On Sun, May 16, 2021 at 06:32:28PM +0800, Yanan Wang wrote:
> 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 <wangyana...@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;
> ms->smp.cores = cores;
> ms->smp.threads = threads;
> }
> --
> 2.19.1
>
After reworking "[RFC PATCH v3 9/9] hw/arm/virt: Add separate -smp parsing
function for ARM machines", this should also be reworked and fully tested,
possibly using a standalone test, as as I suggested in the other review.
Thanks,
drew
