18 Dec, 2014
1 commit
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Pull virtio updates from Rusty Russell:
"A balloon enhancement, and a minor race-on-module-unload theoretical
bug which doesn't merit cc: stable.All the exciting stuff went via MST this cycle"
* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
virtio_balloon: free some memory from balloon on OOM
virtio_balloon: return the amount of freed memory from leak_balloon()
virtio_blk: fix race at module removal
virtio: Fix comment typo 'CONFIG_S_FAILED'
15 Dec, 2014
1 commit
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Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev__once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
10 Dec, 2014
12 commits
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kbuild does not seem to like it when we name source
files same as the module.
Let's rename virtio_pci -> virtio_pci_common,
and get rid of #include-ing c files.Signed-off-by: Michael S. Tsirkin
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There's been a lot of changes since 2007.
List main authors, add Red Hat copyright.Signed-off-by: Michael S. Tsirkin
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Move everything dealing with legacy devices out to virtio_pci_legacy.c.
Expose common code APIs in virtio_pci.hSigned-off-by: Michael S. Tsirkin
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config vector setup is version specific, do it indirectly.
Signed-off-by: Michael S. Tsirkin
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VQ setup is mostly version-specific, add another level of indirection to
split the version-independent code out.Signed-off-by: Michael S. Tsirkin
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VQ deletion is mostly version-specific, add another level of indirection
to split the version-independent code out.Signed-off-by: Michael S. Tsirkin
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slightly reduce the amount of pointer chasing this needs to do.
More importantly, this will easily generalize to virtio 1.0.Signed-off-by: Michael S. Tsirkin
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We don't need to go from vq to vq info on
data path, so using direct vq->priv pointer for that
seems like a waste.Let's build an array of vq infos, then we can use vq->index
for that lookup.Signed-off-by: Michael S. Tsirkin
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should be
struct foo {
}not
struct foo
{
}Signed-off-by: Michael S. Tsirkin
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Use isr field instead of direct access to ioaddr.
This way generalizes easily to virtio 1.0.Signed-off-by: Michael S. Tsirkin
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legacy_only flag is now unused, drop it from core.
Signed-off-by: Michael S. Tsirkin
Acked-by: Cornelia Huck -
we have blacklisted balloon in core, no need
for a driver flag.Signed-off-by: Michael S. Tsirkin
Acked-by: Cornelia Huck
09 Dec, 2014
12 commits
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This will make it easy for transports to validate features and return
failure.Signed-off-by: Michael S. Tsirkin
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transports need to be able to detect legacy-only
devices (ATM balloon only) to use legacy path
to drive them.Add a core API to do just that.
The implementation just blacklists balloon:
not too pretty, but let's not over-engineer.Signed-off-by: Michael S. Tsirkin
Acked-by: Cornelia Huck -
Activate VIRTIO_F_VERSION_1 automatically unless legacy_only
is set.Signed-off-by: Michael S. Tsirkin
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We have no plans to support virtio 1.0 in balloon driver. Add an
explicit flag to mark it legacy only.This will be used by follow-up patches.
Signed-off-by: Michael S. Tsirkin
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virtio-blk has some legacy feature bits that modern drivers
must not negotiate, but are needed for old legacy hosts
(that e.g. don't support virtio-scsi).
Allow a separate legacy feature table for such cases.Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck -
Now that we use u64 for bits, we can simply & them together.
Signed-off-by: Michael S. Tsirkin
Reviewed-by: David Hildenbrand
Reviewed-by: Cornelia Huck -
set FEATURES_OK as per virtio 1.0 spec
Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck -
For virtio-1, we can theoretically have a more complex virtqueue
layout with avail and used buffers not on a contiguous memory area
with the descriptor table. For now, it's fine for a transport driver
to stay with the old layout: It needs, however, a way to access
the locations of the avail/used rings so it can register them with
the host.Reviewed-by: David Hildenbrand
Signed-off-by: Cornelia HuckSigned-off-by: Michael S. Tsirkin
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Use virtioXX_to_cpu and friends for access to
all multibyte structures in memory.Note: this is intentionally mechanical.
A follow-up patch will split long lines etc.Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck -
At this point, no transports set any of the high 32 feature bits.
Since transports generally can't (yet) cope with such bits, add BUG_ON
checks to make sure they are not set by mistake.Based on rproc patch by Rusty.
Signed-off-by: Rusty Russell
Signed-off-by: Michael S. Tsirkin
Reviewed-by: David Hildenbrand
Reviewed-by: Cornelia Huck -
Change u32 to u64, and use BIT_ULL and 1ULL everywhere.
Note: transports are unchanged, and only set low 32 bit.
This guarantees that no transport sets e.g. VERSION_1
by mistake without proper support.Based on patch by Rusty.
Signed-off-by: Rusty Russell
Signed-off-by: Cornelia Huck
Signed-off-by: Michael S. Tsirkin
Reviewed-by: David Hildenbrand
Reviewed-by: Cornelia Huck -
It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits. Just change it to a u32 for now.Based on patch by Rusty.
Suggested-by: David Hildenbrand
Signed-off-by: Rusty Russell
Signed-off-by: Cornelia Huck
Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck
11 Nov, 2014
2 commits
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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 some memory at the last moment before some process will be 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 to return and retry the allocation that forced the out of
memory killer to run.Allocate virtio feature bit for this: it is not set by default,
the the guest will not deflate virtio balloon on OOM without explicit
permission from host.Signed-off-by: Raushaniya Maksudova
Signed-off-by: Denis V. Lunev
Acked-by: Michael S. Tsirkin
Signed-off-by: Rusty Russell -
This value would be useful in the next patch to provide the amount of
the freed memory for OOM killer.Signed-off-by: Raushaniya Maksudova
Signed-off-by: Denis V. Lunev
CC: Rusty Russell
CC: Michael S. Tsirkin
Signed-off-by: Rusty Russell
20 Oct, 2014
1 commit
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A platform_driver does not need to set an owner, it will be populated by the
driver core.Signed-off-by: Wolfram Sang
19 Oct, 2014
1 commit
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Pull virtio updates from Rusty Russell:
"One cc: stable commit, the rest are a series of minor cleanups which
have been sitting in MST's tree during my vacation. I changed a
function name and made one trivial change, then they spent two days in
linux-next"* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits)
virtio-rng: refactor probe error handling
virtio_scsi: drop scan callback
virtio_balloon: enable VQs early on restore
virtio_scsi: fix race on device removal
virito_scsi: use freezable WQ for events
virtio_net: enable VQs early on restore
virtio_console: enable VQs early on restore
virtio_scsi: enable VQs early on restore
virtio_blk: enable VQs early on restore
virtio_scsi: move kick event out from virtscsi_init
virtio_net: fix use after free on allocation failure
9p/trans_virtio: enable VQs early
virtio_console: enable VQs early
virtio_blk: enable VQs early
virtio_net: enable VQs early
virtio: add API to enable VQs early
virtio_net: minor cleanup
virtio-net: drop config_mutex
virtio_net: drop config_enable
virtio-blk: drop config_mutex
...
15 Oct, 2014
5 commits
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virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after resume returns, virtio balloon
violated this rule by adding bufs, which causes the VQ to be used
directly within restore.To fix, call virtio_device_ready before using VQ.
Signed-off-by: Michael S. Tsirkin
Signed-off-by: Rusty Russell -
Defer config changed notifications that arrive during
probe/scan/freeze/restore.This will allow drivers to set DRIVER_OK earlier, without worrying about
racing with config change interrupts.This change will also benefit old hypervisors (before 2009)
that send interrupts without checking DRIVER_OK: previously,
the callback could race with driver-specific initialization.This will also help simplify drivers.
Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck
Signed-off-by: Rusty Russell (cosmetic changes) -
This is in preparation to extending config changed event handling
in core.
Wrapping these in an API also seems to make for a cleaner code.Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck
Signed-off-by: Rusty Russell -
Replace duplicated code in all transports with a single wrapper in
virtio.c.The only functional change is in virtio_mmio.c: if a buggy device sends
us an interrupt before driver is set, we previously returned IRQ_NONE,
now we return IRQ_HANDLED.As this must not happen in practice, this does not look like a big deal.
See also commit 3fff0179e33cd7d0a688dab65700c46ad089e934
virtio-pci: do not oops on config change if driver not loaded.
for the original motivation behind the driver check.Signed-off-by: Michael S. Tsirkin
Reviewed-by: Cornelia Huck
Signed-off-by: Rusty Russell -
On restore, virtio pci does the following:
+ set features
+ init vqs etc - device can be used at this point!
+ set ACKNOWLEDGE,DRIVER and DRIVER_OK status bitsThis is in violation of the virtio spec, which
requires the following order:
- ACKNOWLEDGE
- DRIVER
- init vqs
- DRIVER_OKThis behaviour will break with hypervisors that assume spec compliant
behaviour. It seems like a good idea to have this patch applied to
stable branches to reduce the support butden for the hypervisors.Cc: stable@vger.kernel.org
Cc: Amit Shah
Signed-off-by: Michael S. Tsirkin
Signed-off-by: Rusty Russell
10 Oct, 2014
3 commits
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Always mark pages with PageBalloon even if balloon compaction is disabled
and expose this mark in /proc/kpageflags as KPF_BALLOON.Also this patch adds three counters into /proc/vmstat: "balloon_inflate",
"balloon_deflate" and "balloon_migrate". They accumulate balloon
activity. Current size of balloon is (balloon_inflate - balloon_deflate)
pages.All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON.
It should be selected by ballooning driver which wants use this feature.
Currently virtio-balloon is the only user.Signed-off-by: Konstantin Khlebnikov
Cc: Rafael Aquini
Cc: Andrey Ryabinin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now ballooned pages are detected using PageBalloon(). Fake mapping is no
longer required. This patch links ballooned pages to balloon device using
field page->private instead of page->mapping. Also this patch embeds
balloon_dev_info directly into struct virtio_balloon.Signed-off-by: Konstantin Khlebnikov
Cc: Rafael Aquini
Cc: Andrey Ryabinin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Sasha Levin reported KASAN splash inside isolate_migratepages_range().
Problem is in the function __is_movable_balloon_page() which tests
AS_BALLOON_MAP in page->mapping->flags. This function has no protection
against anonymous pages. As result it tried to check address space flags
inside struct anon_vma.Further investigation shows more problems in current implementation:
* Special branch in __unmap_and_move() never works:
balloon_page_movable() checks page flags and page_count. In
__unmap_and_move() page is locked, reference counter is elevated, thus
balloon_page_movable() always fails. As a result execution goes to the
normal migration path. virtballoon_migratepage() returns
MIGRATEPAGE_BALLOON_SUCCESS instead of MIGRATEPAGE_SUCCESS,
move_to_new_page() thinks this is an error code and assigns
newpage->mapping to NULL. Newly migrated page lose connectivity with
balloon an all ability for further migration.* lru_lock erroneously required in isolate_migratepages_range() for
isolation ballooned page. This function releases lru_lock periodically,
this makes migration mostly impossible for some pages.* balloon_page_dequeue have a tight race with balloon_page_isolate:
balloon_page_isolate could be executed in parallel with dequeue between
picking page from list and locking page_lock. Race is rare because they
use trylock_page() for locking.This patch fixes all of them.
Instead of fake mapping with special flag this patch uses special state of
page->_mapcount: PAGE_BALLOON_MAPCOUNT_VALUE = -256. Buddy allocator uses
PAGE_BUDDY_MAPCOUNT_VALUE = -128 for similar purpose. Storing mark
directly in struct page makes everything safer and easier.PagePrivate is used to mark pages present in page list (i.e. not
isolated, like PageLRU for normal pages). It replaces special rules for
reference counter and makes balloon migration similar to migration of
normal pages. This flag is protected by page_lock together with link to
the balloon device.Signed-off-by: Konstantin Khlebnikov
Reported-by: Sasha Levin
Link: http://lkml.kernel.org/p/53E6CEAA.9020105@oracle.com
Cc: Rafael Aquini
Cc: Andrey Ryabinin
Cc: [3.8+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Sep, 2014
2 commits
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virtqueue_add() populates the virtqueue descriptor table from the sgs
given. If it uses an indirect descriptor table, then it puts a single
descriptor in the descriptor table pointing to the kmalloc'ed indirect
table where the sg is populated.Previously vring_add_indirect() did the allocation and the simple
linear layout. We replace that with alloc_indirect() which allocates
the indirect table then chains it like the normal descriptor table so
we can reuse the core logic.This slows down pktgen by less than 1/2 a percent (which uses direct
descriptors), as well as vring_bench, but it's far neater.vring_bench before:
1061485790-1104800648(1.08254e+09+/-6.6e+06)ns
vring_bench after:
1125610268-1183528965(1.14172e+09+/-8e+06)nspktgen before:
787781-796334(793165+/-2.4e+03)pps 365-369(367.5+/-1.2)Mb/sec (365530384-369498976(3.68028e+08+/-1.1e+06)bps) errors: 0pktgen after:
779988-790404(786391+/-2.5e+03)pps 361-366(364.35+/-1.3)Mb/sec (361914432-366747456(3.64885e+08+/-1.2e+06)bps) errors: 0Now, if we make force indirect descriptors by turning off any_header_sg
in virtio_net.c:pktgen before:
713773-721062(718374+/-2.1e+03)pps 331-334(332.95+/-0.92)Mb/sec (331190672-334572768(3.33325e+08+/-9.6e+05)bps) errors: 0
pktgen after:
710542-719195(714898+/-2.4e+03)pps 329-333(331.15+/-1.1)Mb/sec (329691488-333706480(3.31713e+08+/-1.1e+06)bps) errors: 0Signed-off-by: Rusty Russell
Signed-off-by: David S. Miller -
We used to have several callers which just used arrays. They're
gone, so we can use sg_next() everywhere, simplifying the code.On my laptop, this slowed down vring_bench by 15%:
vring_bench before:
936153354-967745359(9.44739e+08+/-6.1e+06)ns
vring_bench after:
1061485790-1104800648(1.08254e+09+/-6.6e+06)nsHowever, a more realistic test using pktgen on a AMD FX(tm)-8320 saw
a few percent improvement:pktgen before:
767390-792966(785159+/-6.5e+03)pps 356-367(363.75+/-2.9)Mb/sec (356068960-367936224(3.64314e+08+/-3e+06)bps) errors: 0pktgen after:
787781-796334(793165+/-2.4e+03)pps 365-369(367.5+/-1.2)Mb/sec (365530384-369498976(3.68028e+08+/-1.1e+06)bps) errors: 0Signed-off-by: Rusty Russell
Signed-off-by: David S. Miller
