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path: root/drivers/virtio/virtio_ring.c
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2022-06-27virtio_ring: make vring_create_virtqueue_split prettierDeming Wang1-1/+1
Add some spaces to vring_alloc_queue(make it look prettier). Signed-off-by: Deming Wang <wangdeming@inspur.com> Message-Id: <20220622192306.4371-1-wangdeming@inspur.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-06-24virtio: disable notification hardening by defaultJason Wang1-0/+12
We try to harden virtio device notifications in 8b4ec69d7e09 ("virtio: harden vring IRQ"). It works with the assumption that the driver or core can properly call virtio_device_ready() at the right place. Unfortunately, this seems to be not true and uncover various bugs of the existing drivers, mainly the issue of using virtio_device_ready() incorrectly. So let's add a Kconfig option and disable it by default. It gives us time to fix the drivers and then we can consider re-enabling it. Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220622012940.21441-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2022-06-24virtio_ring : keep used_wrap_counter in vq->last_used_idxhuangjie.albert1-28/+47
the used_wrap_counter and the vq->last_used_idx may get out of sync if they are separate assignment,and interrupt might use an incorrect value to check for the used index. for example:OOB access ksoftirqd may consume the packet and it will call: virtnet_poll -->virtnet_receive -->virtqueue_get_buf_ctx -->virtqueue_get_buf_ctx_packed and in virtqueue_get_buf_ctx_packed: vq->last_used_idx += vq->packed.desc_state[id].num; if (unlikely(vq->last_used_idx >= vq->packed.vring.num)) { vq->last_used_idx -= vq->packed.vring.num; vq->packed.used_wrap_counter ^= 1; } if at the same time, there comes a vring interrupt,in vring_interrupt: we will call: vring_interrupt -->more_used -->more_used_packed -->is_used_desc_packed in is_used_desc_packed, the last_used_idx maybe >= vq->packed.vring.num. so this could case a memory out of bounds bug. this patch is to keep the used_wrap_counter in vq->last_used_idx so we can get the correct value to check for used index in interrupt. v3->v4: - use READ_ONCE/WRITE_ONCE to get/set vq->last_used_idx v2->v3: - add inline function to get used_wrap_counter and last_used - when use vq->last_used_idx, only read once if vq->last_used_idx is read twice, the values can be inconsistent. - use last_used_idx & ~(-(1 << VRING_PACKED_EVENT_F_WRAP_CTR)) to get the all bits below VRING_PACKED_EVENT_F_WRAP_CTR v1->v2: - reuse the VRING_PACKED_EVENT_F_WRAP_CTR - Remove parameter judgment in is_used_desc_packed, because it can't be illegal Signed-off-by: huangjie.albert <huangjie.albert@bytedance.com> Message-Id: <20220617020411.80367-1-huangjie.albert@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-31virtio: harden vring IRQJason Wang1-4/+7
This is a rework on the previous IRQ hardening that is done for virtio-pci where several drawbacks were found and were reverted: 1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ that is used by some device such as virtio-blk 2) done only for PCI transport The vq->broken is re-used in this patch for implementing the IRQ hardening. The vq->broken is set to true during both initialization and reset. And the vq->broken is set to false in virtio_device_ready(). Then vring_interrupt() can check and return when vq->broken is true. And in this case, switch to return IRQ_NONE to let the interrupt core aware of such invalid interrupt to prevent IRQ storm. The reason of using a per queue variable instead of a per device one is that we may need it for per queue reset hardening in the future. Note that the hardening is only done for vring interrupt since the config interrupt hardening is already done in commit 22b7050a024d7 ("virtio: defer config changed notifications"). But the method that is used by config interrupt can't be reused by the vring interrupt handler because it uses spinlock to do the synchronization which is expensive. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Vineeth Vijayan <vneethv@linux.ibm.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220527060120.20964-9-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2022-05-31virtio: allow to unbreak virtqueueJason Wang1-0/+22
This patch allows the new introduced __virtio_break_device() to unbreak the virtqueue. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Vineeth Vijayan <vneethv@linux.ibm.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220527060120.20964-8-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2022-05-31virtio: Replace unsigned with unsigned intSolomon Tan1-6/+6
This patch addresses the checkpatch.pl warning where unsigned int is preferred over unsigned. Signed-off-by: Solomon Tan <solomonbstoner@protonmail.ch> Message-Id: <YlzS49Wo8JMDhKOt@ArchDesktop> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-31virtio_ring: add unlikely annotation for free descs checkXianting Tian1-1/+1
The 'if (vq->vq.num_free < descs_used)' check will almost always be false. Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Message-Id: <20220328105817.1028065-2-xianting.tian@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2022-05-31virtio_ring: remove unnecessary to_vvq call in vring hot pathXianting Tian1-5/+3
It passes '_vq' to virtqueue_use_indirect(), which still calls to_vvq to get 'vq', let's directly pass 'vq'. It can avoid unnecessary call of to_vvq in hot path. Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Message-Id: <20220328105817.1028065-1-xianting.tian@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2022-03-28virtio_ring: remove flags check for unmap packed indirect descXuan Zhuo1-13/+5
When calling vring_unmap_desc_packed(), it will not encounter the situation that the flags contains VRING_DESC_F_INDIRECT. So remove this logic. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://lore.kernel.org/r/20220224110402.108161-4-xuanzhuo@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-28virtio_ring: remove flags check for unmap split indirect descXuan Zhuo1-13/+5
When calling vring_unmap_one_split_indirect(), it will not encounter the situation that the flags contains VRING_DESC_F_INDIRECT. So remove this logic. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://lore.kernel.org/r/20220224110402.108161-3-xuanzhuo@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-28virtio_ring: rename vring_unmap_state_packed() to vring_unmap_extra_packed()Xuan Zhuo1-9/+8
The actual parameter handled by vring_unmap_state_packed() is that vring_desc_extra, so this function should use "extra" instead of "state". Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://lore.kernel.org/r/20220224110402.108161-2-xuanzhuo@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-15virtio_ring: mark ring unused on errorMichael S. Tsirkin1-1/+3
A recently added error path does not mark ring unused when exiting on OOM, which will lead to BUG on the next entry in debug builds. TODO: refactor code so we have START_USE and END_USE in the same function. Fixes: fc6d70f40b3d ("virtio_ring: check desc == NULL when using indirect with packed") Cc: "Xuan Zhuo" <xuanzhuo@linux.alibaba.com> Cc: Jiasheng Jiang <jiasheng@iscas.ac.cn> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-12-08virtio_ring: Fix querying of maximum DMA mapping size for virtio deviceWill Deacon1-1/+1
virtio_max_dma_size() returns the maximum DMA mapping size of the virtio device by querying dma_max_mapping_size() for the device when the DMA API is in use for the vring. Unfortunately, the device passed is initialised by register_virtio_device() and does not inherit the DMA configuration from its parent, resulting in SWIOTLB errors when bouncing is enabled and the default 256K mapping limit (IO_TLB_SEGSIZE) is not respected: | virtio-pci 0000:00:01.0: swiotlb buffer is full (sz: 294912 bytes), total 1024 (slots), used 725 (slots) Follow the pattern used elsewhere in the virtio_ring code when calling into the DMA layer and pass the parent device to dma_max_mapping_size() instead. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20211201112018.25276-1-will@kernel.org Acked-by: Jason Wang <jasowang@redhat.com> Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Fixes: e6d6dd6c875e ("virtio: Introduce virtio_max_dma_size()") Cc: Joerg Roedel <jroedel@suse.de> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-25Revert "virtio_ring: validate used buffer length"Michael S. Tsirkin1-60/+0
This reverts commit 939779f5152d161b34f612af29e7dc1ac4472fcf. Attempts to validate length in the core did not work out: there turn out to exist multiple broken devices, and in particular legacy devices are known to be broken in this respect. We have ideas for handling this better in the next version but for now let's revert to a known good state to make sure drivers work for people. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01virtio_ring: validate used buffer lengthJason Wang1-0/+60
This patch validate the used buffer length provided by the device before trying to use it. This is done by record the in buffer length in a new field in desc_state structure during virtqueue_add(), then we can fail the virtqueue_get_buf() when we find the device is trying to give us a used buffer length which is greater than the in buffer length. Since some drivers have already done the validation by themselves, this patch tries to makes the core validation optional. For the driver that doesn't want the validation, it can set the suppress_used_validation to be true (which could be overridden by force_used_validation module parameter). To be more efficient, a dedicate array is used for storing the validate used length, this helps to eliminate the cache stress if validation is done by the driver. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20211027022107.14357-2-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01virtio_ring: fix typos in vring_desc_extraJason Wang1-2/+2
We're actually tracking descriptor address and length instead of the buffer. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20211019070152.8236-7-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01virtio_ring: check desc == NULL when using indirect with packedXuan Zhuo1-3/+11
When using indirect with packed, we don't check for allocation failures. This patch checks that and fall back on direct. Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://lore.kernel.org/r/20211020112323.67466-3-xuanzhuo@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01virtio_ring: make virtqueue_add_indirect_packed prettierXuan Zhuo1-6/+6
Align the arguments of virtqueue_add_indirect_packed() to the open ( to make it look prettier. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20211020112323.67466-2-xuanzhuo@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-10-27virtio-ring: fix DMA metadata flagsVincent Whitchurch1-1/+1
The flags are currently overwritten, leading to the wrong direction being passed to the DMA unmap functions. Fixes: 72b5e8958738aaa4 ("virtio-ring: store DMA metadata in desc_extra for split virtqueue") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Link: https://lore.kernel.org/r/20211026133100.17541-1-vincent.whitchurch@axis.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2021-08-11virtio_ring: pull in spinlock headerMichael S. Tsirkin1-0/+1
we use a spinlock now pull in the correct header to make virtio_ring.c self sufficient. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-08-10virtio: Protect vqs list accessParav Pandit1-0/+8
VQs may be accessed to mark the device broken while they are created/destroyed. Hence protect the access to the vqs list. Fixes: e2dcdfe95c0b ("virtio: virtio_break_device() to mark all virtqueues broken.") Signed-off-by: Parav Pandit <parav@nvidia.com> Link: https://lore.kernel.org/r/20210721142648.1525924-4-parav@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-08-10virtio: Keep vring_del_virtqueue() mirror of VQ createParav Pandit1-1/+2
Keep the vring_del_virtqueue() mirror of the create routines. i.e. to delete list entry first as it is added last during the create routine. Signed-off-by: Parav Pandit <parav@nvidia.com> Link: https://lore.kernel.org/r/20210721142648.1525924-3-parav@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-08-10virtio: Improve vq->broken access to avoid any compiler optimizationParav Pandit1-2/+4
Currently vq->broken field is read by virtqueue_is_broken() in busy loop in one context by virtnet_send_command(). vq->broken is set to true in other process context by virtio_break_device(). Reader and writer are accessing it without any synchronization. This may lead to a compiler optimization which may result to optimize reading vq->broken only once. Hence, force reading vq->broken on each invocation of virtqueue_is_broken() and also force writing it so that such update is visible to the readers. It is a theoretical fix that isn't yet encountered in the field. Signed-off-by: Parav Pandit <parav@nvidia.com> Link: https://lore.kernel.org/r/20210721142648.1525924-2-parav@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-ring: store DMA metadata in desc_extra for split virtqueueJason Wang1-25/+87
For split virtqueue, we used to depend on the address, length and flags stored in the descriptor ring for DMA unmapping. This is unsafe for the case since the device can manipulate the behavior of virtio driver, IOMMU drivers and swiotlb. For safety, maintain the DMA address, DMA length, descriptor flags and next filed of the non indirect descriptors in vring_desc_state_extra when DMA API is used for virtio as we did for packed virtqueue and use those metadata for performing DMA operations. Indirect descriptors should be safe since they are using streaming mappings. With this the descriptor ring is write only form the view of the driver. This slight increase the footprint of the drive but it's not noticed through pktgen (64B) test and netperf test in the case of virtio-net. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-8-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio: use err label in __vring_new_virtqueue()Jason Wang1-4/+6
Using error label for unwind in __vring_new_virtqueue. This is useful for future refacotring. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-7-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio_ring: introduce virtqueue_desc_add_split()Jason Wang1-15/+24
This patch introduces a helper for storing descriptor in the descriptor table for split virtqueue. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-6-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio_ring: secure handling of mapping errorsJason Wang1-1/+4
We should not depend on the DMA address, length and flag of descriptor table since they could be wrote with arbitrary value by the device. So this patch switches to use the stored one in desc_extra. Note that the indirect descriptors are fine since they are read-only streaming mappings. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-5-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-ring: factor out desc_extra allocationJason Wang1-10/+20
A helper is introduced for the logic of allocating the descriptor extra data. This will be reused by split virtqueue. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-4-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio_ring: rename vring_desc_extra_packedJason Wang1-5/+5
Rename vring_desc_extra_packed to vring_desc_extra since the structure are pretty generic which could be reused by split virtqueue as well. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-3-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-08virtio-ring: maintain next in extra state for packed virtqueueJason Wang1-7/+8
This patch moves next from vring_desc_state_packed to vring_desc_desc_extra_packed. This makes it simpler to let extra state to be reused by split virtqueue. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-2-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-03virtio: fix up virtio_disable_cbMichael S. Tsirkin1-1/+25
virtio_disable_cb is currently a nop for split ring with event index. This is because it used to be always called from a callback when we know device won't trigger more events until we update the index. However, now that we run with interrupts enabled a lot we also poll without a callback so that is different: disabling callbacks will help reduce the number of spurious interrupts. Further, if using event index with a packed ring, and if being called from a callback, we actually do disable interrupts which is unnecessary. Fix both issues by tracking whenever we get a callback. If that is the case disabling interrupts with event index can be a nop. If not the case disable interrupts. Note: with a split ring there's no explicit "no interrupts" value. For now we write a fixed value so our chance of triggering an interupt is 1/ring size. It's probably better to write something related to the last used index there to reduce the chance even further. For now I'm keeping it simple. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-03virtio_ring: Fix kernel-docYang Li1-1/+1
Fix function name in virtio_ring.c kernel-doc comment to remove a warning found by clang_w1. drivers/virtio/virtio_ring.c:1903: warning: expecting prototype for virtqueue_get_buf(). Prototype was for virtqueue_get_buf_ctx() instead Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Link: https://lore.kernel.org/r/1621998731-17445-1-git-send-email-yang.lee@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-19virtio_ring: Fix two use after free bugsDan Carpenter1-2/+2
The "vq" struct is added to the "vdev->vqs" list prematurely. If we encounter an error later in the function then the "vq" is freed, but since it is still on the list that could lead to a use after free bug. Fixes: cbeedb72b97a ("virtio_ring: allocate desc state for split ring separately") Reported-by: Robert Buhren <robert.buhren@sect.tu-berlin.de> Reported-by: Felicitas Hetzelt <file@sect.tu-berlin.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/X8pGaG/zkI3jk8mk@mwanda Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-12-19virtio_ring: Cut and paste bugs in vring_create_virtqueue_packed()Dan Carpenter1-2/+2
There is a copy and paste bug in the error handling of this code and it uses "ring_dma_addr" three times instead of "device_event_dma_addr" and "driver_event_dma_addr". Fixes: 1ce9e6055fa0 (" virtio_ring: introduce packed ring support") Reported-by: Robert Buhren <robert.buhren@sect.tu-berlin.de> Reported-by: Felicitas Hetzelt <file@sect.tu-berlin.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/X8pGRJlEzyn+04u2@mwanda Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-08-12Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-2/+5
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 ...
2020-08-05virtio_ring: Avoid loop when vq is broken in virtqueue_pollMao Wenan1-0/+3
The loop may exist if vq->broken is true, virtqueue_get_buf_ctx_packed or virtqueue_get_buf_ctx_split will return NULL, so virtnet_poll will reschedule napi to receive packet, it will lead cpu usage(si) to 100%. call trace as below: virtnet_poll virtnet_receive virtqueue_get_buf_ctx virtqueue_get_buf_ctx_packed virtqueue_get_buf_ctx_split virtqueue_napi_complete virtqueue_poll //return true virtqueue_napi_schedule //it will reschedule napi to fix this, return false if vq is broken in virtqueue_poll. Signed-off-by: Mao Wenan <wenan.mao@linux.alibaba.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/1596354249-96204-1-git-send-email-wenan.mao@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-08-03virtio: virtio_has_iommu_quirk -> virtio_has_dma_quirkMichael S. Tsirkin1-1/+1
Now that the corresponding feature bit has been renamed, rename the quirk too - it's about special ways to do DMA, not necessarily about the IOMMU. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-03virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORMMichael S. Tsirkin1-1/+1
Rename the bit to match latest virtio spec. Add a compat macro to avoid breaking existing userspace. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-07-16treewide: Remove uninitialized_var() usageKees Cook1-3/+3
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-03-08virtio_ring: Fix mem leak with vring_new_virtqueue()Suman Anna1-2/+2
The functions vring_new_virtqueue() and __vring_new_virtqueue() are used with split rings, and any allocations within these functions are managed outside of the .we_own_ring flag. The commit cbeedb72b97a ("virtio_ring: allocate desc state for split ring separately") allocates the desc state within the __vring_new_virtqueue() but frees it only when the .we_own_ring flag is set. This leads to a memory leak when freeing such allocated virtqueues with the vring_del_virtqueue() function. Fix this by moving the desc_state free code outside the flag and only for split rings. Issue was discovered during testing with remoteproc and virtio_rpmsg. Fixes: cbeedb72b97a ("virtio_ring: allocate desc state for split ring separately") Signed-off-by: Suman Anna <s-anna@ti.com> Link: https://lore.kernel.org/r/20200224212643.30672-1-s-anna@ti.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2019-11-19virtio_ring: fix return code on DMA mapping failsHalil Pasic1-2/+2
Commit 780bc7903a32 ("virtio_ring: Support DMA APIs") makes virtqueue_add() return -EIO when we fail to map our I/O buffers. This is a very realistic scenario for guests with encrypted memory, as swiotlb may run out of space, depending on it's size and the I/O load. The virtio-blk driver interprets -EIO form virtqueue_add() as an IO error, despite the fact that swiotlb full is in absence of bugs a recoverable condition. Let us change the return code to -ENOMEM, and make the block layer recover form these failures when virtio-blk encounters the condition described above. Cc: stable@vger.kernel.org Fixes: 780bc7903a32 ("virtio_ring: Support DMA APIs") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-28virtio_ring: fix stalls for packed ringsMarvin Liu1-4/+3
When VIRTIO_F_RING_EVENT_IDX is negotiated, virtio devices can use virtqueue_enable_cb_delayed_packed to reduce the number of device interrupts. At the moment, this is the case for virtio-net when the napi_tx module parameter is set to false. In this case, the virtio driver selects an event offset and expects that the device will send a notification when rolling over the event offset in the ring. However, if this roll-over happens before the event suppression structure update, the notification won't be sent. To address this race condition the driver needs to check wether the device rolled over the offset after updating the event suppression structure. With VIRTIO_F_RING_PACKED, the virtio driver did this by reading the flags field of the descriptor at the specified offset. Unfortunately, checking at the event offset isn't reliable: if descriptors are chained (e.g. when INDIRECT is off) not all descriptors are overwritten by the device, so it's possible that the device skipped the specific descriptor driver is checking when writing out used descriptors. If this happens, the driver won't detect the race condition and will incorrectly expect the device to send a notification. For virtio-net, the result will be a TX queue stall, with the transmission getting blocked forever. With the packed ring, it isn't easy to find a location which is guaranteed to change upon the roll-over, except the next device descriptor, as described in the spec: Writes of device and driver descriptors can generally be reordered, but each side (driver and device) are only required to poll (or test) a single location in memory: the next device descriptor after the one they processed previously, in circular order. while this might be sub-optimal, let's do exactly this for now. Cc: stable@vger.kernel.org Cc: Jason Wang <jasowang@redhat.com> Fixes: f51f982682e2a ("virtio_ring: leverage event idx in packed ring") Signed-off-by: Marvin Liu <yong.liu@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-09-09virtio_ring: fix unmap of indirect descriptorsMatthias Lange1-2/+6
The function virtqueue_add_split() DMA-maps the scatterlist buffers. In case a mapping error occurs the already mapped buffers must be unmapped. This happens by jumping to the 'unmap_release' label. In case of indirect descriptors the release is wrong and may leak kernel memory. Because the implementation assumes that the head descriptor is already mapped it starts iterating over the descriptor list starting from the head descriptor. However for indirect descriptors the head descriptor is never mapped in case of an error. The fix is to initialize the start index with zero in case of indirect descriptors and use the 'desc' pointer directly for iterating over the descriptor chain. Signed-off-by: Matthias Lange <matthias.lange@kernkonzept.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 50 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091649.499889647@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-12virtio/virtio_ring: do some comment fixesJiang Biao1-13/+14
There are lots of mismatches between comments and codes, this patch do these comment fixes. Signed-off-by: Jiang Biao <benbjiang@tencent.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-05-12virtio_ring: Fix potential mem leak in virtqueue_add_indirect_packedYueHaibing1-0/+1
'desc' should be freed before leaving from err handing path. Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> stable@vger.kernel.org
2019-04-09virtio: Honour 'may_reduce_num' in vring_create_virtqueueCornelia Huck1-0/+2
vring_create_virtqueue() allows the caller to specify via the may_reduce_num parameter whether the vring code is allowed to allocate a smaller ring than specified. However, the split ring allocation code tries to allocate a smaller ring on allocation failure regardless of what the caller specified. This may cause trouble for e.g. virtio-pci in legacy mode, which does not support ring resizing. (The packed ring code does not resize in any case.) Let's fix this by bailing out immediately in the split ring code if the requested size cannot be allocated and may_reduce_num has not been specified. While at it, fix a typo in the usage instructions. Fixes: 2a2d1382fe9d ("virtio: Add improved queue allocation API") Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Jens Freimann <jfreimann@redhat.com>
2019-03-06virtio: Introduce virtio_max_dma_size()Joerg Roedel1-0/+11
This function returns the maximum segment size for a single dma transaction of a virtio device. The possible limit comes from the SWIOTLB implementation in the Linux kernel, that has an upper limit of (currently) 256kb of contiguous memory it can map. Other DMA-API implementations might also have limits. Use the new dma_max_mapping_size() function to determine the maximum mapping size when DMA-API is in use for virtio. Cc: stable@vger.kernel.org Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-02-05virtio: drop internal struct from UAPIMichael S. Tsirkin1-1/+6
There's no reason to expose struct vring_packed in UAPI - if we do we won't be able to change or drop it, and it's not part of any interface. Let's move it to virtio_ring.c Cc: Tiwei Bie <tiwei.bie@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-01-24virtio: support VIRTIO_F_ORDER_PLATFORMTiwei Bie1-0/+8
This patch introduces the support for VIRTIO_F_ORDER_PLATFORM. If this feature is negotiated, the driver must use the barriers suitable for hardware devices. Otherwise, the device and driver are assumed to be implemented in software, that is they can be assumed to run on identical CPUs in an SMP configuration. Thus a weaker form of memory barriers is sufficient to yield better performance. It is recommended that an add-in card based PCI device offers this feature for portability. The device will fail to operate further or will operate in a slower emulation mode if this feature is offered but not accepted. Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>