The virtio-balloon always works in units of 4kiB (BALLOON_PAGE_SIZE), but
we can only actually discard memory in units of the host page size.
Now, we handle this very badly: we silently ignore balloon requests that
aren't host page aligned, and for requests that are host page aligned we
discard the entire host page. The latter can corrupt guest memory if its
page size is smaller than the host's.
The obvious choice would be to disable the balloon if the host page size is
not 4kiB. However, that would break the special case where host and guest
have the same page size, but that's larger than 4kiB. That case currently
works by accident[1] - and is used in practice on many production POWER
systems where 64kiB has long been the Linux default page size on both host
and guest.
To make the balloon safe, without breaking that useful special case, we
need to accumulate 4kiB balloon requests until we have a whole contiguous
host page to discard.
We could in principle do that across all guest memory, but it would require
a large bitmap to track. This patch represents a compromise: we track
ballooned subpages for a single contiguous host page at a time. This means
that if the guest discards all 4kiB chunks of a host page in succession,
we will discard it. This is the expected behaviour in the (host page) ==
(guest page) != 4kiB case we want to support.
If the guest scatters 4kiB requests across different host pages, we don't
discard anything, and issue a warning. Not ideal, but at least we don't
corrupt guest memory as the previous version could.
Warning reporting is kind of a compromise here. Determining whether we're
in a problematic state at realize() time is tricky, because we'd have to
look at the host pagesizes of all memory backends, but we can't really know
if some of those backends could be for special purpose memory that's not
subject to ballooning.
Reporting only when the guest tries to balloon a partial page also isn't
great because if the guest page size happens to line up it won't indicate
that we're in a non ideal situation. It could also cause alarming repeated
warnings whenever a migration is attempted.
So, what we do is warn the first time the guest attempts balloon a partial
host page, whether or not it will end up ballooning the rest of the page
immediately afterwards.
[1] Because when the guest attempts to balloon a page, it will submit
requests for each 4kiB subpage. Most will be ignored, but the one
which happens to be host page aligned will discard the whole lot.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190214043916.22128-6-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Currently, virtio-balloon uses madvise() with MADV_DONTNEED to actually
discard RAM pages inserted into the balloon. This is basically a Linux
only interface (MADV_DONTNEED exists on some other platforms, but doesn't
always have the same semantics). It also doesn't work on hugepages and has
some other limitations.
It turns out that postcopy also needs to discard chunks of memory, and uses
a better interface for it: ram_block_discard_range(). It doesn't cover
every case, but it covers more than going direct to madvise() and this
gives us a single place to update for more possibilities in future.
There are some subtleties here to maintain the current balloon behaviour:
* For now, we just ignore requests to balloon in a hugepage backed region.
That matches current behaviour, because MADV_DONTNEED on a hugepage would
simply fail, and we ignore the error.
* If host page size is > BALLOON_PAGE_SIZE we can frequently call this on
non-host-page-aligned addresses. These would also fail in madvise(),
which we then ignored. ram_block_discard_range() error_report()s calls
on unaligned addresses, so we explicitly check that case to avoid
spamming the logs.
* We now call ram_block_discard_range() with the *host* page size, whereas
we previously called madvise() with BALLOON_PAGE_SIZE. Surprisingly,
this also matches existing behaviour. Although the kernel fails madvise
on unaligned addresses, it will round unaligned sizes *up* to the host
page size. Yes, this means that if BALLOON_PAGE_SIZE < guest page size
we can incorrectly discard more memory than the guest asked us to. I'm
planning to address that soon.
Errors other than the ones discussed above, will now be reported by
ram_block_discard_range(), rather than silently ignored, which means we
have a much better chance of seeing when something is going wrong.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20190214043916.22128-5-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This replaces the balloon_page() internal interface with
ballon_inflate_page(), with a slightly different interface. The new
interface will make future alterations simpler.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20190214043916.22128-4-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The virtio-balloon device's verification of the address given to it by the
guest has a number of faults:
* The addresses here are guest physical addresses, which should be
'hwaddr' rather than 'ram_addr_t' (the distinction is admittedly
pretty subtle and confusing)
* We don't check for section.mr being NULL, which is the main way that
memory_region_find() reports basic failures. We really need to check
that before looking at any other section fields, because
memory_region_find() doesn't initialize them on the failure path
* We're passing a length of '1' to memory_region_find(), but really the
guest is requesting that we put the entire page into the balloon,
so it makes more sense to call it with BALLOON_PAGE_SIZE
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20190214043916.22128-3-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When the balloon is inflated, we discard memory place in it using madvise()
with MADV_DONTNEED. And when we deflate it we use MADV_WILLNEED, which
sounds like it makes sense but is actually unnecessary.
The misleadingly named MADV_DONTNEED just discards the memory in question,
it doesn't set any persistent state on it in-kernel; all that's necessary
to bring the memory back is to touch it. MADV_WILLNEED in contrast
specifically says that the memory will be used soon and faults it in.
This patch simplify's the balloon operation by dropping the madvise()
on deflate. This might have an impact on performance - it will move a
delay at deflate time until that memory is actually touched, which
might be more latency sensitive. However:
* Memory that's being given back to the guest by deflating the
balloon *might* be used soon, but it equally could just sit around
in the guest's pools until needed (or even be faulted out again if
the host is under memory pressure).
* Usually, the timescale over which you'll be adjusting the balloon
is long enough that a few extra faults after deflation aren't
going to make a difference.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20190214043916.22128-2-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
In virtio_balloon_get_config() we initialize a struct virtio_balloon_config
which we then copy to guest memory. However, the local variable is not
zero initialized. This works OK at the moment because we initialize
all the fields in it; however an upcoming kernel header change will
add some new fields. If we don't zero out the whole struct then we
will start leaking a small amount of the contents of QEMU's stack
to the guest as soon as we update linux-headers/ to a set of headers
that includes the new fields.
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190118183603.24757-1-peter.maydell@linaro.org
The generated qapi_event_send_FOO() take an Error ** argument. They
can't actually fail, because all they do with the argument is passing it
to functions that can't fail: the QObject output visitor, and the
@qmp_emit callback, which is either monitor_qapi_event_queue() or
event_test_emit().
Drop the argument, and pass &error_abort to the QObject output visitor
and @qmp_emit instead.
Suggested-by: Eric Blake <eblake@redhat.com>
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180815133747.25032-4-peterx@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message rewritten, update to qapi-code-gen.txt corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Remove KVM specific tests in balloon_page(), instead marking
ballooning as inhibited without KVM_CAP_SYNC_MMU support.
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
qemu should read and report hugetlb page allocation
counts exported in the following kernel patch:
commit 4c3ca37c4a4394978fd0f005625f6064ed2b9a64
Author: Jonathan Helman <jonathan.helman@oracle.com>
Date: Mon Mar 19 11:00:35 2018 -0700
virtio_balloon: export hugetlb page allocation counts
Export the number of successful and failed hugetlb page
allocations via the virtio balloon driver. These 2 counts
come directly from the vm_events HTLB_BUDDY_PGALLOC and
HTLB_BUDDY_PGALLOC_FAIL.
Signed-off-by: Jonathan Helman <jonathan.helman@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
The previous commit improved compile time by including less of the
generated QAPI headers. This is impossible for stuff defined directly
in qapi-schema.json, because that ends up in headers that that pull in
everything.
Move everything but include directives from qapi-schema.json to new
sub-module qapi/misc.json, then include just the "misc" shard where
possible.
It's possible everywhere, except:
* monitor.c needs qmp-command.h to get qmp_init_marshal()
* monitor.c, ui/vnc.c and the generated qapi-event-FOO.c need
qapi-event.h to get enum QAPIEvent
Perhaps we'll get rid of those some other day.
Adding a type to qapi/migration.json now recompiles some 120 instead
of 2300 out of 5100 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-25-armbru@redhat.com>
[eblake: rebase to master]
Signed-off-by: Eric Blake <eblake@redhat.com>
- new stats in virtio balloon
- virtio eventfd rework for boot speedup
- vhost memory rework for boot speedup
- fixes and cleanups all over the place
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
virtio,vhost,pci,pc: features, fixes and cleanups
- new stats in virtio balloon
- virtio eventfd rework for boot speedup
- vhost memory rework for boot speedup
- fixes and cleanups all over the place
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Tue 13 Feb 2018 16:29:55 GMT
# gpg: using RSA key 281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg: aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17 0970 C350 3912 AFBE 8E67
# Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA 8A0D 281F 0DB8 D28D 5469
* remotes/mst/tags/for_upstream: (22 commits)
virtio-balloon: include statistics of disk/file caches
acpi-test: update FADT
lpc: drop pcie host dependency
tests: acpi: fix FADT not being compared to reference table
hw/pci-bridge: fix pcie root port's IO hints capability
libvhost-user: Support across-memory-boundary access
libvhost-user: Fix resource leak
virtio-balloon: unref the memory region before continuing
pci: removed the is_express field since a uniform interface was inserted
virtio-blk: enable multiple vectors when using multiple I/O queues
pci/bus: let it has higher migration priority
pci-bridge/i82801b11: clear bridge registers on platform reset
vhost: Move log_dirty check
vhost: Merge and delete unused callbacks
vhost: Clean out old vhost_set_memory and friends
vhost: Regenerate region list from changed sections list
vhost: Merge sections added to temporary list
vhost: Simplify ring verification checks
vhost: Build temporary section list and deref after commit
virtio: improve virtio devices initialization time
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Tomáš Golembiovský <tgolembi@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.
While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
Convert all the single line uses of fprintf(stderr, "warning:"..."\n"...
to use warn_report() instead. This helps standardise on a single
method of printing warnings to the user.
All of the warnings were changed using this command:
find ./* -type f -exec sed -i \
's|fprintf(.*".*warning[,:] \(.*\)\\n"\(.*\));|warn_report("\1"\2);|Ig' \
{} +
Some of the lines were manually edited to reduce the line length to below
80 charecters.
The #include lines were manually updated to allow the code to compile.
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com> [mips]
Message-Id: <ae8f8a7f0a88ded61743dff2adade21f8122a9e7.1505158760.git.alistair.francis@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A broken guest can specify physical addresses that correspond
to any memory region, but it shouldn't be able to change ROM.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: qemu-stable@nongnu.org
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The function undoes the effect of virtqueue_pop and doesn't do anything
destructive or irreversible so virtqueue_unpop is a more fitting name.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Replace the load/save with a vmsd.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Now all the usages of the old version of VMSTATE_VIRTIO_DEVICE are gone,
so we can get rid of the conditionals, and the old macro.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Use the new VMSTATE_VIRTIO_DEVICE macro.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Since there in wrapper around madvise(), the virtio-balloon
code is able to work without the precompiled directive, the
directive can be removed.
Signed-off-by: Liang Li <liang.z.li@intel.com>
Suggested-by: Thomas Huth <thuth@redhat.com>
Reviewd-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The statistics virtqueue is not migrated properly because virtio-balloon
does not include s->stats_vq_elem in the migration stream.
After migration the statistics virtqueue hangs because the host never
completes the last element (s->stats_vq_elem is NULL on the destination
QEMU). Therefore the guest never submits new elements and the virtqueue
is hung.
Instead of changing the migration stream format in an incompatible way,
detect the migration case and rewind the virtqueue so the last element
can be completed.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Suggested-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The one pending element is being freed but not discarded on device
reset, which causes svq->inuse to creep up, eventually hitting the
"Virtqueue size exceeded" error.
Properly discarding the element on device reset makes sure that its
buffers are unmapped and the inuse counter stays balanced.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Forcibly convert it to a vmstate wrapper; proper conversion
comes later.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*. The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL. The dealloc visitor is then greatly simplified.
All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**. This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.
For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-4-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
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>
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.
Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error. So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().
Generated code in qapi-visit.c has diffs resembling:
|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
| goto out_obj;
| }
| visit_type_ACPIOSTInfo_members(v, obj, &err);
|- error_propagate(errp, err);
|- err = NULL;
|+ if (err) {
|+ goto out_obj;
|+ }
|+ visit_check_struct(v, &err);
| out_obj:
|- visit_end_struct(v, &err);
|+ visit_end_struct(v);
| out:
and in qapi-event.c:
@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
| goto out;
| }
| visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, ¶m, &err);
|- visit_end_struct(v, err ? NULL : &err);
|+ if (!err) {
|+ visit_check_struct(v, &err);
|+ }
|+ visit_end_struct(v);
| if (err) {
| goto out;
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The balloon code currently calls madvise() with TARGET_PAGE_SIZE as
length parameter. Since the virtio-balloon protocol is always based
on 4k pages, no matter what the host and guest are using as page size,
this could cause problems: If TARGET_PAGE_SIZE is bigger than 4k, the
madvise call also destroys the 4k areas after the current one - which
might be wrong since the guest did not want free that area yet (in
case the guest used as smaller MMU page size than the hard-coded
TARGET_PAGE_SIZE). So to fix this issue, introduce a proper define
called BALLOON_PAGE_SIZE (which is 4096) to use this as the size
parameter for the madvise() call instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
If before loading snapshot we had set the timer of statistics, then after
applying snapshot the expiry time would be irrelevant for the restored
state of the virtual clocks. A simple fix is just to restart the timer
after loading snapshot.
For the user it may look like a long delay of statistics update after switch
to the snapshot.
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The patch for the kernel part is in linux-next already:
commit ac88e7c908b920866e529862f2b2f0129b254ab2
Author: Igor Redko <redkoi@virtuozzo.com>
Date: Thu Feb 18 09:23:01 2016 +1100
virtio_balloon: export 'available' memory to balloon statistics
Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory
statistics protocol, corresponding to 'Available' in /proc/meminfo.
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Igor Redko <redkoi@virtuozzo.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The segfault here is triggered by the driver notifying the stats queue
twice after adding a buffer to it. This effectively resets stats_vq_elem
back to NULL and QEMU crashes on the next stats timer tick in
balloon_stats_poll_cb.
This is a regression introduced in 51b19ebe43, although admittedly
the device assumed too much about the stats queue protocol even before
that commit. This commit adds a few more checks and ensures that the one
stats buffer gets deallocated on device reset.
Cc: qemu-stable@nongnu.org
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
For now there are only two dimm's: pc-dimm and nvdimm. This patch is
actually needed to disable ballooning on nvdimm. But, to avoid future
bugs, instead of disallowing nvdimm, we allow only pc-dimm. So, if
someone adds new dimm which should be balloon-able, then this ability
should be explicitly specified here.
Why ballooning for nvdimm should be disabled for now:
NVDIMM for now is planned to use as a backing store for DAX filesystem
in the guest and thus this memory is excluded from guest memory
management and LRUs.
In this case libvirt running QEMU along with configured balloon almost
immediately inflates balloon and effectively kill the guest as
qemu counts nvdimm as part of the ram.
Counting dimm devices as part of the ram for ballooning was started from
commit 463756d03:
virtio-balloon: Fix balloon not working correctly when hotplug memory
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Use pc_dimm_built_list() instead of qmp_pc_dimm_device_list()
Actually, Qapi is not related to this internal helper.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
get_current_ram_size() is used only in virtio-balloon.c
This patch moves it into virtio-balloon and make it static, to allow
some balloon-specific tuning.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
visit_start_struct() and visit_type_enum() had a 'kind' argument
that was usually set to either the stringized version of the
corresponding qapi type name, or to NULL (although some clients
didn't even get that right). But nothing ever used the argument.
It's even hard to argue that it would be useful in a debugger,
as a stack backtrace also tells which type is being visited.
Therefore, drop the 'kind' argument as dead.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-22-git-send-email-eblake@redhat.com>
[Harmless rebase mistake cleaned up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Similar to the previous patch, it's nice to have all functions
in the tree that involve a visitor and a name for conversion to
or from QAPI to consistently stick the 'name' parameter next
to the Visitor parameter.
Done by manually changing include/qom/object.h and qom/object.c,
then running this Coccinelle script and touching up the fallout
(Coccinelle insisted on adding some trailing whitespace).
@ rule1 @
identifier fn;
typedef Object, Visitor, Error;
identifier obj, v, opaque, name, errp;
@@
void fn
- (Object *obj, Visitor *v, void *opaque, const char *name,
+ (Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp) { ... }
@@
identifier rule1.fn;
expression obj, v, opaque, name, errp;
@@
fn(obj, v,
- opaque, name,
+ name, opaque,
errp)
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-20-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
JSON uses "name":value, but many of our visitor interfaces were
called with visit_type_FOO(v, &value, name, errp). This can be
a bit confusing to have to mentally swap the parameter order to
match JSON order. It's particularly bad for visit_start_struct(),
where the 'name' parameter is smack in the middle of the
otherwise-related group of 'obj, kind, size' parameters! It's
time to do a global swap of the parameter ordering, so that the
'name' parameter is always immediately after the Visitor argument.
Additional reason in favor of the swap: the existing include/qjson.h
prefers listing 'name' first in json_prop_*(), and I have plans to
unify that file with the qapi visitors; listing 'name' first in
qapi will minimize churn to the (admittedly few) qjson.h clients.
Later patches will then fix docs, object.h, visitor-impl.h, and
those clients to match.
Done by first patching scripts/qapi*.py by hand to make generated
files do what I want, then by running the following Coccinelle
script to affect the rest of the code base:
$ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'`
I then had to apply some touchups (Coccinelle insisted on TAB
indentation in visitor.h, and botched the signature of
visit_type_enum() by rewriting 'const char *const strings[]' to
the syntactically invalid 'const char*const[] strings'). The
movement of parameters is sufficient to provoke compiler errors
if any callers were missed.
// Part 1: Swap declaration order
@@
type TV, TErr, TObj, T1, T2;
identifier OBJ, ARG1, ARG2;
@@
void visit_start_struct
-(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp)
+(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
{ ... }
@@
type bool, TV, T1;
identifier ARG1;
@@
bool visit_optional
-(TV v, T1 ARG1, const char *name)
+(TV v, const char *name, T1 ARG1)
{ ... }
@@
type TV, TErr, TObj, T1;
identifier OBJ, ARG1;
@@
void visit_get_next_type
-(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp)
+(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp)
{ ... }
@@
type TV, TErr, TObj, T1, T2;
identifier OBJ, ARG1, ARG2;
@@
void visit_type_enum
-(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp)
+(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
{ ... }
@@
type TV, TErr, TObj;
identifier OBJ;
identifier VISIT_TYPE =~ "^visit_type_";
@@
void VISIT_TYPE
-(TV v, TObj OBJ, const char *name, TErr errp)
+(TV v, const char *name, TObj OBJ, TErr errp)
{ ... }
// Part 2: swap caller order
@@
expression V, NAME, OBJ, ARG1, ARG2, ERR;
identifier VISIT_TYPE =~ "^visit_type_";
@@
(
-visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR)
+visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR)
|
-visit_optional(V, ARG1, NAME)
+visit_optional(V, NAME, ARG1)
|
-visit_get_next_type(V, OBJ, ARG1, NAME, ERR)
+visit_get_next_type(V, NAME, OBJ, ARG1, ERR)
|
-visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR)
+visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR)
|
-VISIT_TYPE(V, OBJ, NAME, ERR)
+VISIT_TYPE(V, NAME, OBJ, ERR)
)
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
No need to repeat 'struct Visitor' when we already have it in
typedefs.h. Omitting the redundant 'struct' also makes a later
patch easier to search for all object property callbacks that
are associated with a Visitor.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-18-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Rework the control flow of balloon_stats_get_all() to make it
easier for a later patch to split visit_end_struct(). Also
switch to the uint64 visitor to match the data type.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The return code of virtqueue_pop/vring_pop is unused except to check for
errors or 0. We can thus easily move allocation inside the functions
and just return a pointer to the VirtQueueElement.
The advantage is that we will be able to allocate only the space that
is needed for the actual size of the s/g list instead of the full
VIRTQUEUE_MAX_SIZE items. Currently VirtQueueElement takes about 48K
of memory, and this kind of allocation puts a lot of stress on malloc.
By cutting the size by two or three orders of magnitude, malloc can
use much more efficient algorithms.
The patch is pretty large, but changes to each device are testable
more or less independently. Splitting it would mostly add churn.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
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: 1453832250-766-15-git-send-email-peter.maydell@linaro.org
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>
Commit ef546f1275 ("virtio: add
feature checking helpers") introduced a helper __virtio_has_feature.
We don't want to use reserved identifiers, though, so let's
rename __virtio_has_feature to virtio_has_feature and virtio_has_feature
to virtio_vdev_has_feature.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Excessive virtio_balloon inflation can cause invocation of OOM-killer,
when Linux is under severe memory pressure. Various mechanisms are
responsible for correct virtio_balloon memory management. Nevertheless it
is often the case that these control tools does not have enough time to
react on fast changing memory load. As a result OS runs out of memory and
invokes OOM-killer. The balancing of memory by use of the virtio balloon
should not cause the termination of processes while there are pages in the
balloon. Now there is no way for virtio balloon driver to free memory at
the last moment before some process get killed by OOM-killer.
This does not provide a security breach as balloon itself is running
inside Guest OS and is working in the cooperation with the host. Thus
some improvements from Guest side should be considered as normal.
To solve the problem, introduce a virtio_balloon callback which is
expected to be called from the oom notifier call chain in out_of_memory()
function. If virtio balloon could release some memory, it will make the
system return and retry the allocation that forced the out of memory
killer to run.
This behavior should be enabled if and only if appropriate feature bit
is set on the device. It is off by default.
This functionality was recently merged into vanilla Linux.
commit 5a10b7dbf904bfe01bb9fcc6298f7df09eed77d5
Author: Raushaniya Maksudova <rmaksudova@parallels.com>
Date: Mon Nov 10 09:36:29 2014 +1030
This patch adds respective control bits into QEMU. It introduces
deflate-on-oom option for balloon device which does the trick.
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Raushaniya Maksudova <rmaksudova@parallels.com>
CC: Anthony Liguori <aliguori@amazon.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: James Bottomley <JBottomley@Odin.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
This was missed during the conversion of feature bit manipulation.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Make features 64bit wide everywhere.
On migration a full 64bit guest_features field is sent if one of the
high bits is set, in addition to the lower 32bit guest_features field
which must stay for compatibility reasons. That way we send the lower
32 feature bits twice, but the code is simpler because we don't have
to split and compose the 64bit features into two 32bit fields.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This is in preparation for using alias property in virtio-balloon-pci
and virtio-balloon-ccw.
Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
A VM supports only one balloon device, but due to several changes
in infrastructure the error message got messed up when trying
to add a second device. Fix it.
Before this fix
Command-line:
qemu-qmp: -device virtio-balloon-pci,id=balloon0: Another balloon device already registered
qemu-qmp: -device virtio-balloon-pci,id=balloon0: Adding balloon handler failed
qemu-qmp: -device virtio-balloon-pci,id=balloon0: Device 'virtio-balloon-pci' could not be initialized
HMP:
Another balloon device already registered
Adding balloon handler failed
Device 'virtio-balloon-pci' could not be initialized
QMP:
{ "execute": "device_add", "arguments": { "driver": "virtio-balloon-pci", "id": "balloon0" } }
{
"error": {
"class": "GenericError",
"desc": "Adding balloon handler failed"
}
}
After this fix
Command-line:
qemu-qmp: -device virtio-balloon-pci,id=balloon0: Only one balloon device is supported
qemu-qmp: -device virtio-balloon-pci,id=balloon0: Device 'virtio-balloon-pci' could not be initialized
HMP:
(qemu) device_add virtio-balloon-pci,id=balloon0
Only one balloon device is supported
Device 'virtio-balloon-pci' could not be initialized
(qemu)
QMP:
{ "execute": "device_add",
"arguments": { "driver": "virtio-balloon-pci", "id": "balloon0" } }
{
"error": {
"class": "GenericError",
"desc": "Only one balloon device is supported"
}
}
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
David Gibson
Peter Maydell
Peter Xu
Alex Williamson
Jonathan Helman
Markus Armbruster
Tomáš Golembiovský
Tiwei Bie
Philippe Mathieu-Daudé
Alistair Francis
Dr. David Alan Gilbert
Ladi Prosek
Halil Pasic
Liang Li
Eric Blake
Paolo Bonzini
Thomas Huth
Pavel Butsykin
Denis V. Lunev
Vladimir Sementsov-Ogievskiy
Cornelia Huck
Jason Wang
Gerd Hoffmann
Shannon Zhao
Luiz Capitulino