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| author | Steven Price <steven.price@arm.com> | 2019-10-21 16:28:18 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2019-10-21 19:20:28 +0100 |
| commit | 8564d6372a7d8a6d440441b8ed8020f97f744450 (patch) | |
| tree | 1ec19f1184aafb3ccfe9574f760115e170b5cb16 /virt/kvm/arm/hypercalls.c | |
| parent | cac0f1b7285eaaf9a186c618c3a7304d82ed5493 (diff) | |
| download | linux-8564d6372a7d8a6d440441b8ed8020f97f744450.tar.gz linux-8564d6372a7d8a6d440441b8ed8020f97f744450.tar.bz2 linux-8564d6372a7d8a6d440441b8ed8020f97f744450.zip | |
KVM: arm64: Support stolen time reporting via shared structure
Implement the service call for configuring a shared structure between a
VCPU and the hypervisor in which the hypervisor can write the time
stolen from the VCPU's execution time by other tasks on the host.
User space allocates memory which is placed at an IPA also chosen by user
space. The hypervisor then updates the shared structure using
kvm_put_guest() to ensure single copy atomicity of the 64-bit value
reporting the stolen time in nanoseconds.
Whenever stolen time is enabled by the guest, the stolen time counter is
reset.
The stolen time itself is retrieved from the sched_info structure
maintained by the Linux scheduler code. We enable SCHEDSTATS when
selecting KVM Kconfig to ensure this value is meaningful.
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'virt/kvm/arm/hypercalls.c')
| -rw-r--r-- | virt/kvm/arm/hypercalls.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/virt/kvm/arm/hypercalls.c b/virt/kvm/arm/hypercalls.c index 97ea8b133e77..550dfa3e53cd 100644 --- a/virt/kvm/arm/hypercalls.c +++ b/virt/kvm/arm/hypercalls.c @@ -14,6 +14,7 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) u32 func_id = smccc_get_function(vcpu); long val = SMCCC_RET_NOT_SUPPORTED; u32 feature; + gpa_t gpa; switch (func_id) { case ARM_SMCCC_VERSION_FUNC_ID: @@ -56,6 +57,11 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) case ARM_SMCCC_HV_PV_TIME_FEATURES: val = kvm_hypercall_pv_features(vcpu); break; + case ARM_SMCCC_HV_PV_TIME_ST: + gpa = kvm_init_stolen_time(vcpu); + if (gpa != GPA_INVALID) + val = gpa; + break; default: return kvm_psci_call(vcpu); } |