From: Qemu-devel
[mailto:qemu-devel-bounces+salil.mehta=huawei.com@nongnu.org] On Behalf Of
Yanan Wang
Sent: Sunday, May 16, 2021 11:32 AM
To: Peter Maydell <peter.maydell@linaro.org>; Paolo Bonzini
<pbonzini@redhat.com>; Andrew Jones <drjones@redhat.com>; Michael S . Tsirkin
<mst@redhat.com>; Igor Mammedov <imammedo@redhat.com>; Shannon Zhao
<shannon.zhaosl@gmail.com>; qemu-devel@nongnu.org; qemu-arm@nongnu.org
Cc: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com>; Philippe
Mathieu-Daudé <philmd@redhat.com>; wangyanan (Y) <wangyanan55@huawei.com>;
Zengtao (B) <prime.zeng@hisilicon.com>; Wanghaibin (D)
<wanghaibin.wang@huawei.com>; yuzenghui <yuzenghui@huawei.com>; yangyicong
<yangyicong@huawei.com>; zhukeqian <zhukeqian1@huawei.com>
Subject: [RFC PATCH v3 4/4] hw/arm/virt: Parse -smp cluster parameter in
virt_smp_parse
There is a separate function virt_smp_parse() in hw/virt/arm.c used
to parse cpu topology for the ARM machines. So add parsing of -smp
cluster parameter in it, then total number of logical cpus will be
calculated like: max_cpus = sockets * clusters * cores * threads.
Note, we will assume multi-cluster in one socket is not supported
and default the value of clusters to 1, if it's not explicitly
specified in -smp cmdline.
Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
hw/arm/virt.c | 32 ++++++++++++++++++--------------
1 file changed, 18 insertions(+), 14 deletions(-)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 7de822e491..678d5ef36c 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2642,8 +2642,8 @@ static int virt_kvm_type(MachineState *ms, const char
*type_str)
* with the -smp cmdlines when parsing them.
*
* We require that at least one of cpus or maxcpus must be provided.
- * Threads will default to 1 if not provided. Sockets and cores must
- * be either both provided or both not.
+ * Clusters and threads will default to 1 if they are not provided.
+ * Sockets and cores must be either both provided or both not.
*
* Note, if neither sockets nor cores are specified, we will calculate
* all the missing values just like smp_parse() does, but will disable
@@ -2652,15 +2652,18 @@ static int virt_kvm_type(MachineState *ms, const char
*type_str)
static void virt_smp_parse(MachineState *ms, QemuOpts *opts)
{
VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(ms);
+ VirtMachineState *vms = VIRT_MACHINE(ms);
if (opts) {
unsigned cpus = qemu_opt_get_number(opts, "cpus", 0);
unsigned maxcpus = qemu_opt_get_number(opts, "maxcpus", 0);
unsigned sockets = qemu_opt_get_number(opts, "sockets", 0);
+ unsigned clusters = qemu_opt_get_number(opts, "clusters", 0);
unsigned cores = qemu_opt_get_number(opts, "cores", 0);
unsigned threads = qemu_opt_get_number(opts, "threads", 0);
- /* Default threads to 1 if not provided */
+ /* Default clusters and threads to 1 if not provided */
+ clusters = clusters > 0 ? clusters : 1;
threads = threads > 0 ? threads : 1;
if (cpus == 0 && maxcpus == 0) {
@@ -2676,13 +2679,13 @@ static void virt_smp_parse(MachineState *ms, QemuOpts
*opts)
cores = 1;
if (cpus == 0) {
sockets = 1;
- cpus = sockets * cores * threads;
+ cpus = sockets * clusters * cores * threads;
} else {
maxcpus = maxcpus > 0 ? maxcpus : cpus;
- sockets = maxcpus / (cores * threads);
+ sockets = maxcpus / (clusters * cores * threads);
}
} else if (sockets > 0 && cores > 0) {
- cpus = cpus > 0 ? cpus : sockets * cores * threads;
+ cpus = cpus > 0 ? cpus : sockets * clusters * cores * threads;
maxcpus = maxcpus > 0 ? maxcpus : cpus;
} else {
error_report("sockets and cores must be both provided "
@@ -2695,25 +2698,26 @@ static void virt_smp_parse(MachineState *ms, QemuOpts
*opts)
exit(1);
}
- if (sockets * cores * threads < cpus) {
+ if (sockets * clusters * cores * threads < cpus) {
error_report("cpu topology: "
- "sockets (%u) * cores (%u) * threads (%u) < "
- "smp_cpus (%u)",
- sockets, cores, threads, cpus);
+ "sockets (%u) * clusters (%u) * cores (%u) * "
+ "threads (%u) < smp_cpus (%u)",
+ sockets, clusters, cores, threads, cpus);
exit(1);
}
- if (sockets * cores * threads != maxcpus) {
+ if (sockets * clusters * cores * threads != maxcpus) {
error_report("cpu topology: "
- "sockets (%u) * cores (%u) * threads (%u) "
- "!= maxcpus (%u)",
- sockets, cores, threads, maxcpus);
+ "sockets (%u) * clusters (%u) * cores (%u) * "
+ "threads (%u) != maxcpus (%u)",
+ sockets, clusters, cores, threads, maxcpus);
exit(1);
}
ms->smp.cpus = cpus;
ms->smp.max_cpus = maxcpus;
ms->smp.sockets = sockets;
+ vms->smp_clusters = clusters;