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path: root/migration/postcopy-ram.c
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2017-05-31migration: Create savevm.h for functions exported from savevm.cJuan Quintela
This removes last trace of migration functions from sysemu/sysemu.h. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2017-05-18exec: Create include for target_page_size()Juan Quintela
That is the only function that we need from exec.c, and having to include the whole sysemu.h for this. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- /me leans to be less sloppy with copyright notices thanks Dave
2017-05-18migration: Remove qemu-file.h from vmstate.hJuan Quintela
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> -- minor rearangements due to the rebase
2017-05-18postcopy: Require RAMBlocks that are whole pagesDr. David Alan Gilbert
It turns out that it's legal to create a VM with RAMBlocks that aren't a multiple of the pagesize in use; e.g. a 1025M main memory using 2M host pages. That breaks postcopy's atomic placement of pages, so disallow it. 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>
2017-05-17migration: Move postcopy stuff to postcopy-ram.cJuan Quintela
Yes, we don't have a good place to put that stuff. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-05-04migration: Move postcopy-ram.h to migration/Juan Quintela
It is internal to migration, not intended for other users. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-05-04ram: Split dirty bitmap by RAMBlockJuan Quintela
Both the ram bitmap and the unsent bitmap are split by RAMBlock. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com> Reviewed-by: Peter Xu <peterx@redhat.com> -- Fix compilation when DEBUG_POSTCOPY is enabled (thanks Hailiang)
2017-04-21ram: ram_discard_range() don't use the mis parameterJuan Quintela
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
2017-04-21ram: Rename qemu_target_page_bits() to qemu_target_page_size()Juan Quintela
It was used as a size in all cases except one. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-03-16postcopy: Check for shared memoryDr. David Alan Gilbert
Postcopy doesn't support migration of RAM shared with another process yet (we've got a bunch of things to understand). Check for the case and don't allow postcopy to be enabled. 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>
2017-02-28postcopy: Add extra check for COPY functionDr. David Alan Gilbert
As an extra sanity check, make sure the region we're registering can perform UFFDIO_COPY; the COPY will fail later but this gives a cleaner failure. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-17-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-28postcopy: Check for userfault+hugepage featureDr. David Alan Gilbert
We need extra Linux kernel support (~4.11) to support userfaults on hugetlbfs; check for them. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-15-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-28postcopy: Allow hugepagesDr. David Alan Gilbert
Allow huge pages in postcopy. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-13-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-28postcopy: Mask fault addresses to huge page boundaryDr. David Alan Gilbert
Currently the fault address received by userfault is rounded to the host page boundary and a host page is requested from the source. Use the current RAMBlock page size instead of the general host page size so that for RAMBlocks backed by huge pages we request the whole huge page. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-11-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-28postcopy: Use temporary for placing zero huge pagesDr. David Alan Gilbert
The kernel can't do UFFDIO_ZEROPAGE for huge pages, so we have to allocate a temporary (always zero) page and use UFFDIO_COPYPAGE on it. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-9-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-28postcopy: Plumb pagesize down into place helpersDr. David Alan Gilbert
Now we deal with normal size pages and huge pages we need to tell the place handlers the size we're dealing with and make sure the temporary page is large enough. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-8-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-02-28exec: ram_block_discard_rangeDr. David Alan Gilbert
Create ram_block_discard_range in exec.c to replace postcopy_ram_discard_range and most of ram_discard_range. Those two routines are a bit of a weird combination, and ram_discard_range is about to get more complex for hugepages. It's OS dependent code (so shouldn't be in migration/ram.c) but it needs quite a bit of the innards of RAMBlock so doesn't belong in the os*.c. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20170224182844.32452-5-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2016-10-13migration/postcopy: Explicitly disallow huge pagesDr. David Alan Gilbert
At the moment postcopy will fail as soon as qemu tries to register userfault on the RAMBlock pages that are backed by hugepages. However, the kernel is going to get userfault support for hugepage at some point, and we've not got the rest of the QEMU code to support it yet, so fail neatly with an error like: Postcopy doesn't support hugetlbfs yet (/objects/mem1) 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>
2016-08-11migration: mmap error check fixEvgeny Yakovlev
mmap man page: "On success, mmap() returns a pointer to the mapped area. On error, the value MAP_FAILED (that is, (void *) -1) is returned, and errno is set to indicate the cause of the error." The check in postcopy_get_tmp_page is definitely wrong and should be fixed. Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> CC: Juan Quintela <quintela@redhat.com> CC: Amit Shah <amit.shah@redhat.com> Message-Id: <1469785705-16670-1-git-send-email-den@openvz.org> Signed-off-by: Amit Shah <amit.shah@redhat.com>
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>