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* virtio_pci: document why we defer kfreeMichael S. Tsirkin2015-01-061-0/+3
| | | | | | | | | | | | | The reason we defer kfree until release function is because it's a general rule for kobjects: kfree of the reference counter itself is only legal in the release function. Previous patch didn't make this clear, document this in code. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_pci: defer kfree until release callbackSasha Levin2015-01-061-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | A struct device which has just been unregistered can live on past the point at which a driver decides to drop it's initial reference to the kobject gained on allocation. This implies that when releasing a virtio device, we can't free a struct virtio_device until the underlying struct device has been released, which might not happen immediately on device_unregister(). Unfortunately, this is exactly what virtio pci does: it has an empty release callback, and frees memory immediately after unregistering the device. This causes an easy to reproduce crash if CONFIG_DEBUG_KOBJECT_RELEASE it enabled. To fix, free the memory only once we know the device is gone in the release callback. Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_pci: device-specific release callbackMichael S. Tsirkin2015-01-063-10/+9
| | | | | | | | | It turns out we need to add device-specific code in release callback. Move it to virtio_pci_legacy.c. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: make del_vqs idempotentMichael S. Tsirkin2015-01-061-0/+1
| | | | | | | | | | | | | | | | | | Our code calls del_vqs multiple times, assuming it's idempotent. commit 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 virtio_pci: free up vq->priv broke this assumption, by adding kfree there, so multiple calls cause double free. Fix it up. Fixes: 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds2014-12-184-41/+66
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull virtio fixes from Michael S Tsirkin: "virtio 1.0 related fixes Most importantly, this fixes using virtio_pci as a module. Further, the big virtio 1.0 conversion missed a couple of places. This fixes them up. This isn't 100% sparse-clean yet because on many architectures get_user triggers sparse warnings when used with __bitwise tag (when same tag is on both pointer and value read). I posted a patchset to fix it up by adding __force on all arches that don't already have it (many do), when that's merged these warnings will go away" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio_pci: restore module attributes mic/host: fix up virtio 1.0 APIs vringh: update for virtio 1.0 APIs vringh: 64 bit features tools/virtio: add virtio 1.0 in vringh_test tools/virtio: add virtio 1.0 in virtio_test tools/virtio: enable -Werror tools/virtio: 64 bit features tools/virtio: fix vringh test tools/virtio: more stubs virtio: core support for config generation virtio_pci: add VIRTIO_PCI_NO_LEGACY virtio_pci: move probe to common file virtio_pci_common.h: drop VIRTIO_PCI_NO_LEGACY virtio_config: fix virtio_cread_bytes virtio: set VIRTIO_CONFIG_S_FEATURES_OK on restore
| * virtio_pci: restore module attributesHerbert Xu2014-12-171-0/+5
| | | | | | | | | | | | | | | | When the virtio_pci driver was moved into virtio_pci_legacy.c the module licence and other attributes went AWOL. This patch restores them. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * virtio_pci: move probe to common fileMichael S. Tsirkin2014-12-143-26/+38
| | | | | | | | | | | | It turns out this make everything easier. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * virtio_pci_common.h: drop VIRTIO_PCI_NO_LEGACYMichael S. Tsirkin2014-12-111-1/+0
| | | | | | | | | | | | | | Legacy drivers use virtio_pci_common.h too, we should not define VIRTIO_PCI_NO_LEGACY there. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * virtio: set VIRTIO_CONFIG_S_FEATURES_OK on restoreMichael S. Tsirkin2014-12-111-14/+23
| | | | | | | | | | | | | | | | | | virtio 1.0 devices require that drivers set VIRTIO_CONFIG_S_FEATURES_OK after finalizing features. virtio core missed doing this on restore, fix it up. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds2014-12-171-1/+56
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 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'
| * | virtio_balloon: free some memory from balloon on OOMRaushaniya Maksudova2014-11-111-0/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rmaksudova@parallels.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | virtio_balloon: return the amount of freed memory from leak_balloon()Raushaniya Maksudova2014-11-111-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rmaksudova@parallels.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | | Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds2014-12-141-1/+0
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 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_<level>_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 ...
| * | virtio: drop owner assignment from platform_driversWolfram Sang2014-10-201-1/+0
| |/ | | | | | | | | | | | | A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* | virtio_pci: rename virtio_pci -> virtio_pci_commonMichael S. Tsirkin2014-12-094-4/+5
| | | | | | | | | | | | | | | | | | 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 <mst@redhat.com>
* | virtio_pci: update file descriptions and copyrightMichael S. Tsirkin2014-12-093-3/+12
| | | | | | | | | | | | | | There's been a lot of changes since 2007. List main authors, add Red Hat copyright. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_pci: split out legacy device supportMichael S. Tsirkin2014-12-093-408/+468
| | | | | | | | | | | | | | Move everything dealing with legacy devices out to virtio_pci_legacy.c. Expose common code APIs in virtio_pci.h Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_pci: setup config vector indirectlyMichael S. Tsirkin2014-12-091-6/+13
| | | | | | | | | | | | config vector setup is version specific, do it indirectly. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_pci: setup vqs indirectlyMichael S. Tsirkin2014-12-091-23/+46
| | | | | | | | | | | | | | VQ setup is mostly version-specific, add another level of indirection to split the version-independent code out. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_pci: delete vqs indirectlyMichael S. Tsirkin2014-12-091-7/+20
| | | | | | | | | | | | | | VQ deletion is mostly version-specific, add another level of indirection to split the version-independent code out. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_pci: use priv for vq notificationMichael S. Tsirkin2014-12-091-3/+2
| | | | | | | | | | | | | | 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 <mst@redhat.com>
* | virtio_pci: free up vq->privMichael S. Tsirkin2014-12-091-25/+31
| | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com>
* | virtio_pci: fix coding style for structsMichael S. Tsirkin2014-12-091-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | should be struct foo { } not struct foo { } Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_pci: add isr fieldMichael S. Tsirkin2014-12-091-1/+6
| | | | | | | | | | | | | | Use isr field instead of direct access to ioaddr. This way generalizes easily to virtio 1.0. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio: drop legacy_only driver flagMichael S. Tsirkin2014-12-091-4/+0
| | | | | | | | | | | | | | legacy_only flag is now unused, drop it from core. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio_balloon: drop legacy_only driver flagMichael S. Tsirkin2014-12-091-1/+0
| | | | | | | | | | | | | | | | | | we have blacklisted balloon in core, no need for a driver flag. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: allow finalize_features to failMichael S. Tsirkin2014-12-093-9/+20
| | | | | | | | | | | | | | This will make it easy for transports to validate features and return failure. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio: add API to detect legacy devicesMichael S. Tsirkin2014-12-091-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: make VIRTIO_F_VERSION_1 a transport bitMichael S. Tsirkin2014-12-092-1/+7
| | | | | | | | | | | | | | | | | | | | | | Activate VIRTIO_F_VERSION_1 automatically unless legacy_only is set. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_balloon: add legacy_only flagMichael S. Tsirkin2014-12-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com>
* | virtio: add legacy feature table supportMichael S. Tsirkin2014-12-091-1/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: simplify feature bit handlingMichael S. Tsirkin2014-12-091-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | Now that we use u64 for bits, we can simply & them together. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: set FEATURES_OKMichael S. Tsirkin2014-12-091-7/+22
| | | | | | | | | | | | | | | | | | | | | | set FEATURES_OK as per virtio 1.0 spec Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: allow transports to get avail/used addressesCornelia Huck2014-12-091-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <dahi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | virtio_ring: switch to new memory access APIsMichael S. Tsirkin2014-12-091-44/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: assert 32 bit features in transportsMichael S. Tsirkin2014-12-092-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rusty@rustcorp.com.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: add support for 64 bit features.Michael S. Tsirkin2014-12-093-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rusty@rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* | virtio: use u32, not bitmap for featuresMichael S. Tsirkin2014-12-094-14/+9
|/ | | | | | | | | | | | | | | | | | | 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 <dahi@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds2014-10-184-35/+110
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 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 ...
| * virtio_balloon: enable VQs early on restoreMichael S. Tsirkin2014-10-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * virtio: defer config changed notificationsMichael S. Tsirkin2014-10-151-9/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cosmetic changes)
| * virtio-pci: move freeze/restore to virtio coreMichael S. Tsirkin2014-10-152-52/+56
| | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * virtio: unify config_changed handlingMichael S. Tsirkin2014-10-153-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * virtio_pci: fix virtio spec compliance on restoreMichael S. Tsirkin2014-10-151-3/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 bits This is in violation of the virtio spec, which requires the following order: - ACKNOWLEDGE - DRIVER - init vqs - DRIVER_OK This 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 <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | mm/balloon_compaction: add vmstat counters and kpageflags bitKonstantin Khlebnikov2014-10-092-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <k.khlebnikov@samsung.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/balloon_compaction: remove balloon mapping and flag AS_BALLOON_MAPKonstantin Khlebnikov2014-10-091-47/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 <k.khlebnikov@samsung.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/balloon_compaction: redesign ballooned pages managementKonstantin Khlebnikov2014-10-091-8/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <k.khlebnikov@samsung.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Link: http://lkml.kernel.org/p/53E6CEAA.9020105@oracle.com Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: <stable@vger.kernel.org> [3.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | virtio_ring: unify direct/indirect code paths.Rusty Russell2014-09-131-76/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)ns pktgen 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: 0 pktgen 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: 0 Now, 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: 0 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* | virtio_ring: assume sgs are always well-formed.Rusty Russell2014-09-131-49/+19
|/ | | | | | | | | | | | | | | | | | | | | | | | 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)ns However, 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: 0 pktgen 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: 0 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* virtio: Replace DEFINE_PCI_DEVICE_TABLE macro useBenoit Taine2014-07-271-1/+1
| | | | | | | | We should prefer `struct pci_device_id` over `DEFINE_PCI_DEVICE_TABLE` to meet kernel coding style guidelines. This issue was reported by checkpatch. Signed-off-by: Benoit Taine <benoit.taine@lip6.fr> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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