lwn.git/drivers/virtio/virtio_ring.c, branch docs-5.3

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102

2019-05-24T15:39:00+00:00

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 Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091649.499889647@linutronix.de Signed-off-by: Greg Kroah-Hartman

virtio/virtio_ring: do some comment fixes

2019-05-12T17:11:35+00:00

There are lots of mismatches between comments and codes, this patch do these comment fixes. Signed-off-by: Jiang Biao Signed-off-by: Michael S. Tsirkin

virtio_ring: Fix potential mem leak in virtqueue_add_indirect_packed

2019-05-12T17:11:35+00:00

'desc' should be freed before leaving from err handing path. Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Signed-off-by: YueHaibing Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang stable@vger.kernel.org

virtio: Honour 'may_reduce_num' in vring_create_virtqueue

2019-04-08T21:05:52+00:00

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 Signed-off-by: Michael S. Tsirkin Reviewed-by: Halil Pasic Reviewed-by: Jens Freimann

virtio: Introduce virtio_max_dma_size()

2019-03-06T16:19:15+00:00

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 Reviewed-by: Christoph Hellwig Signed-off-by: Joerg Roedel Signed-off-by: Michael S. Tsirkin

virtio: drop internal struct from UAPI

2019-02-05T20:29:48+00:00

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 Signed-off-by: Michael S. Tsirkin

virtio: support VIRTIO_F_ORDER_PLATFORM

2019-01-24T15:15:42+00:00

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 Signed-off-by: Michael S. Tsirkin

virtio_ring: advertize packed ring layout

2018-11-27T06:17:40+00:00

Advertize the packed ring layout support. Signed-off-by: Tiwei Bie Signed-off-by: David S. Miller

virtio_ring: leverage event idx in packed ring

2018-11-27T06:17:39+00:00

Leverage the EVENT_IDX feature in packed ring to suppress events when it's available. Signed-off-by: Tiwei Bie Signed-off-by: David S. Miller

virtio_ring: introduce packed ring support

2018-11-27T06:17:39+00:00

Introduce the packed ring support. Packed ring can only be created by vring_create_virtqueue() and each chunk of packed ring will be allocated individually. Packed ring can not be created on preallocated memory by vring_new_virtqueue() or the likes currently. Signed-off-by: Tiwei Bie Signed-off-by: David S. Miller