qemu/migration/migration.h

9  * This work is licensed under the terms of the GNU GPL, version 2.  See
51  * 1<<6=64 pages -> 256K chunk when page size is 4K.  This gives us
57  * 1<<18=256K pages -> 1G chunk when page size is 4K.  This is the
62  * 1<<31=2G pages -> 8T chunk when page size is 4K.  This should be
67 /* This is an abstraction of a "temp huge page" for postcopy's purpose */
70      * This points to a temporary huge page as a buffer for UFFDIO_COPY.  It's
75      * This points to the host page we're going to install for this temp page.
81     /* Whether this page contains all zeros */
101      * parallel with this event.
116     /* Set this when we want the fault thread to quit */
135      * This is calculated when the src requests to enable postcopy but before
143      * When postcopy_qemufile_dst is properly setup, this sem is posted.
144      * One can wait on this semaphore to wait until the preempt channel is
163      * it'll only release this mutex if postcopy is interrupted, so that
164      * the ram load main thread will take this mutex over and properly
173     /* This is shared for all postcopy channels */
205      * This semaphore is used to allow the ram fast load thread (only when
208      * thread will kick the fast ram load thread using this semaphore.
225      * the per-ramblock receivedmap.  Note! This does not guarantee consistency
228      * for that page already.  This is intended so that the mutex won't
230      * this should be enough to make sure the page_requested tree always
238      * will use this condvar to synchronize, so the main thread will always
244      * Number of devices that have yet to approve switchover. When this reaches
246      * is needed as this field is updated serially.
284      * It is posted when the preempt channel is established.  Note: this is
286      * post to this sem every time a new preempt channel is created in the
293      * won't yield or hang during the critical section, since this lock will be
315      * this threshold; it's calculated from the requested downtime and
332          * way to do this, so this bool makes it slightly more elegant.
333          * Checking from_dst_file for this is racy because from_dst_file will
339          * path thread.  The migration thread can wait() on this sem, while
345          * We post to this when we got one PONG from dest. So far it's an
414      * This variable only affects behavior when postcopy preempt mode is
437      * should probably just keep this value untouched after set by the
445      * This assures that we can't mix pages from one iteration through
447      * only need to do this flush after we have go through all the
449      * section.  This is suboptimal (we flush too many times).
455      * This variable only makes sense when set on the machine that is
480      * NOTE: Regardless of the state of this option, a premature
487      * This decides the size of guest memory chunk that will be used
497      * This save hostname when out-going migration starts
509     /* Is this a rdma migration */