Messages in this thread | | | Subject | Re: [PATCH v4 05/10] KVM: arm64: Support stolen time reporting via shared structure | From | Zenghui Yu <> | Date | Tue, 3 Sep 2019 17:14:18 +0800 |
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On 2019/8/30 16:42, Steven Price wrote: > 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. > > The hypervisor allocates memory which is placed at an IPA chosen by user > space.
It seems that no allocation happens in the hypervisor code. User space will do it instead?
> 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>
Thanks, zenghui
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