diff options
| author | Reiji Watanabe <reijiw@google.com> | 2023-10-21 00:40:42 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-10-25 01:59:29 +0300 |
| commit | 427733579744ef22ee6d0da9907560d79d937458 (patch) | |
| tree | 5adb3b554a7332cdbf78c9429d2ce5ed97a583e5 /arch/arm64/kvm/pmu-emul.c | |
| parent | 1616ca6f3c10723c1b60ae44724212fae88f502d (diff) | |
| download | linux-427733579744ef22ee6d0da9907560d79d937458.tar.xz | |
KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handler
Future changes to KVM's sysreg emulation will rely on having a valid PMU
instance to determine the number of implemented counters (PMCR_EL0.N).
This is earlier than when userspace is expected to modify the vPMU
device attributes, where the default is selected today.
Select the default PMU when handling KVM_ARM_VCPU_INIT such that it is
available in time for sysreg emulation.
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/20231020214053.2144305-3-rananta@google.com
[Oliver: rewrite changelog]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kvm/pmu-emul.c')
| -rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index fb9817bdfeb5..1eb02765dd14 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -717,10 +717,9 @@ static struct arm_pmu *kvm_pmu_probe_armpmu(void) * It is still necessary to get a valid cpu, though, to probe for the * default PMU instance as userspace is not required to specify a PMU * type. In order to uphold the preexisting behavior KVM selects the - * PMU instance for the core where the first call to the - * KVM_ARM_VCPU_PMU_V3_CTRL attribute group occurs. A dependent use case - * would be a user with disdain of all things big.LITTLE that affines - * the VMM to a particular cluster of cores. + * PMU instance for the core during vcpu init. A dependent use + * case would be a user with disdain of all things big.LITTLE that + * affines the VMM to a particular cluster of cores. * * In any case, userspace should just do the sane thing and use the UAPI * to select a PMU type directly. But, be wary of the baggage being @@ -893,7 +892,7 @@ static void kvm_arm_set_pmu(struct kvm *kvm, struct arm_pmu *arm_pmu) * where vCPUs can be scheduled on any core but the guest * counters could stop working. */ -static int kvm_arm_set_default_pmu(struct kvm *kvm) +int kvm_arm_set_default_pmu(struct kvm *kvm) { struct arm_pmu *arm_pmu = kvm_pmu_probe_armpmu(); @@ -946,13 +945,6 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) if (vcpu->arch.pmu.created) return -EBUSY; - if (!kvm->arch.arm_pmu) { - int ret = kvm_arm_set_default_pmu(kvm); - - if (ret) - return ret; - } - switch (attr->attr) { case KVM_ARM_VCPU_PMU_V3_IRQ: { int __user *uaddr = (int __user *)(long)attr->addr; |