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| author | Marc Zyngier <maz@kernel.org> | 2022-02-08 17:54:41 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-02-08 17:54:41 +0000 |
| commit | 00e6dae00e3dcb4dd54e1d62e295fd997a0cec28 (patch) | |
| tree | d4a91abad3c1e46f5fa40692371834c0ec564156 /Documentation/virt | |
| parent | c30185412daf353e6bcc61cd50ee7b7eadf42d1e (diff) | |
| parent | 583cda1b0e7d5d49db5fc15db623166310e36bf6 (diff) | |
Merge branch kvm-arm64/pmu-bl into kvmarm-master/next
* kvm-arm64/pmu-bl:
: .
: Improve PMU support on heterogeneous systems, courtesy of Alexandru Elisei
: .
KVM: arm64: Refuse to run VCPU if the PMU doesn't match the physical CPU
KVM: arm64: Add KVM_ARM_VCPU_PMU_V3_SET_PMU attribute
KVM: arm64: Keep a list of probed PMUs
KVM: arm64: Keep a per-VM pointer to the default PMU
perf: Fix wrong name in comment for struct perf_cpu_context
KVM: arm64: Do not change the PMU event filter after a VCPU has run
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'Documentation/virt')
| -rw-r--r-- | Documentation/virt/kvm/devices/vcpu.rst | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst index 60a29972d3f1..260db203a1e2 100644 --- a/Documentation/virt/kvm/devices/vcpu.rst +++ b/Documentation/virt/kvm/devices/vcpu.rst @@ -70,7 +70,7 @@ irqchip. -ENODEV PMUv3 not supported or GIC not initialized -ENXIO PMUv3 not properly configured or in-kernel irqchip not configured as required prior to calling this attribute - -EBUSY PMUv3 already initialized + -EBUSY PMUv3 already initialized or a VCPU has already run -EINVAL Invalid filter range ======= ====================================================== @@ -104,6 +104,38 @@ hardware event. Filtering event 0x1E (CHAIN) has no effect either, as it isn't strictly speaking an event. Filtering the cycle counter is possible using event 0x11 (CPU_CYCLES). +1.4 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_SET_PMU +------------------------------------------ + +:Parameters: in kvm_device_attr.addr the address to an int representing the PMU + identifier. + +:Returns: + + ======= ==================================================== + -EBUSY PMUv3 already initialized, a VCPU has already run or + an event filter has already been set + -EFAULT Error accessing the PMU identifier + -ENXIO PMU not found + -ENODEV PMUv3 not supported or GIC not initialized + -ENOMEM Could not allocate memory + ======= ==================================================== + +Request that the VCPU uses the specified hardware PMU when creating guest events +for the purpose of PMU emulation. The PMU identifier can be read from the "type" +file for the desired PMU instance under /sys/devices (or, equivalent, +/sys/bus/even_source). This attribute is particularly useful on heterogeneous +systems where there are at least two CPU PMUs on the system. The PMU that is set +for one VCPU will be used by all the other VCPUs. It isn't possible to set a PMU +if a PMU event filter is already present. + +Note that KVM will not make any attempts to run the VCPU on the physical CPUs +associated with the PMU specified by this attribute. This is entirely left to +userspace. However, attempting to run the VCPU on a physical CPU not supported +by the PMU will fail and KVM_RUN will return with +exit_reason = KVM_EXIT_FAIL_ENTRY and populate the fail_entry struct by setting +hardare_entry_failure_reason field to KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED and +the cpu field to the processor id. 2. GROUP: KVM_ARM_VCPU_TIMER_CTRL ================================= |