Commit Graph

42245 Commits

Author SHA1 Message Date
Alberto Garcia a39a24fbb0 block: check for existing device IDs in external_snapshot_prepare()
The 'snapshot-node-name' parameter of blockdev-snapshot-sync allows
setting the node name of the image that is going to be created.

Before creating the image, external_snapshot_prepare() checks that the
name is not already being used. The check is however incomplete since
it only considers existing node names, but node names must not clash
with device IDs either because they share the same namespace.

If the user attempts to create a snapshot using the name of an
existing device for the 'snapshot-node-name' parameter the operation
will eventually fail, but only after the new image has been created.

This patch replaces bdrv_find_node() with bdrv_lookup_bs() to extend
the check to existing device IDs, and thus detect possible name
clashes before the new image is created.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:25:47 +01:00
Max Reitz adfe20303f iotests: Add test for change-related QMP commands
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:25:47 +01:00
Max Reitz baead0abef hmp: Add read-only-mode option to change command
Expose the new read-only-mode option of 'blockdev-change-medium' for the
'change' HMP command.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:25:47 +01:00
Max Reitz 39ff43d9e1 blockdev: read-only-mode for blockdev-change-medium
Add an option to qmp_blockdev_change_medium() which allows changing the
read-only status of the block device whose medium is changed.

Some drives do not have a inherently fixed read-only status; for
instance, floppy disks can be set read-only or writable independently of
the drive. Some users may find it useful to be able to therefore change
the read-only status of a block device when changing the medium.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:23:34 +01:00
Max Reitz 1068674927 hmp: Use blockdev-change-medium for change command
Use separate code paths for the two overloaded functions of the 'change'
HMP command, and invoke the 'blockdev-change-medium' QMP command if used
on a block device (by calling qmp_blockdev_change_medium()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz 24fb413300 qmp: Introduce blockdev-change-medium
Introduce a new QMP command 'blockdev-change-medium' which is intended
to replace the 'change' command for block devices. The existing function
qmp_change_blockdev() is accordingly renamed to
qmp_blockdev_change_medium().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz f1f5706657 block: Inquire tray state before tray-moved events
blk_dev_change_media_cb() is called for all potential tray movements;
however, it is possible to request closing the tray but nothing actually
happening (on a floppy disk drive without a medium).

Thus, the actual tray status should be inquired before sending a
tray-moved event (and an event should be sent whenever the status
changed).

Checking @load is now superfluous; it was necessary because it was
possible to change a medium without having explicitly opened the tray
and closed it again (or it might have been possible, at least). This is
no longer possible, though.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz de2c6c0536 blockdev: Implement change with basic operations
Implement 'change' on block devices by calling blockdev-open-tray,
blockdev-remove-medium, blockdev-insert-medium (a variation of that
which does not need a node-name) and blockdev-close-tray.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz 38f54bd1ee blockdev: Implement eject with basic operations
Implement 'eject' by calling blockdev-open-tray and
blockdev-remove-medium.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz d129988289 blockdev: Add blockdev-insert-medium
And a helper function for that, which directly takes a pointer to the
BDS to be inserted instead of its node-name (which will be used for
implementing 'change' using blockdev-insert-medium).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz 2814f67271 blockdev: Add blockdev-remove-medium
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz abaaf59d24 blockdev: Add blockdev-close-tray
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz 7d8a9f71b9 blockdev: Add blockdev-open-tray
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:47 +01:00
Max Reitz 38cb18f5b7 block: Add functions for inheriting a BBRS
In order to open a BDS which inherits a BB's root state,
blk_get_open_flags_from_root_state() is used to inquire the flags to be
passed to bdrv_open(), and blk_apply_root_state() is used to apply the
remaining state after the BDS has been opened.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:46 +01:00
Max Reitz c69a4dd899 block: Make bdrv_states public
When inserting a BDS tree into a BB, we will need to add the root BDS to
this list. Since we will want to do that in the blockdev-insert-medium
implementation in blockdev.c, we will need access to it there.

This patch is not exactly elegant, but bdrv_states will be removed in
the future anyway because we no longer need it since we have BBs.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:46 +01:00
Max Reitz 1c95f7e1af block: Add blk_remove_bs()
This function removes the BlockDriverState associated with the given
BlockBackend from that BB and sets the BDS pointer in the BB to NULL.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:46 +01:00
Alberto Garcia 9f4ed6fbd2 block: Don't call blk_bs() twice in bdrv_lookup_bs()
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:22:46 +01:00
Peter Maydell 3c07587d49 ppc patch queue - 2015-11-11
Highlights:
   - Updated SLOF version for "pseries machine
   - Bugfix / cleanup for KVM hash page table allocation
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Merge remote-tracking branch 'remotes/dgibson/tags/ppc-next-20151111' into staging

ppc patch queue - 2015-11-11

Highlights:
  - Updated SLOF version for "pseries machine
  - Bugfix / cleanup for KVM hash page table allocation

# gpg: Signature made Wed 11 Nov 2015 02:30:51 GMT using RSA key ID 20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-next-20151111:
  spapr: Handle failure of KVM_PPC_ALLOCATE_HTAB ioctl
  ppc: Let kvmppc_reset_htab() return 0 for !CONFIG_KVM
  pseries: Update SLOF firmware image to qemu-slof-20151103
  ppc: Add/Re-introduce MMU model definitions needed by PR KVM

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-11-11 09:34:18 +00:00
Bharata B Rao b41d320fef spapr: Handle failure of KVM_PPC_ALLOCATE_HTAB ioctl
KVM_PPC_ALLOCATE_HTAB ioctl can return -ENOMEM for KVM guests and QEMU
never handled this correctly. But this didn't cause any problems till
now as KVM_PPC_ALLOCATE_HTAB ioctl returned with smaller than requested
HTAB when enough contiguous memory wasn't available in the host.
After the proposed kernel change: https://patchwork.ozlabs.org/patch/530501/,
KVM_PPC_ALLOCATE_HTAB ioctl will not fallback to lower sized HTAB
allocation and will fail if requested HTAB size can't be met.

Check for such failures in QEMU and abort appropriately. This will
prevent guest kernel from hanging/freezing during early boot by doing
graceful exit when host is unable to allocate requested HTAB.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2015-11-11 13:29:04 +11:00
Bharata B Rao a3166f8f6e ppc: Let kvmppc_reset_htab() return 0 for !CONFIG_KVM
The !CONFIG_KVM implementation of kvmppc_reset_htab() returns -1
by default. Change this to return 0 so that we fall back to user space
HTAB allocation for emulated guests.

This fixes the make check failures for ppc64 emulated target.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2015-11-11 13:29:04 +11:00
Alexey Kardashevskiy 1210481958 pseries: Update SLOF firmware image to qemu-slof-20151103
The changes are:
1. supports recent binutils;
2. 64bit BARs behind PCI bridges supported;
3. Many fixes for USB keyboard support - keys, XHCI;
4. virtio-vga support.

This image was built with:
gcc version 4.8.3 20140911 (Red Hat 4.8.3-7) (GCC)
GNU ld version 2.23.2

The full changelog is:
  > version: update to 20151103
  > documentation: Add a clause about signing off
  > qemu/js2x/client: Support binutils >= 2.25.1
  > Fix special keys on USB
  > Fix function keys on USB
  > pci-scan: program 64-bit mem bar range in pci-bridge bar
  > Allow to build SLOF on Little Endian host
  > usb-xhci: add keyboard support
  > usb-xhci: ready the link trb early
  > usb-xhci: scan usb high speed ports
  > usb-xhci: bulk improve event handling loop
  > usb-xhci: return on allocation failure
  > usb-xhci: add delay in shutdown path
  > usb-xhci: event trbs does not need link trb
  > usb-hid: refactor usb key reading
  > takeover: Fix header includes
  > board-js2x: Add missing file dma-function.fs
  > vga: Add support for virtio-vga
  > qemu-vga: Use MMIO BAR instead of legacy IO ports
  > slof: Change call_c() function to a proper assembler function

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2015-11-11 13:28:45 +11:00
Bharata B Rao ba3ecda05e ppc: Add/Re-introduce MMU model definitions needed by PR KVM
Commit aa4bb58752 (ppc: Add mmu_model defines for arch 2.03 and 2.07)
removed the mmu_model definition POWERPC_MMU_2_06a which is needed by
PR KVM. Reintroduce it and also add POWERPC_MMU_2_07a.

This fixes QEMU crash (qemu: fatal: Unknown MMU model) during booting
of PR KVM guest.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2015-11-11 11:05:30 +11:00
Peter Maydell d93ae5b696 VFIO updates 2015-11-10
- Make Windows happy with vfio-pci devices exposed on conventional
    PCI buses on q35 by hiding PCIe capability (Alex Williamson)
  - Convert to g_new() where appropriate (Markus Armbruster)
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Merge remote-tracking branch 'remotes/awilliam/tags/vfio-update-20151110.0' into staging

VFIO updates 2015-11-10

 - Make Windows happy with vfio-pci devices exposed on conventional
   PCI buses on q35 by hiding PCIe capability (Alex Williamson)
 - Convert to g_new() where appropriate (Markus Armbruster)

# gpg: Signature made Tue 10 Nov 2015 19:46:41 GMT using RSA key ID 3BB08B22
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>"
# gpg:                 aka "Alex Williamson <alex@shazbot.org>"
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>"
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>"

* remotes/awilliam/tags/vfio-update-20151110.0:
  vfio: Use g_new() & friends where that makes obvious sense
  vfio/pci: Hide device PCIe capability on non-express buses for PCIe VMs

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-11-10 22:21:42 +00:00
Markus Armbruster bdd81addf4 vfio: Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).  Same Coccinelle semantic patch as in commit b45c03f.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-10 12:11:08 -07:00
Alex Williamson 0282abf078 vfio/pci: Hide device PCIe capability on non-express buses for PCIe VMs
When we have a PCIe VM, such as Q35, guests start to care more about
valid configurations of devices relative to the VM view of the PCI
topology.  Windows will error with a Code 10 for an assigned device if
a PCIe capability is found for a device on a conventional bus.  We
also have the possibility of IOMMUs, like VT-d, where the where the
guest may be acutely aware of valid express capabilities on physical
hardware.

Some devices, like tg3 are adversely affected by this due to driver
dependencies on the PCIe capability.  The only solution for such
devices is to attach them to an express capable bus in the VM.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-10 12:11:08 -07:00
Peter Maydell a77067f6ac migration/next for 20151110
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Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20151110' into staging

migration/next for 20151110

# gpg: Signature made Tue 10 Nov 2015 14:23:26 GMT using RSA key ID 5872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"

* remotes/juanquintela/tags/migration/20151110: (57 commits)
  migration: qemu_savevm_state_cleanup becomes mandatory operation
  Inhibit ballooning during postcopy
  Disable mlock around incoming postcopy
  End of migration for postcopy
  Postcopy: Mark nohugepage before discard
  postcopy: Wire up loadvm_postcopy_handle_ commands
  Start up a postcopy/listener thread ready for incoming page data
  Postcopy; Handle userfault requests
  Round up RAMBlock sizes to host page sizes
  Host page!=target page: Cleanup bitmaps
  Don't iterate on precopy-only devices during postcopy
  Don't sync dirty bitmaps in postcopy
  postcopy: Check order of received target pages
  Postcopy: Use helpers to map pages during migration
  postcopy_ram.c: place_page and helpers
  Page request: Consume pages off the post-copy queue
  Page request: Process incoming page request
  Page request: Add MIG_RP_MSG_REQ_PAGES reverse command
  Postcopy: End of iteration
  Postcopy: Postcopy startup in migration thread
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-11-10 17:49:39 +00:00
Denis V. Lunev 15b3b8eaae migration: qemu_savevm_state_cleanup becomes mandatory operation
since commit
    commit 94f5a43704
    Author: Liang Li <liang.z.li@intel.com>
    Date:   Mon Nov 2 15:37:00 2015 +0800

    migration: defer migration_end & blk_mig_cleanup

when actual .cleanup callbacks calling was removed from complete operations.

The patch fixes regression introduced by the commit above results in
100% reliable assert for virtio-scsi VM with iothreads enabled during
'virsh create-snapshot' operation:
    assert(i != mr->ioeventfd_nb);
    memory_region_del_eventfd
    virtio_pci_set_host_notifier_internal
    virtio_pci_set_host_notifier
    virtio_scsi_dataplane_start
    virtio_scsi_handle_cmd
    virtio_queue_notify_vq
    virtio_queue_host_notifier_read
    aio_dispatch

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 371ff5a3f0 Inhibit ballooning during postcopy
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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 58b7c17e22 Disable mlock around incoming postcopy
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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert e9bef235d9 End of migration for postcopy
Tweak the end of migration cleanup; we don't want to close stuff down
at the end of the main stream, since the postcopy is still sending pages
on the other thread.

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert f952710757 Postcopy: Mark nohugepage before discard
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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 27c6825bd3 postcopy: Wire up loadvm_postcopy_handle_ commands
Wire up more of the handlers for the commands on the destination side,
in particular loadvm_postcopy_handle_run now has enough to start the
guest running.

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert c76201ab52 Start up a postcopy/listener thread ready for incoming page data
The loading of a device state (during postcopy) may access guest
memory that's still on the source machine and thus might need
a page fill; split off a separate thread that handles the incoming
page data so that the original incoming migration code can finish
off the device data.

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert c4faeed231 Postcopy; Handle userfault requests
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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 4ed023ce2a Round up RAMBlock sizes to host page sizes
RAMBlocks that are not a multiple of host pages in length
cause problems for postcopy (I've seen an ACPI table on aarch64
be 5k in length - i.e. 5x target-page), so round RAMBlock sizes
up to a host-page.

This potentially breaks migration compatibility due to changes
in RAMBlock sizes; however:
   1) x86 and s390 I think always have host=target page size
   2) When I've tried on Power the block sizes already seem aligned.
   3) I don't think there's anything else that maintains per-version
      machine-types for compatibility.

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 99e314ebca Host page!=target page: Cleanup bitmaps
Prior to the start of postcopy, ensure that everything that will
be transferred later is a whole host-page in size.

This is accomplished by discarding partially transferred host pages
and marking any that are partially dirty as fully dirty.

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 35ecd943e7 Don't iterate on precopy-only devices during postcopy
During the postcopy phase we must not call the iterate method on
precopy-only devices, since they may have done some cleanup during
the _complete call at the end of the precopy phase.

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert 663e6c1df8 Don't sync dirty bitmaps in postcopy
Once we're in postcopy the source processors are stopped and memory
shouldn't change any more, so there's no need to look at the dirty
map.

There are two notes to this:
  1) If we do resync and a page had changed then the page would get
     sent again, which the destination wouldn't allow (since it might
     have also modified the page)
  2) Before disabling this I'd seen very rare cases where a page had been
     marked dirtied although the memory contents are apparently identical

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>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert c53b7ddc61 postcopy: Check order of received target pages
Ensure that target pages received within a host page are in order.
This shouldn't trigger, but in the cases where the sender goes
wrong and sends stuff out of order it produces a corruption that's
really nasty to debug.

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert a71808772a Postcopy: Use helpers to map pages during migration
In postcopy, the destination guest is running at the same time
as it's receiving pages; as we receive new pages we must put
them into the guests address space atomically to avoid a running
CPU accessing a partially written page.

Use the helpers in postcopy-ram.c to map these pages.

qemu_get_buffer_in_place is used to avoid a copy out of qemu_file
in the case that postcopy is going to do a copy anyway.

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert 696ed9a9b3 postcopy_ram.c: place_page and helpers
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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert a82d593b61 Page request: Consume pages off the post-copy queue
When transmitting RAM pages, consume pages that have been queued by
MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.

Note:
  a) After a queued page the linear walk carries on from after the
unqueued page; there is a reasonable chance that the destination
was about to ask for other closeby pages anyway.

  b) We have to be careful of any assumptions that the page walking
code makes, in particular it does some short cuts on its first linear
walk that break as soon as we do a queued page.

  c) We have to be careful to not break up host-page size chunks, since
this makes it harder to place the pages on the destination.

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert 6c595cdee1 Page request: Process incoming page request
On receiving MIG_RPCOMM_REQ_PAGES look up the address and
queue the page.

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert 1e2d90ebc5 Page request: Add MIG_RP_MSG_REQ_PAGES reverse command
Add MIG_RP_MSG_REQ_PAGES command on Return path for the postcopy
destination to request a page from the source.

Two versions exist:
   MIG_RP_MSG_REQ_PAGES_ID that includes a RAMBlock name and start/len
   MIG_RP_MSG_REQ_PAGES that just has start/len for use with the same
                        RAMBlock as a previous MIG_RP_MSG_REQ_PAGES_ID

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert b10ac0c42c Postcopy: End of iteration
The end of migration in postcopy is a bit different since some of
the things normally done at the end of migration have already been
done on the transition to postcopy.

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert 1d34e4bf6a Postcopy: Postcopy startup in migration thread
Rework the migration thread to setup and start postcopy.

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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert f0a227ade4 postcopy: ram_enable_notify to switch on userfault
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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert 1caddf8a81 postcopy: Incoming initialisation
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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert e0b266f01d migration_completion: Take current state
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>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert f3f491fcd6 Postcopy: Maintain unsentmap
Maintain an 'unsentmap' of pages that have yet to be sent.
This is used in the following patches to discard some set of
the pages already sent as we enter postcopy mode.

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>
2015-11-10 15:00:27 +01:00