On 03/09/2019 10:14, Zenghui Yu wrote: > 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? Ah, yes I should update the commit message. User space does now allocate the memory. Thanks for spotting that. Steve >> 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@xxxxxxx> > > Thanks, > zenghui >
