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hw/core/machine-smp: Deprecate unsupported "parameter=1" SMP configurations

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Currently, it was allowed for users to specify the unsupported
topology parameter as "1". For example, x86 PC machine doesn't
support drawer/book/cluster topology levels, but user could specify
"-smp drawers=1,books=1,clusters=1".

This is meaningless and confusing, so that the support for this kind of
configurations is marked deprecated since 9.0. And report warning
message for such case like:

qemu-system-x86_64: warning: Deprecated CPU topology (considered invalid):
                    Unsupported clusters parameter mustn't be specified as 1
qemu-system-x86_64: warning: Deprecated CPU topology (considered invalid):
                    Unsupported books parameter mustn't be specified as 1
qemu-system-x86_64: warning: Deprecated CPU topology (considered invalid):
                    Unsupported drawers parameter mustn't be specified as 1

Users have to ensure that all the topology members described with -smp
are supported by the target machine.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20240308160148.3130837-3-zhao1.liu@linux.intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
This commit is contained in:
Zhao Liu 2024-03-09 00:01:37 +08:00 committed by Philippe Mathieu-Daudé
parent 72d346f3b8
commit 54c4ea8f3a
2 changed files with 62 additions and 17 deletions
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14
docs/about/deprecated.rst
View File

@ -57,6 +57,20 @@ The ``-p`` option pretends to control the host page size. However,
it is not possible to change the host page size, and using the it is not possible to change the host page size, and using the
option only causes failures. option only causes failures.
``-smp`` (Unsupported "parameter=1" SMP configurations) (since 9.0)
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Specified CPU topology parameters must be supported by the machine.
In the SMP configuration, users should provide the CPU topology parameters that
are supported by the target machine.
However, historically it was allowed for users to specify the unsupported
topology parameter as "1", which is meaningless. So support for this kind of
configurations (e.g. -smp drawers=1,books=1,clusters=1 for x86 PC machine) is
marked deprecated since 9.0, users have to ensure that all the topology members
described with -smp are supported by the target machine.
QEMU Machine Protocol (QMP) commands QEMU Machine Protocol (QMP) commands
------------------------------------ ------------------------------------

65
hw/core/machine-smp.c
View File

@ -112,30 +112,61 @@ void machine_parse_smp_config(MachineState *ms,
/* /*
* If not supported by the machine, a topology parameter must be * If not supported by the machine, a topology parameter must be
* omitted or specified equal to 1. * omitted.
*/ */
if (!mc->smp_props.dies_supported && dies > 1) { if (!mc->smp_props.clusters_supported && config->has_clusters) {
error_setg(errp, "dies not supported by this machine's CPU topology"); if (config->clusters > 1) {
return; error_setg(errp, "clusters not supported by this "
"machine's CPU topology");
return;
} else {
/* Here clusters only equals 1 since we've checked zero case. */
warn_report("Deprecated CPU topology (considered invalid): "
"Unsupported clusters parameter mustn't be "
"specified as 1");
}
} }
if (!mc->smp_props.clusters_supported && clusters > 1) {
error_setg(errp, "clusters not supported by this machine's CPU topology");
return;
}
dies = dies > 0 ? dies : 1;
clusters = clusters > 0 ? clusters : 1; clusters = clusters > 0 ? clusters : 1;
if (!mc->smp_props.books_supported && books > 1) { if (!mc->smp_props.dies_supported && config->has_dies) {
error_setg(errp, "books not supported by this machine's CPU topology"); if (config->dies > 1) {
return; error_setg(errp, "dies not supported by this "
"machine's CPU topology");
return;
} else {
/* Here dies only equals 1 since we've checked zero case. */
warn_report("Deprecated CPU topology (considered invalid): "
"Unsupported dies parameter mustn't be "
"specified as 1");
}
}
dies = dies > 0 ? dies : 1;
if (!mc->smp_props.books_supported && config->has_books) {
if (config->books > 1) {
error_setg(errp, "books not supported by this "
"machine's CPU topology");
return;
} else {
/* Here books only equals 1 since we've checked zero case. */
warn_report("Deprecated CPU topology (considered invalid): "
"Unsupported books parameter mustn't be "
"specified as 1");
}
} }
books = books > 0 ? books : 1; books = books > 0 ? books : 1;
if (!mc->smp_props.drawers_supported && drawers > 1) { if (!mc->smp_props.drawers_supported && config->has_drawers) {
error_setg(errp, if (config->drawers > 1) {
"drawers not supported by this machine's CPU topology"); error_setg(errp, "drawers not supported by this "
return; "machine's CPU topology");
return;
} else {
/* Here drawers only equals 1 since we've checked zero case. */
warn_report("Deprecated CPU topology (considered invalid): "
"Unsupported drawers parameter mustn't be "
"specified as 1");
}
} }
drawers = drawers > 0 ? drawers : 1; drawers = drawers > 0 ? drawers : 1;