KVM dirty ring is a new interface to pass over dirty bits from kernel to the
userspace. Instead of using a bitmap for each memory region, the dirty ring
contains an array of dirtied GPAs to fetch (in the form of offset in slots).
For each vcpu there will be one dirty ring that binds to it.
kvm_dirty_ring_reap() is the major function to collect dirty rings. It can be
called either by a standalone reaper thread that runs in the background,
collecting dirty pages for the whole VM. It can also be called directly by any
thread that has BQL taken.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-11-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
b4420f198d