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2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-08lib/interval_tree: fast overlap detectionDavidlohr Bueso
Allow interval trees to quickly check for overlaps to avoid unnecesary tree lookups in interval_tree_iter_first(). As of this patch, all interval tree flavors will require using a 'rb_root_cached' such that we can have the leftmost node easily available. While most users will make use of this feature, those with special functions (in addition to the generic insert, delete, search calls) will avoid using the cached option as they can do funky things with insertions -- for example, vma_interval_tree_insert_after(). [jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()] Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: David Airlie <airlied@linux.ie> Cc: Jason Wang <jasowang@redhat.com> Cc: Christian Benvenuti <benve@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-29Revert "vhost: cache used event for better performance"Jason Wang
This reverts commit 809ecb9bca6a9424ccd392d67e368160f8b76c92. Since it was reported to break vhost_net. We want to cache used event and use it to check for notification. The assumption was that guest won't move the event idx back, but this could happen in fact when 16 bit index wraps around after 64K entries. Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02vhost: introduce O(1) vq metadata cacheJason Wang
When device IOTLB is enabled, all address translations were stored in interval tree. O(lgN) searching time could be slow for virtqueue metadata (avail, used and descriptors) since they were accessed much often than other addresses. So this patch introduces an O(1) array which points to the interval tree nodes that store the translations of vq metadata. Those array were update during vq IOTLB prefetching and were reset during each invalidation and tlb update. Each time we want to access vq metadata, this small array were queried before interval tree. This would be sufficient for static mappings but not dynamic mappings, we could do optimizations on top. Test were done with l2fwd in guest (2M hugepage): noiommu | before | after tx 1.32Mpps | 1.06Mpps(82%) | 1.30Mpps(98%) rx 2.33Mpps | 1.46Mpps(63%) | 2.29Mpps(98%) We can almost reach the same performance as noiommu mode. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-12-16vhost: cache used event for better performanceJason Wang
When event index was enabled, we need to fetch used event from userspace memory each time. This userspace fetch (with memory barrier) could be saved sometime when 1) caching used event and 2) if used event is ahead of new and old to new updating does not cross it, we're sure there's no need to notify guest. This will be useful for heavy tx load e.g guest pktgen test with Linux driver shows ~3.5% improvement. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-02vhost: new device IOTLB APIJason Wang
This patch tries to implement an device IOTLB for vhost. This could be used with userspace(qemu) implementation of DMA remapping to emulate an IOMMU for the guest. The idea is simple, cache the translation in a software device IOTLB (which is implemented as an interval tree) in vhost and use vhost_net file descriptor for reporting IOTLB miss and IOTLB update/invalidation. When vhost meets an IOTLB miss, the fault address, size and access can be read from the file. After userspace finishes the translation, it writes the translated address to the vhost_net file to update the device IOTLB. When device IOTLB is enabled by setting VIRTIO_F_IOMMU_PLATFORM all vq addresses set by ioctl are treated as iova instead of virtual address and the accessing can only be done through IOTLB instead of direct userspace memory access. Before each round or vq processing, all vq metadata is prefetched in device IOTLB to make sure no translation fault happens during vq processing. In most cases, virtqueues are contiguous even in virtual address space. The IOTLB translation for virtqueue itself may make it a little slower. We might add fast path cache on top of this patch. Signed-off-by: Jason Wang <jasowang@redhat.com> [mst: use virtio feature bit: VHOST_F_DEVICE_IOTLB -> VIRTIO_F_IOMMU_PLATFORM ] [mst: fix build warnings ] Signed-off-by: Michael S. Tsirkin <mst@redhat.com> [ weiyj.lk: missing unlock on error ] Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
2016-08-02vhost: convert pre sorted vhost memory array to interval treeJason Wang
Current pre-sorted memory region array has some limitations for future device IOTLB conversion: 1) need extra work for adding and removing a single region, and it's expected to be slow because of sorting or memory re-allocation. 2) need extra work of removing a large range which may intersect several regions with different size. 3) need trick for a replacement policy like LRU To overcome the above shortcomings, this patch convert it to interval tree which can easily address the above issue with almost no extra work. The patch could be used for: - Extend the current API and only let the userspace to send diffs of memory table. - Simplify Device IOTLB implementation. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-01vhost: lockless enqueuingJason Wang
We use spinlock to synchronize the work list now which may cause unnecessary contentions. So this patch switch to use llist to remove this contention. Pktgen tests shows about 5% improvement: Before: ~1300000 pps After: ~1370000 pps 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>
2016-03-11vhost_net: basic polling supportJason Wang
This patch tries to poll for new added tx buffer or socket receive queue for a while at the end of tx/rx processing. The maximum time spent on polling were specified through a new kind of vring ioctl. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-11vhost: introduce vhost_vq_avail_empty()Jason Wang
This patch introduces a helper which will return true if we're sure that the available ring is empty for a specific vq. When we're not sure, e.g vq access failure, return false instead. This could be used for busy polling code to exit the busy loop. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-11vhost: introduce vhost_has_work()Jason Wang
This path introduces a helper which can give a hint for whether or not there's a work queued in the work list. This could be used for busy polling code to exit the busy loop. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-02vhost: rename vhost_init_used()Greg Kurz
Looking at how callers use this, maybe we should just rename init_used to vhost_vq_init_access. The _used suffix was a hint that we access the vq used ring. But maybe what callers care about is that it must be called after access_ok. Also, this function manipulates the vq->is_le field which isn't related to the vq used ring. This patch simply renames vhost_init_used() to vhost_vq_init_access() as suggested by Michael. No behaviour change. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-27vhost: fix performance on LE hostsMichael S. Tsirkin
commit 2751c9882b947292fcfb084c4f604e01724af804 ("vhost: cross-endian support for legacy devices") introduced a minor regression: even with cross-endian disabled, and even on LE host, vhost_is_little_endian is checking is_le flag so there's always a branch. To fix, simply check virtio_legacy_is_little_endian first. Cc: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-16vhost: move features to coreMichael S. Tsirkin
virtio 1 and any layout are core features, move them there. This fixes vhost test. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-01vhost: cross-endian support for legacy devicesGreg Kurz
This patch brings cross-endian support to vhost when used to implement legacy virtio devices. Since it is a relatively rare situation, the feature availability is controlled by a kernel config option (not set by default). The vq->is_le boolean field is added to cache the endianness to be used for ring accesses. It defaults to native endian, as expected by legacy virtio devices. When the ring gets active, we force little endian if the device is modern. When the ring is deactivated, we revert to the native endian default. If cross-endian was compiled in, a vq->user_be boolean field is added so that userspace may request a specific endianness. This field is used to override the default when activating the ring of a legacy device. It has no effect on modern devices. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2015-06-01virtio: add explicit big-endian support to memory accessorsGreg Kurz
The current memory accessors logic is: - little endian if little_endian - native endian (i.e. no byteswap) if !little_endian If we want to fully support cross-endian vhost, we also need to be able to convert to big endian. Instead of changing the little_endian argument to some 3-value enum, this patch changes the logic to: - little endian if little_endian - big endian if !little_endian The native endian case is handled by all users with a trivial helper. This patch doesn't change any functionality, nor it does add overhead. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2015-06-01vhost: introduce vhost_is_little_endian() helperGreg Kurz
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2014-12-09vhost: remove unnecessary forward declarations in vhost.hJason Wang
Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09vhost: add memory access wrappersMichael S. Tsirkin
Add guest memory access wrappers to handle virtio endianness conversions. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09vhost: make features 64 bitMichael S. Tsirkin
We need to use bit 32 for virtio 1.0. Make vhost_has_feature bool to avoid discarding high bits. Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com>
2014-06-09vhost: move memory pointer to VQsMichael S. Tsirkin
commit 2ae76693b8bcabf370b981cd00c36cd41d33fabc vhost: replace rcu with mutex replaced rcu sync for memory accesses with VQ mutex locl/unlock. This is correct since all accesses are under VQ mutex, but incomplete: we still do useless rcu lock/unlock operations, someone might copy this code into some other context where this won't be right. This use of RCU is also non standard and hard to understand. Let's copy the pointer to each VQ structure, this way the access rules become straight-forward, and there's no need for RCU anymore. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-09vhost: move acked_features to VQsMichael S. Tsirkin
Refactor code to make sure features are only accessed under VQ mutex. This makes everything simpler, no need for RCU here anymore. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-12-06vhost: remove the dead branchZhi Yong Wu
Since vhost_dev_init() forever return 0, some branches are never run, therefore need to be removed. Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-11vhost: Remove custom vhost rcu usageAsias He
Now, vq->private_data is always accessed under vq mutex. No need to play the vhost rcu trick. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-07-07vhost: Make vhost a separate moduleAsias He
Currently, vhost-net and vhost-scsi are sharing the vhost core code. However, vhost-scsi shares the code by including the vhost.c file directly. Making vhost a separate module makes it is easier to share code with other vhost devices. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-06-11vhost: check owner before we overwrite ubuf_infoMichael S. Tsirkin
If device has an owner, we shouldn't touch ubuf_info since it might be in use. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-06vhost: Remove vhost_enable_zcopy in vhost.hAsias He
It is net.c specific. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-06vhost: Remove comments for hdr in vhost.hAsias He
It is supposed to be removed when hdr is moved into vhost_net_virtqueue. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-06vhost: Move VHOST_NET_FEATURES to net.cAsias He
vhost.h should not depend on device specific marcos like VHOST_NET_F_VIRTIO_NET_HDR and VIRTIO_NET_F_MRG_RXBUF. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-06vhost: Export vhost_dev_set_ownerAsias He
Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01vhost: fix error handling in RESET_OWNER ioctlMichael S. Tsirkin
RESET_OWNER ioctl would leave the fd in a bad state if memory allocation failed: device is stopped but owner is not reset. Make state changes after allocating memory, such that a failed ioctl has no effect. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01vhost: move per-vq net specific fields out to netMichael S. Tsirkin
This will remove the need for vhost scsi to pull in virtio-net.h. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01vhost: move vhost-net zerocopy fields to net.cAsias He
On top of 'vhost: Allow device specific fields per vq', we can move device specific fields to device virt queue from vhost virt queue. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-05-01vhost: Allow device specific fields per vqAsias He
This is useful for any device who wants device specific fields per vq. For example, tcm_vhost wants a per vq field to track requests which are in flight on the vq. Also, on top of this we can add patches to move things like ubufs from vhost.h out to net.c. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-01-29vhost_net: handle polling errors when setting backendJason Wang
Currently, the polling errors were ignored, which can lead following issues: - vhost remove itself unconditionally from waitqueue when stopping the poll, this may crash the kernel since the previous attempt of starting may fail to add itself to the waitqueue - userspace may think the backend were successfully set even when the polling failed. Solve this by: - check poll->wqh before trying to remove from waitqueue - report polling errors in vhost_poll_start(), tx_poll_start(), the return value will be checked and returned when userspace want to set the backend After this fix, there still could be a polling failure after backend is set, it will addressed by the next patch. Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-06vhost: avoid backend flush on vring opsMichael S. Tsirkin
vring changes already do a flush internally where appropriate, so we do not need a second flush. It's currently not very expensive but a follow-up patch makes flush more heavy-weight, so remove the extra flush here to avoid regressing performance if call or kick fds are changed on data path. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-11-02vhost: move -net specific code outMichael S. Tsirkin
Zerocopy handling code is vhost-net specific. Move it from vhost.c/vhost.h out to net.c Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02vhost: track zero copy failures using DMA lengthMichael S. Tsirkin
This will be used to disable zerocopy when error rate is high. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02vhost-net: cleanup macros for DMA status trackingMichael S. Tsirkin
Better document macros for DMA tracking. Add an explicit one for DMA in progress instead of relying on user supplying len != 1. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-02skb: report completion status for zero copy skbsMichael S. Tsirkin
Even if skb is marked for zero copy, net core might still decide to copy it later which is somewhat slower than a copy in user context: besides copying the data we need to pin/unpin the pages. Add a parameter reporting such cases through zero copy callback: if this happens a lot, device can take this into account and switch to copying in user context. This patch updates all users but ignores the passed value for now: it will be used by follow-up patches. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-22vhost: make vhost work queue visibleStefan Hajnoczi
The vhost work queue allows processing to be done in vhost worker thread context, which uses the owner process mm. Access to the vring and guest memory is typically only possible from vhost worker context so it is useful to allow work to be queued directly by users. Currently vhost_net only uses the poll wrappers which do not expose the work queue functions. However, for tcm_vhost (vhost_scsi) it will be necessary to queue custom work. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Cc: Zhi Yong Wu <wuzhy@cn.ibm.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-07-22vhost: Separate vhost-net features from vhost featuresStefan Hajnoczi
In order for other vhost devices to use the VHOST_FEATURES bits the vhost-net specific bits need to be moved to their own VHOST_NET_FEATURES constant. (Asias: Update drivers/vhost/test.c to use VHOST_NET_FEATURES) Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Cc: Zhi Yong Wu <wuzhy@cn.ibm.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Asias He <asias@redhat.com> Signed-off-by: Nicholas A. Bellinger <nab@risingtidesystems.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-13skbuff: struct ubuf_info callback type safetyMichael S. Tsirkin
The skb struct ubuf_info callback gets passed struct ubuf_info itself, not the arg value as the field name and the function signature seem to imply. Rename the arg field to ctx to match usage, add documentation and change the callback argument type to make usage clear and to have compiler check correctness. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-28vhost: fix release path lockdep checksMichael S. Tsirkin
We shouldn't hold any locks on release path. Pass a flag to vhost_dev_cleanup to use the lockdep info correctly. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Sasha Levin <levinsasha928@gmail.com>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-19vhost: init used ring after backend was setJason Wang
Move the used ring initialization after backend was set. This makes it possible to disable the backend and tweak the used ring, then restart. This will also make it possible to log the used ring write correctly. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-18vhost: vhost TX zero-copy supportMichael S. Tsirkin
>From: Shirley Ma <mashirle@us.ibm.com> This adds experimental zero copy support in vhost-net, disabled by default. To enable, set experimental_zcopytx module option to 1. This patch maintains the outstanding userspace buffers in the sequence it is delivered to vhost. The outstanding userspace buffers will be marked as done once the lower device buffers DMA has finished. This is monitored through last reference of kfree_skb callback. Two buffer indices are used for this purpose. The vhost-net device passes the userspace buffers info to lower device skb through message control. DMA done status check and guest notification are handled by handle_tx: in the worst case is all buffers in the vq are in pending/done status, so we need to notify guest to release DMA done buffers first before we get any new buffers from the vq. One known problem is that if the guest stops submitting buffers, buffers might never get used until some further action, e.g. device reset. This does not seem to affect linux guests. Signed-off-by: Shirley <xma@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-30vhost: support event indexMichael S. Tsirkin
Support the new event index feature. When acked, utilize it to reduce the # of interrupts sent to the guest. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-02-01vhost: rcu annotation fixupMichael S. Tsirkin
When built with rcu checks enabled, vhost triggers bogus warnings as vhost features are read without dev->mutex sometimes, and private pointer is read with our kind of rcu where work serves as a read side critical section. Fixing it properly is not trivial. Disable the warnings by stubbing out the checks for now. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>