linux/include/kvm
Raghavendra Rao Ananta 4d20debf9c KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU
The number of PMU event counters is indicated in PMCR_EL0.N.
For a vCPU with PMUv3 configured, the value is set to the same
value as the current PE on every vCPU reset.  Unless the vCPU is
pinned to PEs that has the PMU associated to the guest from the
initial vCPU reset, the value might be different from the PMU's
PMCR_EL0.N on heterogeneous PMU systems.

Fix this by setting the vCPU's PMCR_EL0.N to the PMU's PMCR_EL0.N
value. Track the PMCR_EL0.N per guest, as only one PMU can be set
for the guest (PMCR_EL0.N must be the same for all vCPUs of the
guest), and it is convenient for updating the value.

To achieve this, the patch introduces a helper,
kvm_arm_pmu_get_max_counters(), that reads the maximum number of
counters from the arm_pmu associated to the VM. Make the function
global as upcoming patches will be interested to know the value
while setting the PMCR.N of the guest from userspace.

KVM does not yet support userspace modifying PMCR_EL0.N.
The following patch will add support for that.

Reviewed-by: Sebastian Ott <sebott@redhat.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Link: https://lore.kernel.org/r/20231020214053.2144305-5-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24 22:59:30 +00:00
..
arm_arch_timer.h Merge branch kvm-arm64/timer-vm-offsets into kvmarm-master/next 2023-04-21 09:36:40 +01:00
arm_hypercalls.h KVM: arm64: Introduce support for userspace SMCCC filtering 2023-04-05 12:07:41 +01:00
arm_pmu.h KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU 2023-10-24 22:59:30 +00:00
arm_psci.h KVM: arm64: Factor out firmware register handling from psci.c 2022-05-03 14:48:54 +01:00
arm_vgic.h KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemption 2023-07-13 22:23:34 +00:00
iodev.h KVM: destruct kvm_io_device while unregistering it from kvm_io_bus 2023-06-13 14:18:09 -07:00