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* vhost: Fix the calculation in vhost_overflow()Xie Yongji2021-08-111-2/+8
| | | | | | | | | | | | This fixes the incorrect calculation for integer overflow when the last address of iova range is 0xffffffff. Fixes: ec33d031a14b ("vhost: detect 32 bit integer wrap around") Reported-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210728130756.97-2-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: remove work arg from vhost_work_flushMike Christie2021-07-031-4/+4
| | | | | | | | | | | | | | vhost_work_flush doesn't do anything with the work arg. This patch drops it and then renames vhost_work_flush to vhost_work_dev_flush to reflect that the function flushes all the works in the dev and not just a specific queue or work item. Signed-off-by: Mike Christie <michael.christie@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Link: https://lore.kernel.org/r/20210525174733.6212-2-michael.christie@oracle.com Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: Fix vhost_vq_reset()Laurent Vivier2021-03-141-1/+1
| | | | | | | | | | | | | | | | | | | | | vhost_reset_is_le() is vhost_init_is_le(), and in the case of cross-endian legacy, vhost_init_is_le() depends on vq->user_be. vq->user_be is set by vhost_disable_cross_endian(). But in vhost_vq_reset(), we have: vhost_reset_is_le(vq); vhost_disable_cross_endian(vq); And so user_be is used before being set. To fix that, reverse the lines order as there is no other dependency between them. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Link: https://lore.kernel.org/r/20210312140913.788592-1-lvivier@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: add helper to check if a vq has been setupMike Christie2020-11-151-0/+6
| | | | | | | | | | | | | | This adds a helper check if a vq has been setup. The next patches will use this when we move the vhost scsi cmd preallocation from per session to per vq. In the per vq case, we only want to allocate cmds for vqs that have actually been setup and not for all the possible vqs. Signed-off-by: Mike Christie <michael.christie@oracle.com> Link: https://lore.kernel.org/r/1604986403-4931-2-git-send-email-michael.christie@oracle.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
* vhost_vdpa: remove unnecessary spin_lock in vhost_vring_callZhu Lingshan2020-10-211-3/+0
| | | | | | | | | | | | This commit removed unnecessary spin_locks in vhost_vring_call and related operations. Because we manipulate irq offloading contents in vhost_vdpa ioctl code path which is already protected by dev mutex and vq mutex. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Link: https://lore.kernel.org/r/20200909065234.3313-1-lingshan.zhu@intel.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
* vhost: reduce stack usage in log_usedLi Wang2020-10-211-1/+1
| | | | | | | | | | | | | Fix the warning: [-Werror=-Wframe-larger-than=] drivers/vhost/vhost.c: In function log_used: drivers/vhost/vhost.c:1906:1: warning: the frame size of 1040 bytes is larger than 1024 bytes Signed-off-by: Li Wang <li.wang@windriver.com> Link: https://lore.kernel.org/r/1600106889-25013-1-git-send-email-li.wang@windriver.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
* vhost: Don't call log_access_ok() when using IOTLBGreg Kurz2020-10-041-5/+18
| | | | | | | | | | | | | | | | | | When the IOTLB device is enabled, the log_guest_addr that is passed by userspace to the VHOST_SET_VRING_ADDR ioctl, and which is then written to vq->log_addr, is a GIOVA. All writes to this address are translated by log_user() to writes to an HVA, and then ultimately logged through the corresponding GPAs in log_write_hva(). No logging will ever occur with vq->log_addr in this case. It is thus wrong to pass vq->log_addr and log_guest_addr to log_access_vq() which assumes they are actual GPAs. Introduce a new vq_log_used_access_ok() helper that only checks accesses to the log for the used structure when there isn't an IOTLB device around. Signed-off-by: Greg Kurz <groug@kaod.org> Link: https://lore.kernel.org/r/160171933385.284610.10189082586063280867.stgit@bahia.lan Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: Use vhost_get_used_size() in vhost_vring_set_addr()Greg Kurz2020-10-041-2/+1
| | | | | | | | | | | | The open-coded computation of the used size doesn't take the event into account when the VIRTIO_RING_F_EVENT_IDX feature is present. Fix that by using vhost_get_used_size(). Fixes: 8ea8cf89e19a ("vhost: support event index") Cc: stable@vger.kernel.org Signed-off-by: Greg Kurz <groug@kaod.org> Link: https://lore.kernel.org/r/160171932300.284610.11846106312938909461.stgit@bahia.lan Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: Don't call access_ok() when using IOTLBGreg Kurz2020-10-041-4/+5
| | | | | | | | | | | | | | | | | | | | | When the IOTLB device is enabled, the vring addresses we get from userspace are GIOVAs. It is thus wrong to pass them down to access_ok() which only takes HVAs. Access validation is done at prefetch time with IOTLB. Teach vq_access_ok() about that by moving the (vq->iotlb) check from vhost_vq_access_ok() to vq_access_ok(). This prevents vhost_vring_set_addr() to fail when verifying the accesses. No behavior change for vhost_vq_access_ok(). BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1883084 Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") Cc: jasowang@redhat.com CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/160171931213.284610.2052489816407219136.stgit@bahia.lan Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: fix typo in error messageYunsheng Lin2020-09-011-1/+1
| | | | | | | | | | "enable" should be "disable" when the function name is vhost_disable_notify(), which does the disabling work. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds2020-08-111-7/+32
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull virtio updates from Michael Tsirkin: - IRQ bypass support for vdpa and IFC - MLX5 vdpa driver - Endianness fixes for virtio drivers - Misc other fixes * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (71 commits) vdpa/mlx5: fix up endian-ness for mtu vdpa: Fix pointer math bug in vdpasim_get_config() vdpa/mlx5: Fix pointer math in mlx5_vdpa_get_config() vdpa/mlx5: fix memory allocation failure checks vdpa/mlx5: Fix uninitialised variable in core/mr.c vdpa_sim: init iommu lock virtio_config: fix up warnings on parisc vdpa/mlx5: Add VDPA driver for supported mlx5 devices vdpa/mlx5: Add shared memory registration code vdpa/mlx5: Add support library for mlx5 VDPA implementation vdpa/mlx5: Add hardware descriptive header file vdpa: Modify get_vq_state() to return error code net/vdpa: Use struct for set/get vq state vdpa: remove hard coded virtq num vdpasim: support batch updating vhost-vdpa: support IOTLB batching hints vhost-vdpa: support get/set backend features vhost: generialize backend features setting/getting vhost-vdpa: refine ioctl pre-processing vDPA: dont change vq irq after DRIVER_OK ...
| * vhost: generialize backend features setting/gettingJason Wang2020-08-051-0/+15
| | | | | | | | | | | | | | | | | | Move the backend features setting/getting from net.c to vhost.c to be reused by vhost-vdpa. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200804162048.22587-3-eli@mellanox.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: introduce vhost_vring_callZhu Lingshan2020-08-051-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | This commit introduces struct vhost_vring_call which replaced raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue. Besides eventfd_ctx, it contains a spin lock and an irq_bypass_producer in its structure. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Suggested-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200731065533.4144-2-lingshan.zhu@intel.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: Use flex_array_size() helper in copy_from_user()Gustavo A. R. Silva2020-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Make use of the flex_array_size() helper to calculate the size of a flexible array member within an enclosing structure. This helper offers defense-in-depth against potential integer overflows, while at the same time makes it explicitly clear that we are dealing with a flexible array member. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200731130956.GA30525@embeddedor Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | vhost: Remove redundant use of read_barrier_depends() barrierWill Deacon2020-07-211-5/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 76ebbe78f739 ("locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()"), there is no need to use smp_read_barrier_depends() outside of the Alpha architecture code. Unfortunately, there is precisely _one_ user in the vhost code, and there isn't an obvious READ_ONCE() access making the barrier redundant. However, on closer inspection (thanks, Jason), it appears that vring synchronisation between the producer and consumer occurs via the 'avail_idx' field, which is followed up by an rmb() in vhost_get_vq_desc(), making the read_barrier_depends() redundant on Alpha. Jason says: | I'm also confused about the barrier here, basically in driver side | we did: | | 1) allocate pages | 2) store pages in indirect->addr | 3) smp_wmb() | 4) increase the avail idx (somehow a tail pointer of vring) | | in vhost we did: | | 1) read avail idx | 2) smp_rmb() | 3) read indirect->addr | 4) read from indirect->addr | | It looks to me even the data dependency barrier is not necessary | since we have rmb() which is sufficient for us to the correct | indirect->addr and driver are not expected to do any writing to | indirect->addr after avail idx is increased Remove the redundant barrier invocation. Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Suggested-by: Jason Wang <jasowang@redhat.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2020-06-111-6/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge some more updates from Andrew Morton: - various hotfixes and minor things - hch's use_mm/unuse_mm clearnups Subsystems affected by this patch series: mm/hugetlb, scripts, kcov, lib, nilfs, checkpatch, lib, mm/debug, ocfs2, lib, misc. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: kernel: set USER_DS in kthread_use_mm kernel: better document the use_mm/unuse_mm API contract kernel: move use_mm/unuse_mm to kthread.c kernel: move use_mm/unuse_mm to kthread.c stacktrace: cleanup inconsistent variable type lib: test get_count_order/long in test_bitops.c mm: add comments on pglist_data zones ocfs2: fix spelling mistake and grammar mm/debug_vm_pgtable: fix kernel crash by checking for THP support lib: fix bitmap_parse() on 64-bit big endian archs checkpatch: correct check for kernel parameters doc nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() lib/lz4/lz4_decompress.c: document deliberate use of `&' kcov: check kcov_softirq in kcov_remote_stop() scripts/spelling: add a few more typos khugepaged: selftests: fix timeout condition in wait_for_scan()
| * kernel: set USER_DS in kthread_use_mmChristoph Hellwig2020-06-101-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some architectures like arm64 and s390 require USER_DS to be set for kernel threads to access user address space, which is the whole purpose of kthread_use_mm, but other like x86 don't. That has lead to a huge mess where some callers are fixed up once they are tested on said architectures, while others linger around and yet other like io_uring try to do "clever" optimizations for what usually is just a trivial asignment to a member in the thread_struct for most architectures. Make kthread_use_mm set USER_DS, and kthread_unuse_mm restore to the previous value instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Felipe Balbi <balbi@kernel.org> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhi Wang <zhi.a.wang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20200404094101.672954-7-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kernel: better document the use_mm/unuse_mm API contractChristoph Hellwig2020-06-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch the function documentation to kerneldoc comments, and add WARN_ON_ONCE asserts that the calling thread is a kernel thread and does not have ->mm set (or has ->mm set in the case of unuse_mm). Also give the functions a kthread_ prefix to better document the use case. [hch@lst.de: fix a comment typo, cover the newly merged use_mm/unuse_mm caller in vfio] Link: http://lkml.kernel.org/r/20200416053158.586887-3-hch@lst.de [sfr@canb.auug.org.au: powerpc/vas: fix up for {un}use_mm() rename] Link: http://lkml.kernel.org/r/20200422163935.5aa93ba5@canb.auug.org.au Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [usb] Acked-by: Haren Myneni <haren@linux.ibm.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Felipe Balbi <balbi@kernel.org> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhi Wang <zhi.a.wang@intel.com> Link: http://lkml.kernel.org/r/20200404094101.672954-6-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kernel: move use_mm/unuse_mm to kthread.cChristoph Hellwig2020-06-101-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "improve use_mm / unuse_mm", v2. This series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API. This patch (of 3): Use the proper API instead. Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de These helpers are only for use with kernel threads, and I will tie them more into the kthread infrastructure going forward. Also move the prototypes to kthread.h - mmu_context.h was a little weird to start with as it otherwise contains very low-level MM bits. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Felipe Balbi <balbi@kernel.org> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhi Wang <zhi.a.wang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de Link: http://lkml.kernel.org/r/20200416053158.586887-1-hch@lst.de Link: http://lkml.kernel.org/r/20200404094101.672954-5-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds2020-06-101-30/+68
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull virtio updates from Michael Tsirkin: - virtio-mem: paravirtualized memory hotplug - support doorbell mapping for vdpa - config interrupt support in ifc - fixes all over the place * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (40 commits) vhost/test: fix up after API change virtio_mem: convert device block size into 64bit virtio-mem: drop unnecessary initialization ifcvf: implement config interrupt in IFCVF vhost: replace -1 with VHOST_FILE_UNBIND in ioctls vhost_vdpa: Support config interrupt in vdpa ifcvf: ignore continuous setting same status value virtio-mem: Don't rely on implicit compiler padding for requests virtio-mem: Try to unplug the complete online memory block first virtio-mem: Use -ETXTBSY as error code if the device is busy virtio-mem: Unplug subblocks right-to-left virtio-mem: Drop manual check for already present memory virtio-mem: Add parent resource for all added "System RAM" virtio-mem: Better retry handling virtio-mem: Offline and remove completely unplugged memory blocks mm/memory_hotplug: Introduce offline_and_remove_memory() virtio-mem: Allow to offline partially unplugged memory blocks mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE virtio-mem: Paravirtualized memory hotunplug part 2 virtio-mem: Paravirtualized memory hotunplug part 1 ...
| * vhost: replace -1 with VHOST_FILE_UNBIND in ioctlsZhu Lingshan2020-06-061-4/+4
| | | | | | | | | | | | | | | | | | | | This commit replaces -1 with VHOST_FILE_UNBIND in ioctls since we have added such a macro in the uapi header for vdpa_host. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/1591352835-22441-5-git-send-email-lingshan.zhu@intel.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: (cosmetic) remove a superfluous variable initialisationGuennadi Liakhovetski2020-06-041-1/+1
| | | | | | | | | | | | | | | | | | Even the compiler is able to figure out that in this case the initialisation is superfluous. Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com> Link: https://lore.kernel.org/r/20200527180541.5570-3-guennadi.liakhovetski@linux.intel.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: use mmgrab() instead of mmget() for non worker deviceJason Wang2020-06-041-8/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the device that doesn't use vhost worker and use_mm(), mmget() is too heavy weight and it may brings troubles for implementing mmap() support for vDPA device. This is because, an reference to the address space was held via mm_get() in vhost_dev_set_owner() and an reference to the file was held in mmap(). This means when process exits, the mm can not be released thus we can not release the file. This patch tries to use mmgrab() instead of mmget(), which allows the address space to be destroy in process exit without releasing the mm structure itself. This is sufficient for vDPA device which pin user pages and does not depend on the address space to work. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200529080303.15449-3-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: allow device that does not depend on vhost workerJason Wang2020-06-041-13/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vDPA device currently relays the eventfd via vhost worker. This is inefficient due the latency of wakeup and scheduling, so this patch tries to introduce a use_worker attribute for the vhost device. When use_worker is not set with vhost_dev_init(), vhost won't try to allocate a worker thread and the vhost_poll will be processed directly in the wakeup function. This help for vDPA since it reduces the latency caused by vhost worker. In my testing, it saves 0.2 ms in pings between VMs on a mutual host. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200529080303.15449-2-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * virtio: force spec specified alignment on typesMichael S. Tsirkin2020-06-021-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring element addresses are passed between components with different alignments assumptions. Thus, if guest/userspace selects a pointer and host then gets and dereferences it, we might need to decrease the compiler-selected alignment to prevent compiler on the host from assuming pointer is aligned. This actually triggers on ARM with -mabi=apcs-gnu - which is a deprecated configuration, but it seems safer to handle this generally. Note that userspace that allocates the memory is actually OK and does not need to be fixed, but userspace that gets it from guest or another process does need to be fixed. The later doesn't generally talk to the kernel so while it might be buggy it's not talking to the kernel in the buggy way - it's just using the header in the buggy way - so fixing header and asking userspace to recompile is the best we can do. I verified that the produced kernel binary on x86 is exactly identical before and after the change. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
* | vhost: convert get_user_pages() --> pin_user_pages()John Hubbard2020-06-081-3/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code was using get_user_pages*(), in approximately a "Case 5" scenario (accessing the data within a page), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/20200529234309.484480-3-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vhost: missing __user tagsMichael S. Tsirkin2020-05-151-2/+2
| | | | | | | | | | | sparse warns about converting void * to void __user *. This is not new but only got noticed now that vhost is built on more systems. This is just a question of __user tags missing in a couple of places, so fix it up. Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: factor out IOTLBJason Wang2020-04-011-152/+69
| | | | | | | | | | | This patch factors out IOTLB into a dedicated module in order to be reused by other modules like vringh. User may choose to enable the automatic retiring by specifying VHOST_IOTLB_FLAG_RETIRE flag to fit for the case of vhost device IOTLB implementation. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-4-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: allow per device message handlerJason Wang2020-04-011-2/+10
| | | | | | | | | | This patch allow device to register its own message handler during vhost_dev_init(). vDPA device will use it to implement its own DMA mapping logic. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-3-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost, kcov: collect coverage from vhost_workerAndrey Konovalov2019-12-041-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add kcov_remote_start()/kcov_remote_stop() annotations to the vhost_worker() function, which is responsible for processing vhost works. Since vhost_worker() threads are spawned per vhost device instance the common kcov handle is used for kcov_remote_start()/stop() annotations (see Documentation/dev-tools/kcov.rst for details). As the result kcov can now be used to collect coverage from vhost worker threads. Link: http://lkml.kernel.org/r/e49d5d154e5da6c9ada521d2b7ce10a49ce9f98b.1572366574.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Potapenko <glider@google.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Windsor <dwindsor@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Marco Elver <elver@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "vhost: block speculation of translated descriptors"Michael S. Tsirkin2019-09-141-4/+2
| | | | | | | | | | This reverts commit a89db445fbd7f1f8457b03759aa7343fa530ef6b. I was hasty to include this patch, and it breaks the build on 32 bit. Defence in depth is good but let's do it properly. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: make sure log_num < in_numyongduan2019-09-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | The code assumes log_num < in_num everywhere, and that is true as long as in_num is incremented by descriptor iov count, and log_num by 1. However this breaks if there's a zero sized descriptor. As a result, if a malicious guest creates a vring desc with desc.len = 0, it may cause the host kernel to crash by overflowing the log array. This bug can be triggered during the VM migration. There's no need to log when desc.len = 0, so just don't increment log_num in this case. Fixes: 3a4d5c94e959 ("vhost_net: a kernel-level virtio server") Cc: stable@vger.kernel.org Reviewed-by: Lidong Chen <lidongchen@tencent.com> Signed-off-by: ruippan <ruippan@tencent.com> Signed-off-by: yongduan <yongduan@tencent.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: block speculation of translated descriptorsMichael S. Tsirkin2019-09-111-2/+4
| | | | | | | | | | | | | | | | | | | iovec addresses coming from vhost are assumed to be pre-validated, but in fact can be speculated to a value out of range. Userspace address are later validated with array_index_nospec so we can be sure kernel info does not leak through these addresses, but vhost must also not leak userspace info outside the allowed memory table to guests. Following the defence in depth principle, make sure the address is not validated out of node range. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: stable@vger.kernel.org Acked-by: Jason Wang <jasowang@redhat.com> Tested-by: Jason Wang <jasowang@redhat.com>
* Revert "vhost: access vq metadata through kernel virtual address"Michael S. Tsirkin2019-09-041-512/+3
| | | | | | | | | | This reverts commit 7f466032dc ("vhost: access vq metadata through kernel virtual address"). The commit caused a bunch of issues, and while commit 73f628ec9e ("vhost: disable metadata prefetch optimization") disabled the optimization it's not nice to keep lots of dead code around. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* vhost: Remove unnecessary variableYunsheng Lin2019-09-041-3/+2
| | | | | | | | It is unnecessary to use ret variable to return the error code, just return the error code directly. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.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 Torvalds2019-07-171-123/+727
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull virtio, vhost updates from Michael Tsirkin: "Fixes, features, performance: - new iommu device - vhost guest memory access using vmap (just meta-data for now) - minor fixes" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio-mmio: add error check for platform_get_irq scsi: virtio_scsi: Use struct_size() helper iommu/virtio: Add event queue iommu/virtio: Add probe request iommu: Add virtio-iommu driver PCI: OF: Initialize dev->fwnode appropriately of: Allow the iommu-map property to omit untranslated devices dt-bindings: virtio: Add virtio-pci-iommu node dt-bindings: virtio-mmio: Add IOMMU description vhost: fix clang build warning vhost: access vq metadata through kernel virtual address vhost: factor out setting vring addr and num vhost: introduce helpers to get the size of metadata area vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch() vhost: fine grain userspace memory accessors vhost: generalize adding used elem
| * vhost: access vq metadata through kernel virtual addressJason Wang2019-06-051-3/+512
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was noticed that the copy_to/from_user() friends that was used to access virtqueue metdata tends to be very expensive for dataplane implementation like vhost since it involves lots of software checks, speculation barriers, hardware feature toggling (e.g SMAP). The extra cost will be more obvious when transferring small packets since the time spent on metadata accessing become more significant. This patch tries to eliminate those overheads by accessing them through direct mapping of those pages. Invalidation callbacks is implemented for co-operation with general VM management (swap, KSM, THP or NUMA balancing). We will try to get the direct mapping of vq metadata before each round of packet processing if it doesn't exist. If we fail, we will simplely fallback to copy_to/from_user() friends. This invalidation and direct mapping access are synchronized through spinlock and RCU. All matedata accessing through direct map is protected by RCU, and the setup or invalidation are done under spinlock. This method might does not work for high mem page which requires temporary mapping so we just fallback to normal copy_to/from_user() and may not for arch that has virtual tagged cache since extra cache flushing is needed to eliminate the alias. This will result complex logic and bad performance. For those archs, this patch simply go for copy_to/from_user() friends. This is done by ruling out kernel mapping codes through ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE. Note that this is only done when device IOTLB is not enabled. We could use similar method to optimize IOTLB in the future. Tests shows at most about 23% improvement on TX PPS when using virtio-user + vhost_net + xdp1 + TAP on 2.6GHz Broadwell: SMAP on | SMAP off Before: 5.2Mpps | 7.1Mpps After: 6.4Mpps | 8.2Mpps Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Jerome Glisse <jglisse@redhat.com> Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-parisc@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: factor out setting vring addr and numJason Wang2019-06-051-74/+103
| | | | | | | | | | | | | | | | Factoring vring address and num setting which needs special care for accelerating vq metadata accessing. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: introduce helpers to get the size of metadata areaJason Wang2019-06-051-18/+33
| | | | | | | | | | | | | | To avoid code duplication since it will be used by kernel VA prefetching. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch()Jason Wang2019-06-051-2/+2
| | | | | | | | | | | | | | | | | | Rename the function to be more accurate since it actually tries to prefetch vq metadata address in IOTLB. And this will be used by following patch to prefetch metadata virtual addresses. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: fine grain userspace memory accessorsJason Wang2019-06-051-17/+77
| | | | | | | | | | | | | | | | This is used to hide the metadata address from virtqueue helpers. This will allow to implement a vmap based fast accessing to metadata. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| * vhost: generalize adding used elemJason Wang2019-06-051-10/+1
| | | | | | | | | | | | | | | | | | | | Use one generic vhost_copy_to_user() instead of two dedicated accessor. This will simplify the conversion to fine grain accessors. About 2% improvement of PPS were seen during vitio-user txonly test. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds2019-07-091-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
| * | Merge tag 'v5.2-rc4' into mauroJonathan Corbet2019-06-141-1/+19
| |\| | | | | | | | | | | | | We need to pick up post-rc1 changes to various document files so they don't get lost in Mauro's massive RST conversion push.
| * | docs: fix broken documentation linksMauro Carvalho Chehab2019-06-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482Thomas Gleixner2019-06-191-2/+1
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this work is licensed under the terms of the gnu gpl version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 48 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081204.624030236@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vhost: introduce vhost_exceeds_weight()Jason Wang2019-05-271-1/+19
|/ | | | | | | | | | | | | | | | We used to have vhost_exceeds_weight() for vhost-net to: - prevent vhost kthread from hogging the cpu - balance the time spent between TX and RX This function could be useful for vsock and scsi as well. So move it to vhost.c. Device must specify a weight which counts the number of requests, or it can also specific a byte_weight which counts the number of bytes that has been processed. Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny2019-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vhost: reject zero size iova rangeJason Wang2019-04-101-1/+5
| | | | | | | | | | | We used to accept zero size iova range which will lead a infinite loop in translate_desc(). Fixing this by failing the request in this case. Reported-by: syzbot+d21e6e297322a900c128@syzkaller.appspotmail.com Fixes: 6b1e6cc7 ("vhost: new device IOTLB API") 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>
* vhost: silence an unused-variable warningArnd Bergmann2019-03-061-1/+1
| | | | | | | | | | | | | | On some architectures, the MMU can be disabled, leading to access_ok() becoming an empty macro that does not evaluate its size argument, which in turn produces an unused-variable warning: drivers/vhost/vhost.c:1191:9: error: unused variable 's' [-Werror,-Wunused-variable] size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; Mark the variable as __maybe_unused to shut up that warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>