• Steven Price's avatar
    arm64: Retrieve stolen time as paravirtualized guest · e0685fa2
    Steven Price authored
    Enable paravirtualization features when running under a hypervisor
    supporting the PV_TIME_ST hypercall.
    
    For each (v)CPU, we ask the hypervisor for the location of a shared
    page which the hypervisor will use to report stolen time to us. We set
    pv_time_ops to the stolen time function which simply reads the stolen
    value from the shared page for a VCPU. We guarantee single-copy
    atomicity using READ_ONCE which means we can also read the stolen
    time for another VCPU than the currently running one while it is
    potentially being updated by the hypervisor.
    Signed-off-by: default avatarSteven Price <steven.price@arm.com>
    Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
    e0685fa2
time.c 1.47 KB