Update 'kvm-hv-pmu.c' to add five new perf-events mapped to the five
Hostwide counters. Since these newly introduced perf events are at system
wide scope and can be read from any L1-Lpar CPU, 'kvmppc_pmu' scope and
capabilities are updated appropriately.
Also introduce two new helpers. First is kvmppc_update_l0_stats() that uses
the infrastructure introduced in previous patches to issues the
H_GUEST_GET_STATE hcall L0-PowerVM to fetch guest-state-buffer holding the
latest values of these counters which is then parsed and 'l0_stats'
variable updated.
Second helper is kvmppc_pmu_event_update() which is called from
'kvmppv_pmu' callbacks and uses kvmppc_update_l0_stats() to update
'l0_stats' and the update the 'struct perf_event's event-counter.
Some minor updates to kvmppc_pmu_{add, del, read}() to remove some debug
scaffolding code.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Athira Rajeev <atrajeev@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416162740.93143-7-vaibhav@linux.ibm.com
Implement and setup necessary structures to send a prepolulated
Guest-State-Buffer(GSB) requesting hostwide counters to L0-PowerVM and have
the returned GSB holding the values of these counters parsed. This is done
via existing GSB implementation and with the newly added support of
Hostwide elements in GSB.
The request to L0-PowerVM to return Hostwide counters is done using a
pre-allocated GSB named 'gsb_l0_stats'. To be able to populate this GSB
with the needed Guest-State-Elements (GSIDs) a instance of 'struct
kvmppc_gs_msg' named 'gsm_l0_stats' is introduced. The 'gsm_l0_stats' is
tied to an instance of 'struct kvmppc_gs_msg_ops' named 'gsb_ops_l0_stats'
which holds various callbacks to be compute the size ( hostwide_get_size()
), populate the GSB ( hostwide_fill_info() ) and
refresh ( hostwide_refresh_info() ) the contents of
'l0_stats' that holds the Hostwide counters returned from L0-PowerVM.
To protect these structures from simultaneous access a spinlock
'lock_l0_stats' has been introduced. The allocation and initialization of
the above structures is done in newly introduced kvmppc_init_hostwide() and
similarly the cleanup is performed in newly introduced
kvmppc_cleanup_hostwide().
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416162740.93143-6-vaibhav@linux.ibm.com
Introduce a new PMU named 'kvm-hv' inside a new module named 'kvm-hv-pmu'
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 enableusers to monitor active kvm-hv based guests.
The patch creates necessary scaffolding to for the new PMU callbacks and
introduces the new kernel module name 'kvm-hv-pmu' which is built with
CONFIG_KVM_BOOK3S_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>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416162740.93143-5-vaibhav@linux.ibm.com
