On Tue, May 21, 2019 at 12:50:54AM +0800, Like Xu wrote:
> For PC target, users could configure the number of dies per one package
> via command line with this patch, such as "-smp dies=2,cores=4".
>
> A new pc-specified pc_smp_parse() is introduced and to keep the interface
> consistent, refactoring legacy smp_parse() to __smp_parse() is necessary.
>
> The parsing rules of new cpu-topology model obey the same restrictions/logic
> as the legacy socket/core/thread model especially on missing values computing.
>
> Signed-off-by: Like Xu <like...@linux.intel.com>
> ---
> qemu-options.hx | 17 +++++-----
> vl.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 97 insertions(+), 9 deletions(-)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 5daa5a8fb0..7fad5b50ff 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -138,25 +138,26 @@ no incompatible TCG features have been enabled (e.g.
> icount/replay).
> ETEXI
>
> DEF("smp", HAS_ARG, QEMU_OPTION_smp,
> - "-smp
> [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
> + "-smp
> [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n"
> " set the number of CPUs to 'n' [default=1]\n"
> " maxcpus= maximum number of total cpus, including\n"
> " offline CPUs for hotplug, etc\n"
> - " cores= number of CPU cores on one socket\n"
> + " cores= number of CPU cores on one socket (for PC, it's
> on one die)\n"
> " threads= number of threads on one CPU core\n"
> + " dies= number of CPU dies on one socket (for PC only)\n"
> " sockets= number of discrete sockets in the system\n",
> QEMU_ARCH_ALL)
> STEXI
> -@item -smp
> [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
> +@item -smp
> [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
> @findex -smp
> Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
> CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
> to 4.
> -For the PC target, the number of @var{cores} per socket, the number
> -of @var{threads} per cores and the total number of @var{sockets} can be
> -specified. Missing values will be computed. If any on the three values is
> -given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
> -specifies the maximum number of hotpluggable CPUs.
> +For the PC target, the number of @var{cores} per die, the number of
> @var{threads}
> +per cores, the number of @var{dies} per packages and the total number of
> +@var{sockets} can be specified. Missing values will be computed.
> +If any on the three values is given, the total number of CPUs @var{n} can be
> omitted.
> +@var{maxcpus} specifies the maximum number of hotpluggable CPUs.
> ETEXI
>
> DEF("numa", HAS_ARG, QEMU_OPTION_numa,
> diff --git a/vl.c b/vl.c
> index 8d92e2d209..66b577f447 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -63,6 +63,7 @@ int main(int argc, char **argv)
> #include "sysemu/watchdog.h"
> #include "hw/firmware/smbios.h"
> #include "hw/acpi/acpi.h"
> +#include "hw/i386/pc.h"
> #include "hw/xen/xen.h"
> #include "hw/qdev.h"
> #include "hw/loader.h"
> @@ -1248,6 +1249,9 @@ static QemuOptsList qemu_smp_opts = {
> }, {
> .name = "sockets",
> .type = QEMU_OPT_NUMBER,
> + }, {
> + .name = "dies",
> + .type = QEMU_OPT_NUMBER,
> }, {
> .name = "cores",
> .type = QEMU_OPT_NUMBER,
> @@ -1262,7 +1266,7 @@ static QemuOptsList qemu_smp_opts = {
> },
> };
>
> -static void smp_parse(QemuOpts *opts)
> +static void __smp_parse(QemuOpts *opts)
> {
> if (opts) {
> unsigned cpus = qemu_opt_get_number(opts, "cpus", 0);
> @@ -1334,6 +1338,89 @@ static void smp_parse(QemuOpts *opts)
> }
> }
>
> +static void pc_smp_parse(QemuOpts *opts)
> +{
> + PCMachineState *pcms = (PCMachineState *)
> + object_dynamic_cast(OBJECT(current_machine), TYPE_PC_MACHINE);
> +
> + unsigned cpus = qemu_opt_get_number(opts, "cpus", 0);
> + unsigned sockets = qemu_opt_get_number(opts, "sockets", 0);
> + unsigned dies = qemu_opt_get_number(opts, "dies", 1);
> + unsigned cores = qemu_opt_get_number(opts, "cores", 0);
> + unsigned threads = qemu_opt_get_number(opts, "threads", 0);
> +
> + /* compute missing values, prefer sockets over cores over threads */
> + if (cpus == 0 || sockets == 0) {
> + cores = cores > 0 ? cores : 1;
> + threads = threads > 0 ? threads : 1;
> + if (cpus == 0) {
> + sockets = sockets > 0 ? sockets : 1;
> + cpus = cores * threads * dies * sockets;
> + } else {
> + current_machine->smp.max_cpus =
> + qemu_opt_get_number(opts, "maxcpus", cpus);
> + sockets = current_machine->smp.max_cpus / (cores * threads *
> dies);
> + }
> + } else if (cores == 0) {
> + threads = threads > 0 ? threads : 1;
> + cores = cpus / (sockets * dies * threads);
> + cores = cores > 0 ? cores : 1;
> + } else if (threads == 0) {
> + threads = cpus / (cores * dies * sockets);
> + threads = threads > 0 ? threads : 1;
> + } else if (sockets * dies * cores * threads < cpus) {
> + error_report("cpu topology: "
> + "sockets (%u) * dies (%u) * cores (%u) * threads
> (%u) < "
> + "smp_cpus (%u)",
> + sockets, dies, cores, threads, cpus);
> + exit(1);
> + }
> +
> + current_machine->smp.max_cpus =
> + qemu_opt_get_number(opts, "maxcpus", cpus);
> +
> + if (current_machine->smp.max_cpus < cpus) {
> + error_report("maxcpus must be equal to or greater than smp");
> + exit(1);
> + }
> +
> + if (sockets * dies * cores * threads > current_machine->smp.max_cpus) {
> + error_report("cpu topology: "
> + "sockets (%u) * dies (%u) * cores (%u) * threads
> (%u) > "
> + "maxcpus (%u)",
> + sockets, dies, cores, threads,
> + current_machine->smp.max_cpus);
> + exit(1);
> + }
> +
> + if (sockets * dies * cores * threads != current_machine->smp.max_cpus) {
> + warn_report("Invalid CPU topology deprecated: "
> + "sockets (%u) * dies (%u) * cores (%u) * threads (%u) "
> + "!= maxcpus (%u)",
> + sockets, dies, cores, threads,
> + current_machine->smp.max_cpus);
> + }
> +
> + current_machine->smp.cpus = cpus;
> + current_machine->smp.cores = cores;
> + current_machine->smp.threads = threads;
> + pcms->smp_dies = dies;
> +
> + if (current_machine->smp.cpus > 1) {
> + Error *blocker = NULL;
> + error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "smp");
> + replay_add_blocker(blocker);
> + }
> +}
> +
> +static void smp_parse(QemuOpts *opts)
> +{
> + if (object_dynamic_cast(OBJECT(current_machine), TYPE_PC_MACHINE))
> + pc_smp_parse(opts);
This is not exactly what I meant when I suggested creating a
pc_smp_parse() function.
The idea was to place the PC-specific function inside
hw/i386/pc.c, and have a MachineClass::smp_parse function pointer
that machine types could override.
The existing generic smp_parse() code, on the other hand, could
be moved to hw/core/machine.c, and be the default implementation
of MachineClass::smp_parse.
Suggestion: If you first create a copy of smp_parse() in one
patch, and then add CPU die support in another patch, it will be
much easier to review the changes you added to the pc_smp_parse()
code.
> + else
> + __smp_parse(opts);
> +}
> +
> static void realtime_init(void)
> {
> if (enable_mlock) {
> --
> 2.21.0
>
>
--
Eduardo
