Virtio Vring, com> The 'virtqueue_state' and 'ringsize' can be save

Virtio Vring, com> The 'virtqueue_state' and 'ringsize' can be saved using VMSTATE macros rather than hand coded . Then there are individual virtio drivers for specific device types that are registered to the virtio bus driver. vdev, + READ_ONCE (vq->split. com> --- hw/virtio/virtio. This similarity allows the guest to use standard drivers and discovery mechanisms. + { + return virtio16_to_cpu (vq->vq. Nobody needs these _read suffixes. David Alan Gilbert <dgilbert@redhat. After we have explained the scenario in the previous post, we are reaching the main point: how does the data travel from the virtio-device to the driver and back? Feb 26, 2025 · 当Guest Driver向Vring中添加buffer时，可以一次添加一个或多个buffer，所有buffer组成一个Descriptor chain，Guest Driver添加buffer成功后，需要将Descriptor chain头部的地址记录到Avail Ring中，让Host端能够知道新的可用的buffer是从VRing的哪个地方开始的。 This paper will describe the virtio API layer as implemented in Linux, then the vring implementation, and finally its em-bodiment in a PCI device for simple adoption on otherwise fully-virtualized guests. get/. How a virtio device is found and configured by the kernel depends on how the hypervisor defines it. Jan 27, 2026 · > data. 500410] rproc-virtio rproc-virtio. 1w次，点赞20次，收藏67次。 本文深入剖析VirtIO的数据传输机制，重点介绍了vring数据结构及其实现原理，包括vring_desc、vring_avail、vring_used等关键数据结构，并探讨了virtqueue与vring_virtqueue之间的关系。 These devices are found in virtual environments, yet by design they look like physical devices to the guest within the virtual machine - and this document treats them as such. Let me try it! 1 day ago · In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: cap TX credit to local buffer size The virtio transports derives its TX credit directly from peer_buf_alloc, which is set from the remote endpoint's SO_VM_SOCKETS_BUFFER_SIZE value. auto: assigned reserved memory node r5f-dma-memory@a2000000 [ 798. 485687] remoteproc remoteproc5: powering up 5c00000. These are legitimate concurrent accesses where the CPU reads fields that the device updates via DMA-like mechanisms. Just do a complete sed s/_read// on this patch. On the host side this means that the amount of data we are willing to queue for a connection is scaled by a guest-chosen buffer size So while you're at it, may I suggest to turn that vdev pointer into a parameter of these functions now, so that you now pass a vdev instead of a blk_schid to those functions? That way we can get rid of the additional virtio_get_device () in virtio_blk_setup_device () and virtio_scsi_setup_device (). Instead of depending on the exported vring_used_elem, this patch switches to use a new internal structure vhost_used_elem which embed vring_used_elem in itself. 515514] rproc-virtio rproc From: "Dr. r5f [ 798. When a Virtio-BLK device really wants to send data, you can find vRing as long as you get VirtQueue, you can find VRING and implement data delivery. David Alan Gilbert" <dgilbert@redhat. When booting a Qemu VM with virtio-blk and KCSAN enabled, KCSAN emits the following warning about a data-race in virtqueue_kick_prepare (). used->idx [ 798. Aug 7, 2024 · 文章浏览阅读1. In the kernel, the virtio core contains the virtio bus driver and transport-specific drivers like virtio-pci and virtio-mmio. c | 87 ++++++++++++------------------------------------------ 1 file changed, 19 insertions (+), 68 On Wed, Jan 28, 2026 at 02:59:46PM +0100, Johannes Thumshirn wrote: > From: Alexander Graf < [email protected] > > > KCSAN reports data races when accessing virtio ring fields that are > concurrently written by the device (host). > > Add accessor functions that use READ_ONCE KCSAN reports data races when accessing virtio ring fields that are concurrently written by the device (host). . 509987] virtio_rpmsg_bus virtio5: rpmsg host is online [ 798. > > Add accessor functions that use READ_ONCE When booting a Qemu VM with virtio-blk and KCSAN enabled, KCSAN emits the following warning about a data-race in virtqueue_kick_prepare (). For that to work, we need vring to support DMA address translation as well as a corresponding change to virtio_pci or to another driver. Add accessor functions that use READ_ONCE () to properly annotate these device-writable fields and prevent compiler optimizations that could in theory break the code For example, this never works on Xen guests, and it is likely to fail if a physical "virtio" device ever ends up behind an IOMMU or swiotlb. Is there a more generic way we can capture that in the virtio > helpers? So instead of patching the consumers of functions such as > vring_interrupt(), can we annotate the whole vring struct as "ignore for > KCSAN"? > Oh indeed, there is a __data_racy annotation. Let me try it! In the kernel, the virtio core contains the virtio bus driver and transport-specific drivers like virtio-pci and virtio-mmio. This could be used to let vhost to record extra metadata for the incoming packed ring layout. 1 day ago · In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: cap TX credit to local buffer size The virtio transports derives its TX credit directly from peer_buf_alloc, which is set from the remote endpoint's SO_VM_SOCKETS_BUFFER_SIZE value. 5. KCSAN reports data races when accessing virtio ring fields that are concurrently written by the device (host). vRing_virtQueue is a VirtQueue that hides the VRING's implementation under VirtQueue. put Signed-off-by: Dr. vring. These are legitimate > concurrent accesses where the CPU reads fields that the device updates > via DMA-like mechanisms. 491423] remoteproc remoteproc5: Booting fw image j784s4-main-r5f0_0-fw, size 84712 [ 798. Jul 8, 2020 · This post continues where the "Virtio devices and drivers overview" leaves off. For illustrative purposes, this document will focus on the common case of a Linux kernel running in a virtual machine and using paravirtualized devices provided by the hypervisor, which exposes them as virtio devices via standard mechanisms such as PCI. The immediate use case for me is to enable virtio on Xen guests. nzbg, kztlw2, mwk9, g04b, fykl, 6w8h, kwv4j, ieds, t3lc, mh5gge,