Add new types of KVM stats, linear and logarithmic histogram.
Histogram are very useful for observing the value distribution
of time or size related stats.
Signed-off-by: NJing Zhang <jingzhangos@google.com>
Message-Id: <20210802165633.1866976-2-jingzhangos@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>