| Message ID | 20250123120749.90505-5-vaibhav@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | kvm powerpc/book3s-hv: Expose Hostwide counters as perf-events | expand |
> On 23 Jan 2025, at 5:37 PM, Vaibhav Jain <vaibhav@linux.ibm.com> wrote: > > Introduce a new PMU named 'kvm-hv' to report Book3s kvm-hv specific > performance counters. This will expose KVM-HV specific performance > attributes to user-space via kernel's PMU infrastructure and would enable > users to monitor active kvm-hv based guests. > > The patch creates necessary scaffolding to for the new PMU callbacks and > introduces two new exports kvmppc_{,un}register_pmu() that are called from > kvm-hv init and exit function to perform initialize and cleanup for the > 'kvm-hv' PMU. The patch doesn't introduce any perf-events yet, which will > be introduced in later patches > > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> > > --- > Changelog > > v2->v3: > * Fixed a build warning reported by kernel build robot. > Link: > https://lore.kernel.org/oe-kbuild-all/202501171030.3x0gqW8G-lkp@intel.com > > v1->v2: > * Fixed an issue of kvm-hv not loading on baremetal kvm [Gautam] > --- > arch/powerpc/include/asm/kvm_book3s.h | 20 ++++ > arch/powerpc/kvm/Makefile | 6 ++ > arch/powerpc/kvm/book3s_hv.c | 9 ++ > arch/powerpc/kvm/book3s_hv_pmu.c | 133 ++++++++++++++++++++++++++ > 4 files changed, 168 insertions(+) > create mode 100644 arch/powerpc/kvm/book3s_hv_pmu.c > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h > index e1ff291ba891..7a7854c65ebb 100644 > --- a/arch/powerpc/include/asm/kvm_book3s.h > +++ b/arch/powerpc/include/asm/kvm_book3s.h > @@ -348,6 +348,26 @@ static inline bool kvmhv_is_nestedv1(void) > > #endif > > +/* kvm-ppc pmu registration */ > +#if IS_ENABLED(CONFIG_KVM_BOOK3S_64_HV) > +#ifdef CONFIG_PERF_EVENTS > +int kvmppc_register_pmu(void); > +void kvmppc_unregister_pmu(void); > + > +#else > + > +static inline int kvmppc_register_pmu(void) > +{ > + return 0; > +} > + > +static inline void kvmppc_unregister_pmu(void) > +{ > + /* do nothing */ > +} > +#endif /* CONFIG_PERF_EVENTS */ > +#endif /* CONFIG_KVM_BOOK3S_64_HV */ > + > int __kvmhv_nestedv2_reload_ptregs(struct kvm_vcpu *vcpu, struct pt_regs *regs); > int __kvmhv_nestedv2_mark_dirty_ptregs(struct kvm_vcpu *vcpu, struct pt_regs *regs); > int __kvmhv_nestedv2_mark_dirty(struct kvm_vcpu *vcpu, u16 iden); > diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile > index 4bd9d1230869..7645307ff277 100644 > --- a/arch/powerpc/kvm/Makefile > +++ b/arch/powerpc/kvm/Makefile > @@ -92,6 +92,12 @@ kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \ > $(kvm-book3s_64-builtin-tm-objs-y) \ > $(kvm-book3s_64-builtin-xics-objs-y) > > +# enable kvm_hv perf events > +ifdef CONFIG_PERF_EVENTS > +kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \ > + book3s_hv_pmu.o > +endif > + > obj-$(CONFIG_GUEST_STATE_BUFFER_TEST) += test-guest-state-buffer.o > endif > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 25429905ae90..6365b8126574 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -6662,6 +6662,14 @@ static int kvmppc_book3s_init_hv(void) > return r; > } > > + r = kvmppc_register_pmu(); > + if (r == -EOPNOTSUPP) { > + pr_info("KVM-HV: PMU not supported %d\n", r); > + } else if (r) { > + pr_err("KVM-HV: Unable to register PMUs %d\n", r); > + goto err; > + } > + > kvm_ops_hv.owner = THIS_MODULE; > kvmppc_hv_ops = &kvm_ops_hv; > > @@ -6676,6 +6684,7 @@ static int kvmppc_book3s_init_hv(void) > > static void kvmppc_book3s_exit_hv(void) > { > + kvmppc_unregister_pmu(); > kvmppc_uvmem_free(); > kvmppc_free_host_rm_ops(); > if (kvmppc_radix_possible()) > diff --git a/arch/powerpc/kvm/book3s_hv_pmu.c b/arch/powerpc/kvm/book3s_hv_pmu.c > new file mode 100644 > index 000000000000..8c6ed30b7654 > --- /dev/null > +++ b/arch/powerpc/kvm/book3s_hv_pmu.c > @@ -0,0 +1,133 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Description: PMUs specific to running nested KVM-HV guests > + * on Book3S processors (specifically POWER9 and later). > + */ > + > +#define pr_fmt(fmt) "kvmppc-pmu: " fmt Hi Vaibhav All PMU specific code is under “arch/powerpc/perf in the kernel source. Here since we are introducing a kvm-hv specific PMU, can we please have it in arch/powerpc/perf ? Thanks Athira > + > +#include "asm-generic/local64.h" > +#include <linux/kernel.h> > +#include <linux/errno.h> > +#include <linux/ratelimit.h> > +#include <linux/kvm_host.h> > +#include <linux/gfp_types.h> > +#include <linux/pgtable.h> > +#include <linux/perf_event.h> > +#include <linux/spinlock_types.h> > +#include <linux/spinlock.h> > + > +#include <asm/types.h> > +#include <asm/kvm_ppc.h> > +#include <asm/kvm_book3s.h> > +#include <asm/mmu.h> > +#include <asm/pgalloc.h> > +#include <asm/pte-walk.h> > +#include <asm/reg.h> > +#include <asm/plpar_wrappers.h> > +#include <asm/firmware.h> > + > +enum kvmppc_pmu_eventid { > + KVMPPC_EVENT_MAX, > +}; > + > +static struct attribute *kvmppc_pmu_events_attr[] = { > + NULL, > +}; > + > +static const struct attribute_group kvmppc_pmu_events_group = { > + .name = "events", > + .attrs = kvmppc_pmu_events_attr, > +}; > + > +PMU_FORMAT_ATTR(event, "config:0"); > +static struct attribute *kvmppc_pmu_format_attr[] = { > + &format_attr_event.attr, > + NULL, > +}; > + > +static struct attribute_group kvmppc_pmu_format_group = { > + .name = "format", > + .attrs = kvmppc_pmu_format_attr, > +}; > + > +static const struct attribute_group *kvmppc_pmu_attr_groups[] = { > + &kvmppc_pmu_events_group, > + &kvmppc_pmu_format_group, > + NULL, > +}; > + > +static int kvmppc_pmu_event_init(struct perf_event *event) > +{ > + unsigned int config = event->attr.config; > + > + pr_debug("%s: Event(%p) id=%llu cpu=%x on_cpu=%x config=%u", > + __func__, event, event->id, event->cpu, > + event->oncpu, config); > + > + if (event->attr.type != event->pmu->type) > + return -ENOENT; > + > + if (config >= KVMPPC_EVENT_MAX) > + return -EINVAL; > + > + local64_set(&event->hw.prev_count, 0); > + local64_set(&event->count, 0); > + > + return 0; > +} > + > +static void kvmppc_pmu_del(struct perf_event *event, int flags) > +{ > +} > + > +static int kvmppc_pmu_add(struct perf_event *event, int flags) > +{ > + return 0; > +} > + > +static void kvmppc_pmu_read(struct perf_event *event) > +{ > +} > + > +/* L1 wide counters PMU */ > +static struct pmu kvmppc_pmu = { > + .task_ctx_nr = perf_sw_context, > + .name = "kvm-hv", > + .event_init = kvmppc_pmu_event_init, > + .add = kvmppc_pmu_add, > + .del = kvmppc_pmu_del, > + .read = kvmppc_pmu_read, > + .attr_groups = kvmppc_pmu_attr_groups, > + .type = -1, > +}; > + > +int kvmppc_register_pmu(void) > +{ > + int rc = -EOPNOTSUPP; > + > + /* only support events for nestedv2 right now */ > + if (kvmhv_is_nestedv2()) { > + /* Setup done now register the PMU */ > + pr_info("Registering kvm-hv pmu"); > + > + /* Register only if we arent already registered */ > + rc = (kvmppc_pmu.type == -1) ? > + perf_pmu_register(&kvmppc_pmu, kvmppc_pmu.name, > + -1) : 0; > + } > + > + return rc; > +} > +EXPORT_SYMBOL_GPL(kvmppc_register_pmu); > + > +void kvmppc_unregister_pmu(void) > +{ > + if (kvmhv_is_nestedv2()) { > + if (kvmppc_pmu.type != -1) > + perf_pmu_unregister(&kvmppc_pmu); > + > + pr_info("kvmhv_pmu unregistered.\n"); > + } > +} > +EXPORT_SYMBOL_GPL(kvmppc_unregister_pmu); > -- > 2.48.1 > > >
Hi Athira, Thanks for reviewing this patch series. My responses to your review comment inline below: Athira Rajeev <atrajeev@linux.vnet.ibm.com> writes: >> On 23 Jan 2025, at 5:37 PM, Vaibhav Jain <vaibhav@linux.ibm.com> wrote: >> >> Introduce a new PMU named 'kvm-hv' to report Book3s kvm-hv specific <snip> > > Hi Vaibhav > > All PMU specific code is under “arch/powerpc/perf in the kernel source. Here since we are introducing a kvm-hv specific PMU, can we please have it in arch/powerpc/perf ? Is it common convention to put PMU specific code in arch/powerpc/perf across ppc achitecture variants ? If its there can you please mention the reasons behind it. Also the code for this PMU, will be part of kvm-hv kernel module as it utilizes the functionality implemented there. Moving this PMU code to arch/powerpc/perf will need this to be converted in yet another new kernel module, adding a dependency to kvm-hv module and exporting a bunch of functionality from kvm-hv. Which looks bit messy to me <snip>
On 1/27/25 1:06 PM, Vaibhav Jain wrote: > Hi Athira, > > Thanks for reviewing this patch series. My responses to your review > comment inline below: > > > Athira Rajeev <atrajeev@linux.vnet.ibm.com> writes: > >>> On 23 Jan 2025, at 5:37 PM, Vaibhav Jain <vaibhav@linux.ibm.com> wrote: >>> >>> Introduce a new PMU named 'kvm-hv' to report Book3s kvm-hv specific > <snip> >> >> Hi Vaibhav >> >> All PMU specific code is under “arch/powerpc/perf in the kernel source. Here since we are introducing a kvm-hv specific PMU, can we please have it in arch/powerpc/perf ? > > Is it common convention to put PMU specific code in > arch/powerpc/perf across ppc achitecture variants ? If its there can you > please mention the reasons behind it. > My concern is about fragmentation. Would prefer to have the pmu code under perf folder. Secondly, we did handle module case for vpa-pmu. Maddy > Also the code for this PMU, will be part of kvm-hv kernel module as it > utilizes the functionality implemented there. Moving this PMU code to > arch/powerpc/perf will need this to be converted in yet another new > kernel module, adding a dependency to kvm-hv module and exporting a > bunch of functionality from kvm-hv. Which looks bit messy to me > > <snip> >
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index e1ff291ba891..7a7854c65ebb 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -348,6 +348,26 @@ static inline bool kvmhv_is_nestedv1(void) #endif +/* kvm-ppc pmu registration */ +#if IS_ENABLED(CONFIG_KVM_BOOK3S_64_HV) +#ifdef CONFIG_PERF_EVENTS +int kvmppc_register_pmu(void); +void kvmppc_unregister_pmu(void); + +#else + +static inline int kvmppc_register_pmu(void) +{ + return 0; +} + +static inline void kvmppc_unregister_pmu(void) +{ + /* do nothing */ +} +#endif /* CONFIG_PERF_EVENTS */ +#endif /* CONFIG_KVM_BOOK3S_64_HV */ + int __kvmhv_nestedv2_reload_ptregs(struct kvm_vcpu *vcpu, struct pt_regs *regs); int __kvmhv_nestedv2_mark_dirty_ptregs(struct kvm_vcpu *vcpu, struct pt_regs *regs); int __kvmhv_nestedv2_mark_dirty(struct kvm_vcpu *vcpu, u16 iden); diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile index 4bd9d1230869..7645307ff277 100644 --- a/arch/powerpc/kvm/Makefile +++ b/arch/powerpc/kvm/Makefile @@ -92,6 +92,12 @@ kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \ $(kvm-book3s_64-builtin-tm-objs-y) \ $(kvm-book3s_64-builtin-xics-objs-y) +# enable kvm_hv perf events +ifdef CONFIG_PERF_EVENTS +kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \ + book3s_hv_pmu.o +endif + obj-$(CONFIG_GUEST_STATE_BUFFER_TEST) += test-guest-state-buffer.o endif diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 25429905ae90..6365b8126574 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -6662,6 +6662,14 @@ static int kvmppc_book3s_init_hv(void) return r; } + r = kvmppc_register_pmu(); + if (r == -EOPNOTSUPP) { + pr_info("KVM-HV: PMU not supported %d\n", r); + } else if (r) { + pr_err("KVM-HV: Unable to register PMUs %d\n", r); + goto err; + } + kvm_ops_hv.owner = THIS_MODULE; kvmppc_hv_ops = &kvm_ops_hv; @@ -6676,6 +6684,7 @@ static int kvmppc_book3s_init_hv(void) static void kvmppc_book3s_exit_hv(void) { + kvmppc_unregister_pmu(); kvmppc_uvmem_free(); kvmppc_free_host_rm_ops(); if (kvmppc_radix_possible()) diff --git a/arch/powerpc/kvm/book3s_hv_pmu.c b/arch/powerpc/kvm/book3s_hv_pmu.c new file mode 100644 index 000000000000..8c6ed30b7654 --- /dev/null +++ b/arch/powerpc/kvm/book3s_hv_pmu.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Description: PMUs specific to running nested KVM-HV guests + * on Book3S processors (specifically POWER9 and later). + */ + +#define pr_fmt(fmt) "kvmppc-pmu: " fmt + +#include "asm-generic/local64.h" +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/ratelimit.h> +#include <linux/kvm_host.h> +#include <linux/gfp_types.h> +#include <linux/pgtable.h> +#include <linux/perf_event.h> +#include <linux/spinlock_types.h> +#include <linux/spinlock.h> + +#include <asm/types.h> +#include <asm/kvm_ppc.h> +#include <asm/kvm_book3s.h> +#include <asm/mmu.h> +#include <asm/pgalloc.h> +#include <asm/pte-walk.h> +#include <asm/reg.h> +#include <asm/plpar_wrappers.h> +#include <asm/firmware.h> + +enum kvmppc_pmu_eventid { + KVMPPC_EVENT_MAX, +}; + +static struct attribute *kvmppc_pmu_events_attr[] = { + NULL, +}; + +static const struct attribute_group kvmppc_pmu_events_group = { + .name = "events", + .attrs = kvmppc_pmu_events_attr, +}; + +PMU_FORMAT_ATTR(event, "config:0"); +static struct attribute *kvmppc_pmu_format_attr[] = { + &format_attr_event.attr, + NULL, +}; + +static struct attribute_group kvmppc_pmu_format_group = { + .name = "format", + .attrs = kvmppc_pmu_format_attr, +}; + +static const struct attribute_group *kvmppc_pmu_attr_groups[] = { + &kvmppc_pmu_events_group, + &kvmppc_pmu_format_group, + NULL, +}; + +static int kvmppc_pmu_event_init(struct perf_event *event) +{ + unsigned int config = event->attr.config; + + pr_debug("%s: Event(%p) id=%llu cpu=%x on_cpu=%x config=%u", + __func__, event, event->id, event->cpu, + event->oncpu, config); + + if (event->attr.type != event->pmu->type) + return -ENOENT; + + if (config >= KVMPPC_EVENT_MAX) + return -EINVAL; + + local64_set(&event->hw.prev_count, 0); + local64_set(&event->count, 0); + + return 0; +} + +static void kvmppc_pmu_del(struct perf_event *event, int flags) +{ +} + +static int kvmppc_pmu_add(struct perf_event *event, int flags) +{ + return 0; +} + +static void kvmppc_pmu_read(struct perf_event *event) +{ +} + +/* L1 wide counters PMU */ +static struct pmu kvmppc_pmu = { + .task_ctx_nr = perf_sw_context, + .name = "kvm-hv", + .event_init = kvmppc_pmu_event_init, + .add = kvmppc_pmu_add, + .del = kvmppc_pmu_del, + .read = kvmppc_pmu_read, + .attr_groups = kvmppc_pmu_attr_groups, + .type = -1, +}; + +int kvmppc_register_pmu(void) +{ + int rc = -EOPNOTSUPP; + + /* only support events for nestedv2 right now */ + if (kvmhv_is_nestedv2()) { + /* Setup done now register the PMU */ + pr_info("Registering kvm-hv pmu"); + + /* Register only if we arent already registered */ + rc = (kvmppc_pmu.type == -1) ? + perf_pmu_register(&kvmppc_pmu, kvmppc_pmu.name, + -1) : 0; + } + + return rc; +} +EXPORT_SYMBOL_GPL(kvmppc_register_pmu); + +void kvmppc_unregister_pmu(void) +{ + if (kvmhv_is_nestedv2()) { + if (kvmppc_pmu.type != -1) + perf_pmu_unregister(&kvmppc_pmu); + + pr_info("kvmhv_pmu unregistered.\n"); + } +} +EXPORT_SYMBOL_GPL(kvmppc_unregister_pmu);
Introduce a new PMU named 'kvm-hv' to report Book3s kvm-hv specific performance counters. This will expose KVM-HV specific performance attributes to user-space via kernel's PMU infrastructure and would enable users to monitor active kvm-hv based guests. The patch creates necessary scaffolding to for the new PMU callbacks and introduces two new exports kvmppc_{,un}register_pmu() that are called from kvm-hv init and exit function to perform initialize and cleanup for the 'kvm-hv' PMU. The patch doesn't introduce any perf-events yet, which will be introduced in later patches Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> --- Changelog v2->v3: * Fixed a build warning reported by kernel build robot. Link: https://lore.kernel.org/oe-kbuild-all/202501171030.3x0gqW8G-lkp@intel.com v1->v2: * Fixed an issue of kvm-hv not loading on baremetal kvm [Gautam] --- arch/powerpc/include/asm/kvm_book3s.h | 20 ++++ arch/powerpc/kvm/Makefile | 6 ++ arch/powerpc/kvm/book3s_hv.c | 9 ++ arch/powerpc/kvm/book3s_hv_pmu.c | 133 ++++++++++++++++++++++++++ 4 files changed, 168 insertions(+) create mode 100644 arch/powerpc/kvm/book3s_hv_pmu.c