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path: root/migration/postcopy-ram.c
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2016-06-16os-posix: include sys/mman.hPaolo Bonzini
qemu/osdep.h checks whether MAP_ANONYMOUS is defined, but this check is bogus without a previous inclusion of sys/mman.h. Include it in sysemu/os-posix.h and remove it from everywhere else. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-07all: Remove unnecessary glib.h includesPeter Maydell
Remove glib.h includes, as it is provided by osdep.h. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-05-29exec: remove ram_addr argument from qemu_ram_block_from_hostPaolo Bonzini
Of the two callers, one does not use it, and the other can compute it itself based on the other output argument (offset) and the RAMBlock. Reviewed-by: Marc-André Lureau <marcandre.lureau@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-26migration/postcopy-ram: Guard use of sys/eventfd.h with CONFIG_EVENTFDMatthew Fortune
sys/eventfd.h was being guarded only by a check for linux but does not exist on older distributions like CentOS 5. Move the include into the code that uses it and add an appropriate guard. Signed-off-by: Matthew Fortune <matthew.fortune@imgtec.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <6D39441BF12EF246A7ABCE6654B023536BB85DEB@hhmail02.hh.imgtec.org> Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-02-05migration: rename 'file' in MigrationState to 'to_dst_file'zhanghailiang
Rename the 'file' member of MigrationState to 'to_dst_file' to be consistent with to_src_file, from_src_file and from_dst_file. Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Message-Id: <1452829066-9764-3-git-send-email-zhang.zhanghailiang@huawei.com> Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-01-29migration: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1453832250-766-2-git-send-email-peter.maydell@linaro.org
2015-11-25Assume madvise for (no)hugepage worksDr. David Alan Gilbert
madvise() returns EINVAL in the case of many failures, but also returns it in cases where the host kernel doesn't have THP enabled. Postcopy only really cares that THP is off before it detects faults, and turns it back on afterwards; so we're going to have to assume that if the madvise fails then the host just doesn't do THP and we can carry on with the postcopy. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Tested-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10Inhibit ballooning during postcopyDr. David Alan Gilbert
Postcopy detects accesses to pages that haven't been transferred yet using userfaultfd, and it causes exceptions on pages that are 'not present'. Ballooning also causes pages to be marked as 'not present' when the guest inflates the balloon. Potentially a balloon could be inflated to discard pages that are currently inflight during postcopy and that may be arriving at about the same time. To avoid this confusion, disable ballooning during postcopy. When disabled we drop balloon requests from the guest. Since ballooning is generally initiated by the host, the management system should avoid initiating any balloon instructions to the guest during migration, although it's not possible to know how long it would take a guest to process a request made prior to the start of migration. Guest initiated ballooning will not know if it's really freed a page of host memory or not. Queueing the requests until after migration would be nice, but is non-trivial, since the set of inflate/deflate requests have to be compared with the state of the page to know what the final outcome is allowed to be. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10Disable mlock around incoming postcopyDr. David Alan Gilbert
Userfault doesn't work with mlock; mlock is designed to nail down pages so they don't move, userfault is designed to tell you when they're not there. munlock the pages we userfault protect before postcopy. mlock everything again at the end if mlock is enabled. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10Postcopy: Mark nohugepage before discardDr. David Alan Gilbert
Prior to servicing userfault requests we must ensure we've not got huge pages in the area that might include non-transferred memory, since a hugepage could incorrectly mark the whole huge page as present. We mark the area as non-huge page (nhp) just before we perform discards; the discard code now tells us to discard any areas that haven't been sent (as well as any that are redirtied); any already formed transparent-huge-pages get fragmented by this discard process if they cotnain any discards. Transparent huge pages that have been entirely transferred and don't contain any discards are not broken by this mechanism; they stay as huge pages. By starting postcopy after a full precopy pass, many of the pages then stay as huge pages; this is important for maintaining performance after the end of the migration. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10Postcopy; Handle userfault requestsDr. David Alan Gilbert
userfaultfd is a Linux syscall that gives an fd that receives a stream of notifications of accesses to pages registered with it and allows the program to acknowledge those stalls and tell the accessing thread to carry on. We convert the requests from the kernel into messages back to the source asking for the pages. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10postcopy_ram.c: place_page and helpersDr. David Alan Gilbert
postcopy_place_page (etc) provide a way for postcopy to place a page into guests memory atomically (using the copy ioctl on the ufd). Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10postcopy: ram_enable_notify to switch on userfaultDr. David Alan Gilbert
Mark the area of RAM as 'userfault' Start up a fault-thread to handle any userfaults we might receive from it (to be filled in later) Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10postcopy: Incoming initialisationDr. David Alan Gilbert
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10migration_completion: Take current stateDr. David Alan Gilbert
Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we complete migration, and we need to know which we expect to be in to change state safely. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10postcopy: OS support testDr. David Alan Gilbert
Provide a check to see if the OS we're running on has all the bits needed for postcopy. Creates postcopy-ram.c which will get most of the other helpers we need. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>