> We are currently using maxcpus to calculate the omitted sockets
> but using cpus to calculate the omitted cores/threads. This makes
> cmdlines like:
> -smp cpus=8,maxcpus=16
> -smp cpus=8,cores=4,maxcpus=16
> -smp cpus=8,threads=2,maxcpus=16
> work fine but the ones like:
> -smp cpus=8,sockets=2,maxcpus=16
> -smp cpus=8,sockets=2,cores=4,maxcpus=16
> -smp cpus=8,sockets=2,threads=2,maxcpus=16
> break the sanity check.
>
> Since we require for a valid config that the product of "sockets * cores
> * threads" should equal to the maxcpus, we should uniformly use maxcpus
> to calculate their omitted values.
>
> Also the if-branch of "cpus == 0 || sockets == 0" was split into two
> branches of "cpus == 0" and "sockets == 0" so that we can clearly read
> that we are parsing the configuration with a preference on cpus over
> sockets over cores over threads.
>
> Note: change in this patch won't affect any existing working cmdlines
> but improves consistency and allows more incomplete configs to be valid.
>
> Reviewed-by: Andrew Jones <drjo...@redhat.com>
> Signed-off-by: Yanan Wang <wangyana...@huawei.com>
> ---
> hw/core/machine.c | 30 +++++++++++++++---------------
> hw/i386/pc.c | 30 +++++++++++++++---------------
> 2 files changed, 30 insertions(+), 30 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 696d9e8e47..69979c93dd 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -755,24 +755,26 @@ static void smp_parse(MachineState *ms,
> SMPConfiguration *config, Error **errp)
> }
>
> /* compute missing values, prefer sockets over cores over threads */
> - if (cpus == 0 || sockets == 0) {
> + maxcpus = maxcpus > 0 ? maxcpus : cpus;
> +
> + if (cpus == 0) {
> + sockets = sockets > 0 ? sockets : 1;
> cores = cores > 0 ? cores : 1;
> threads = threads > 0 ? threads : 1;
> - if (cpus == 0) {
> - sockets = sockets > 0 ? sockets : 1;
> - cpus = cores * threads * sockets;
> - } else {
> - maxcpus = maxcpus > 0 ? maxcpus : cpus;
> - sockets = maxcpus / (cores * threads);
> - }
> + cpus = sockets * cores * threads;
> + maxcpus = maxcpus > 0 ? maxcpus : cpus;
> + } else if (sockets == 0) {
> + cores = cores > 0 ? cores : 1;
> + threads = threads > 0 ? threads : 1;
> + sockets = maxcpus / (cores * threads);
> } else if (cores == 0) {
> threads = threads > 0 ? threads : 1;
> - cores = cpus / (sockets * threads);
> - cores = cores > 0 ? cores : 1;
> + cores = maxcpus / (sockets * threads);
> } else if (threads == 0) {
> - threads = cpus / (cores * sockets);
> - threads = threads > 0 ? threads : 1;
> - } else if (sockets * cores * threads < cpus) {
> + threads = maxcpus / (sockets * cores);
> + }
> +
> + if (sockets * cores * threads < cpus) {
> error_setg(errp, "cpu topology: "
> "sockets (%u) * cores (%u) * threads (%u) < "
> "smp_cpus (%u)",
> @@ -780,8 +782,6 @@ static void smp_parse(MachineState *ms, SMPConfiguration
> *config, Error **errp)
> return;
> }
>
> - maxcpus = maxcpus > 0 ? maxcpus : cpus;
> -
> if (maxcpus < cpus) {
> error_setg(errp, "maxcpus must be equal to or greater than smp");
> return;
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index acd31af452..a9ff9ef52c 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -725,24 +725,26 @@ static void pc_smp_parse(MachineState *ms,
> SMPConfiguration *config, Error **err
> dies = dies > 0 ? dies : 1;
>
> /* compute missing values, prefer sockets over cores over threads */
> - if (cpus == 0 || sockets == 0) {
> + maxcpus = maxcpus > 0 ? maxcpus : cpus;
> +
> + if (cpus == 0) {
> + sockets = sockets > 0 ? sockets : 1;
> cores = cores > 0 ? cores : 1;
> threads = threads > 0 ? threads : 1;
> - if (cpus == 0) {
> - sockets = sockets > 0 ? sockets : 1;
> - cpus = cores * threads * dies * sockets;
> - } else {
> - maxcpus = maxcpus > 0 ? maxcpus : cpus;
> - sockets = maxcpus / (dies * cores * threads);
> - }
> + cpus = sockets * dies * cores * threads;
> + maxcpus = maxcpus > 0 ? maxcpus : cpus;
> + } else if (sockets == 0) {
> + cores = cores > 0 ? cores : 1;
> + threads = threads > 0 ? threads : 1;
> + sockets = maxcpus / (dies * cores * threads);
> } else if (cores == 0) {
> threads = threads > 0 ? threads : 1;
> - cores = cpus / (sockets * dies * threads);
> - cores = cores > 0 ? cores : 1;
> + cores = maxcpus / (sockets * dies * threads);
> } else if (threads == 0) {
> - threads = cpus / (cores * dies * sockets);
> - threads = threads > 0 ? threads : 1;
> - } else if (sockets * dies * cores * threads < cpus) {
> + threads = maxcpus / (sockets * dies * cores);
> + }
> +
> + if (sockets * dies * cores * threads < cpus) {
> error_setg(errp, "cpu topology: "
> "sockets (%u) * dies (%u) * cores (%u) * threads (%u) < "
> "smp_cpus (%u)",
> @@ -750,8 +752,6 @@ static void pc_smp_parse(MachineState *ms,
> SMPConfiguration *config, Error **err
> return;
> }
>
> - maxcpus = maxcpus > 0 ? maxcpus : cpus;
> -
> if (maxcpus < cpus) {
> error_setg(errp, "maxcpus must be equal to or greater than smp");
> return;
Reviewed-by: Pankaj Gupta <pankaj.gu...@ionos.com>
