Re: [PATCH 0/3] hw/arm/virt: Introduce kvm-steal-time

[Peter Maydell]

On Sat, 11 Jul 2020 at 11:10, Andrew Jones <drjones@redhat.com> wrote:
>
> KVM supports the ability to publish the amount of time that VCPUs
> were runnable, but not running due to other host threads running
> instead, to the guest. The guest scheduler may use that information
> when making decisions and the guest may expose it to its userspace
> (Linux publishes this information in /proc/stat). This feature is
> called "steal time" as it represents the amount of time stolen from
> a guest by scheduling out its VCPUs. To enable this feature KVM
> userspace must provide a memory region that will be used to publish
> the information to the guest. The memory region is typical migratable
> region. The GPA of the region is given to KVM through a VCPU device
> ioctl interface. This feature is only available for 64-bit hosts
> running 64-bit guests.
>
> This series provides the QEMU support of this feature. It will
> be enabled by default for 5.1 machine types and later, but may
> be disabled with a new CPU property "kvm-steal-time".

Just a note that this has missed 5.1, but I'll review it at
some point for 5.2.

thanks
-- PMM