A gentle ping ...
Will this patch be picked up soon for 6.1 or is there anything else to
tweak?
Thanks,
Yanan
On 2021/7/23 17:57, Yanan Wang wrote:
In the SMP configuration, we should either specify a topology
parameter with a reasonable value (equal to or greater than 1)
or just leave it omitted and QEMU will calculate its value.
Configurations which explicitly specify the topology parameters
as zero like "sockets=0" are meaningless, so disallow them.
However, the commit 1e63fe685804d
(machine: pass QAPI struct to mc->smp_parse) has documented that
'0' has the same semantics as omitting a parameter in the qapi
comment for SMPConfiguration. So this patch fixes the doc and
also adds the corresponding sanity check.
Reviewed-by: Cornelia Huck <coh...@redhat.com>
Reviewed-by: Andrew Jones <drjo...@redhat.com>
Reviewed-by: Daniel P. Berrange <berra...@redhat.com>
Tested-by: Daniel P. Berrange <berra...@redhat.com>
Suggested-by: Andrew Jones <drjo...@redhat.com>
Signed-off-by: Yanan Wang <wangyana...@huawei.com>
---
hw/core/machine.c | 14 ++++++++++++++
qapi/machine.json | 6 +++---
qemu-options.hx | 12 +++++++-----
3 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 775add0795..e1533dfc47 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -829,6 +829,20 @@ static void machine_set_smp(Object *obj, Visitor *v, const
char *name,
return;
}
+ /*
+ * The CPU topology parameters must be specified greater than zero or
+ * just omitted, explicit configuration like "cpus=0" is not allowed.
+ */
+ if ((config->has_cpus && config->cpus == 0) ||
+ (config->has_sockets && config->sockets == 0) ||
+ (config->has_dies && config->dies == 0) ||
+ (config->has_cores && config->cores == 0) ||
+ (config->has_threads && config->threads == 0) ||
+ (config->has_maxcpus && config->maxcpus == 0)) {
+ error_setg(errp, "CPU topology parameters must be greater than zero");
+ goto out_free;
+ }
+
mc->smp_parse(ms, config, errp);
if (errp) {
goto out_free;
diff --git a/qapi/machine.json b/qapi/machine.json
index c3210ee1fb..9272cb3cf8 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -1288,8 +1288,8 @@
##
# @SMPConfiguration:
#
-# Schema for CPU topology configuration. "0" or a missing value lets
-# QEMU figure out a suitable value based on the ones that are provided.
+# Schema for CPU topology configuration. A missing value lets QEMU
+# figure out a suitable value based on the ones that are provided.
#
# @cpus: number of virtual CPUs in the virtual machine
#
@@ -1297,7 +1297,7 @@
#
# @dies: number of dies per socket in the CPU topology
#
-# @cores: number of cores per thread in the CPU topology
+# @cores: number of cores per die in the CPU topology
#
# @threads: number of threads per core in the CPU topology
#
diff --git a/qemu-options.hx b/qemu-options.hx
index 99ed5ec5f1..e077aa80bf 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -223,11 +223,13 @@ SRST
of computing the CPU maximum count.
Either the initial CPU count, or at least one of the topology parameters
- must be specified. Values for any omitted parameters will be computed
- from those which are given. Historically preference was given to the
- coarsest topology parameters when computing missing values (ie sockets
- preferred over cores, which were preferred over threads), however, this
- behaviour is considered liable to change.
+ must be specified. The specified parameters must be greater than zero,
+ explicit configuration like "cpus=0" is not allowed. Values for any
+ omitted parameters will be computed from those which are given.
+ Historically preference was given to the coarsest topology parameters
+ when computing missing values (ie sockets preferred over cores, which
+ were preferred over threads), however, this behaviour is considered
+ liable to change.
ERST
DEF("numa", HAS_ARG, QEMU_OPTION_numa,
