| Message ID | 20201109030452.2197-4-fangying1@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hw/arm/virt: Introduce cpu and cache topology support | expand |
> From: fangying > Sent: Monday, November 9, 2020 3:05 AM > To: peter.maydell@linaro.org > Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; drjones@redhat.com; > imammedo@redhat.com; shannon.zhaosl@gmail.com; alistair.francis@wdc.com; > Zhanghailiang <zhang.zhanghailiang@huawei.com>; Salil Mehta > <salil.mehta@huawei.com> > Subject: [RFC PATCH v3 03/13] hw/arm/virt: Replace smp_parse with one that > prefers cores > > From: Andrew Jones <drjones@redhat.com> > > The virt machine type has never used the CPU topology parameters, other > than number of online CPUs and max CPUs. When choosing how to allocate > those CPUs the default has been to assume cores. In preparation for > using the other CPU topology parameters let's use an smp_parse that > prefers cores over sockets. We can also enforce the topology matches > max_cpus check because we have no legacy to preserve. Hi Andrew, I am wondering if we need to take care of other levels of processor hierarchy as well in ARM64 like 'clusters'/'Dies'? Thanks > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > hw/arm/virt.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 76 insertions(+) > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > index ea24b576c6..ba902b53ba 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -78,6 +78,8 @@ > #include "hw/virtio/virtio-iommu.h" > #include "hw/char/pl011.h" > #include "qemu/guest-random.h" > +#include "qapi/qmp/qerror.h" > +#include "sysemu/replay.h" > > #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \ > static void virt_##major##_##minor##_class_init(ObjectClass *oc, \ > @@ -2444,6 +2446,79 @@ static int virt_kvm_type(MachineState *ms, const char > *type_str) > return requested_pa_size > 40 ? requested_pa_size : 0; > } > > +/* > + * Unlike smp_parse() in hw/core/machine.c, we prefer cores over sockets, > + * e.g. '-smp 8' creates 1 socket with 8 cores. Whereas '-smp 8' with > + * hw/core/machine.c's smp_parse() creates 8 sockets, each with 1 core. > + * Additionally, we can enforce the topology matches max_cpus check, > + * because we have no legacy to preserve. > + */ > +static void virt_smp_parse(MachineState *ms, QemuOpts *opts) > +{ > + if (opts) { > + unsigned cpus = qemu_opt_get_number(opts, "cpus", 0); > + unsigned sockets = qemu_opt_get_number(opts, "sockets", 0); > + unsigned cores = qemu_opt_get_number(opts, "cores", 0); > + unsigned threads = qemu_opt_get_number(opts, "threads", 0); > + > + /* > + * Compute missing values; prefer cores over sockets and > + * sockets over threads. > + */ > + if (cpus == 0 || cores == 0) { > + sockets = sockets > 0 ? sockets : 1; > + threads = threads > 0 ? threads : 1; > + if (cpus == 0) { > + cores = cores > 0 ? cores : 1; > + cpus = cores * threads * sockets; > + } else { > + ms->smp.max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > + cores = ms->smp.max_cpus / (sockets * threads); > + } > + } else if (sockets == 0) { > + threads = threads > 0 ? threads : 1; > + sockets = cpus / (cores * threads); > + sockets = sockets > 0 ? sockets : 1; > + } else if (threads == 0) { > + threads = cpus / (cores * sockets); > + threads = threads > 0 ? threads : 1; > + } else if (sockets * cores * threads < cpus) { > + error_report("cpu topology: " > + "sockets (%u) * cores (%u) * threads (%u) < " > + "smp_cpus (%u)", > + sockets, cores, threads, cpus); > + exit(1); > + } > + > + ms->smp.max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > + > + if (ms->smp.max_cpus < cpus) { > + error_report("maxcpus must be equal to or greater than smp"); > + exit(1); > + } > + > + if (sockets * cores * threads != ms->smp.max_cpus) { > + error_report("cpu topology: " > + "sockets (%u) * cores (%u) * threads (%u)" > + "!= maxcpus (%u)", > + sockets, cores, threads, > + ms->smp.max_cpus); > + exit(1); > + } > + > + ms->smp.cpus = cpus; > + ms->smp.cores = cores; > + ms->smp.threads = threads; > + ms->smp.sockets = sockets; > + } > + > + if (ms->smp.cpus > 1) { > + Error *blocker = NULL; > + error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "smp"); > + replay_add_blocker(blocker); > + } > +} > + > static void virt_machine_class_init(ObjectClass *oc, void *data) > { > MachineClass *mc = MACHINE_CLASS(oc); > @@ -2469,6 +2544,7 @@ static void virt_machine_class_init(ObjectClass *oc, void > *data) > mc->cpu_index_to_instance_props = virt_cpu_index_to_props; > mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15"); > mc->get_default_cpu_node_id = virt_get_default_cpu_node_id; > + mc->smp_parse = virt_smp_parse; > mc->kvm_type = virt_kvm_type; > assert(!mc->get_hotplug_handler); > mc->get_hotplug_handler = virt_machine_get_hotplug_handler; > -- > 2.23.0
On Mon, Nov 09, 2020 at 11:01:48AM +0000, Salil Mehta wrote: > > From: fangying > > Sent: Monday, November 9, 2020 3:05 AM > > To: peter.maydell@linaro.org > > Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; drjones@redhat.com; > > imammedo@redhat.com; shannon.zhaosl@gmail.com; alistair.francis@wdc.com; > > Zhanghailiang <zhang.zhanghailiang@huawei.com>; Salil Mehta > > <salil.mehta@huawei.com> > > Subject: [RFC PATCH v3 03/13] hw/arm/virt: Replace smp_parse with one that > > prefers cores > > > > From: Andrew Jones <drjones@redhat.com> > > > > The virt machine type has never used the CPU topology parameters, other > > than number of online CPUs and max CPUs. When choosing how to allocate > > those CPUs the default has been to assume cores. In preparation for > > using the other CPU topology parameters let's use an smp_parse that > > prefers cores over sockets. We can also enforce the topology matches > > max_cpus check because we have no legacy to preserve. > > > Hi Andrew, > I am wondering if we need to take care of other levels of processor > hierarchy as well in ARM64 like 'clusters'/'Dies'? I don't know, but so far in Linux only x86 considers dies. Also, Linux doesn't define the concept of a cluster in its arch-neutral cpu topology API. With that in mind, I think we should just focus on sockets, cores, and threads until we have a guest OS that can be used to test other levels. Thanks, drew > > Thanks > > > > > > Signed-off-by: Andrew Jones <drjones@redhat.com> > > --- > > hw/arm/virt.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 76 insertions(+) > > > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > > index ea24b576c6..ba902b53ba 100644 > > --- a/hw/arm/virt.c > > +++ b/hw/arm/virt.c > > @@ -78,6 +78,8 @@ > > #include "hw/virtio/virtio-iommu.h" > > #include "hw/char/pl011.h" > > #include "qemu/guest-random.h" > > +#include "qapi/qmp/qerror.h" > > +#include "sysemu/replay.h" > > > > #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \ > > static void virt_##major##_##minor##_class_init(ObjectClass *oc, \ > > @@ -2444,6 +2446,79 @@ static int virt_kvm_type(MachineState *ms, const char > > *type_str) > > return requested_pa_size > 40 ? requested_pa_size : 0; > > } > > > > +/* > > + * Unlike smp_parse() in hw/core/machine.c, we prefer cores over sockets, > > + * e.g. '-smp 8' creates 1 socket with 8 cores. Whereas '-smp 8' with > > + * hw/core/machine.c's smp_parse() creates 8 sockets, each with 1 core. > > + * Additionally, we can enforce the topology matches max_cpus check, > > + * because we have no legacy to preserve. > > + */ > > +static void virt_smp_parse(MachineState *ms, QemuOpts *opts) > > +{ > > + if (opts) { > > + unsigned cpus = qemu_opt_get_number(opts, "cpus", 0); > > + unsigned sockets = qemu_opt_get_number(opts, "sockets", 0); > > + unsigned cores = qemu_opt_get_number(opts, "cores", 0); > > + unsigned threads = qemu_opt_get_number(opts, "threads", 0); > > + > > + /* > > + * Compute missing values; prefer cores over sockets and > > + * sockets over threads. > > + */ > > + if (cpus == 0 || cores == 0) { > > + sockets = sockets > 0 ? sockets : 1; > > + threads = threads > 0 ? threads : 1; > > + if (cpus == 0) { > > + cores = cores > 0 ? cores : 1; > > + cpus = cores * threads * sockets; > > + } else { > > + ms->smp.max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > > + cores = ms->smp.max_cpus / (sockets * threads); > > + } > > + } else if (sockets == 0) { > > + threads = threads > 0 ? threads : 1; > > + sockets = cpus / (cores * threads); > > + sockets = sockets > 0 ? sockets : 1; > > + } else if (threads == 0) { > > + threads = cpus / (cores * sockets); > > + threads = threads > 0 ? threads : 1; > > + } else if (sockets * cores * threads < cpus) { > > + error_report("cpu topology: " > > + "sockets (%u) * cores (%u) * threads (%u) < " > > + "smp_cpus (%u)", > > + sockets, cores, threads, cpus); > > + exit(1); > > + } > > + > > + ms->smp.max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > > + > > + if (ms->smp.max_cpus < cpus) { > > + error_report("maxcpus must be equal to or greater than smp"); > > + exit(1); > > + } > > + > > + if (sockets * cores * threads != ms->smp.max_cpus) { > > + error_report("cpu topology: " > > + "sockets (%u) * cores (%u) * threads (%u)" > > + "!= maxcpus (%u)", > > + sockets, cores, threads, > > + ms->smp.max_cpus); > > + exit(1); > > + } > > + > > + ms->smp.cpus = cpus; > > + ms->smp.cores = cores; > > + ms->smp.threads = threads; > > + ms->smp.sockets = sockets; > > + } > > + > > + if (ms->smp.cpus > 1) { > > + Error *blocker = NULL; > > + error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "smp"); > > + replay_add_blocker(blocker); > > + } > > +} > > + > > static void virt_machine_class_init(ObjectClass *oc, void *data) > > { > > MachineClass *mc = MACHINE_CLASS(oc); > > @@ -2469,6 +2544,7 @@ static void virt_machine_class_init(ObjectClass *oc, void > > *data) > > mc->cpu_index_to_instance_props = virt_cpu_index_to_props; > > mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15"); > > mc->get_default_cpu_node_id = virt_get_default_cpu_node_id; > > + mc->smp_parse = virt_smp_parse; > > mc->kvm_type = virt_kvm_type; > > assert(!mc->get_hotplug_handler); > > mc->get_hotplug_handler = virt_machine_get_hotplug_handler; > > -- > > 2.23.0 > >
diff --git a/hw/arm/virt.c b/hw/arm/virt.c index ea24b576c6..ba902b53ba 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -78,6 +78,8 @@ #include "hw/virtio/virtio-iommu.h" #include "hw/char/pl011.h" #include "qemu/guest-random.h" +#include "qapi/qmp/qerror.h" +#include "sysemu/replay.h" #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \ static void virt_##major##_##minor##_class_init(ObjectClass *oc, \ @@ -2444,6 +2446,79 @@ static int virt_kvm_type(MachineState *ms, const char *type_str) return requested_pa_size > 40 ? requested_pa_size : 0; } +/* + * Unlike smp_parse() in hw/core/machine.c, we prefer cores over sockets, + * e.g. '-smp 8' creates 1 socket with 8 cores. Whereas '-smp 8' with + * hw/core/machine.c's smp_parse() creates 8 sockets, each with 1 core. + * Additionally, we can enforce the topology matches max_cpus check, + * because we have no legacy to preserve. + */ +static void virt_smp_parse(MachineState *ms, QemuOpts *opts) +{ + if (opts) { + unsigned cpus = qemu_opt_get_number(opts, "cpus", 0); + unsigned sockets = qemu_opt_get_number(opts, "sockets", 0); + unsigned cores = qemu_opt_get_number(opts, "cores", 0); + unsigned threads = qemu_opt_get_number(opts, "threads", 0); + + /* + * Compute missing values; prefer cores over sockets and + * sockets over threads. + */ + if (cpus == 0 || cores == 0) { + sockets = sockets > 0 ? sockets : 1; + threads = threads > 0 ? threads : 1; + if (cpus == 0) { + cores = cores > 0 ? cores : 1; + cpus = cores * threads * sockets; + } else { + ms->smp.max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); + cores = ms->smp.max_cpus / (sockets * threads); + } + } else if (sockets == 0) { + threads = threads > 0 ? threads : 1; + sockets = cpus / (cores * threads); + sockets = sockets > 0 ? sockets : 1; + } else if (threads == 0) { + threads = cpus / (cores * sockets); + threads = threads > 0 ? threads : 1; + } else if (sockets * cores * threads < cpus) { + error_report("cpu topology: " + "sockets (%u) * cores (%u) * threads (%u) < " + "smp_cpus (%u)", + sockets, cores, threads, cpus); + exit(1); + } + + ms->smp.max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); + + if (ms->smp.max_cpus < cpus) { + error_report("maxcpus must be equal to or greater than smp"); + exit(1); + } + + if (sockets * cores * threads != ms->smp.max_cpus) { + error_report("cpu topology: " + "sockets (%u) * cores (%u) * threads (%u)" + "!= maxcpus (%u)", + sockets, cores, threads, + ms->smp.max_cpus); + exit(1); + } + + ms->smp.cpus = cpus; + ms->smp.cores = cores; + ms->smp.threads = threads; + ms->smp.sockets = sockets; + } + + if (ms->smp.cpus > 1) { + Error *blocker = NULL; + error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "smp"); + replay_add_blocker(blocker); + } +} + static void virt_machine_class_init(ObjectClass *oc, void *data) { MachineClass *mc = MACHINE_CLASS(oc); @@ -2469,6 +2544,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data) mc->cpu_index_to_instance_props = virt_cpu_index_to_props; mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15"); mc->get_default_cpu_node_id = virt_get_default_cpu_node_id; + mc->smp_parse = virt_smp_parse; mc->kvm_type = virt_kvm_type; assert(!mc->get_hotplug_handler); mc->get_hotplug_handler = virt_machine_get_hotplug_handler;