (dies * clusters * cores * threads);
+ sockets = maxcpus /
+ (drawers * books * dies * clusters * cores * threads);
} else if (cores == 0) {
threads = threads > 0 ? threads : 1;
- cores = maxcpus / (sockets * dies * clusters * threads);
+ cores = maxcpus /
+ (drawers * books * sockets * dies * clusters * threads);
}
(not very important, but I wonder whether we should maybe disallow
"prefer_sockets" with drawers and books instead of updating the calculation
here - since prefer_sockets should only occur on old machine types)
} else {
/* prefer cores over sockets since 6.2 */
if (cores == 0) {
sockets = sockets > 0 ? sockets : 1;
threads = threads > 0 ? threads : 1;
- cores = maxcpus / (sockets * dies * clusters * threads);
+ cores = maxcpus /
+ (drawers * books * sockets * dies * clusters * threads);
} else if (sockets == 0) {
threads = threads > 0 ? threads : 1;
- sockets = maxcpus / (dies * clusters * cores * threads);
+ sockets = maxcpus /
+ (drawers * books * dies * clusters * cores * threads);
}
}
Thomas
