mirror of
https://github.com/cloud-hypervisor/cloud-hypervisor.git
synced 2026-08-05 02:19:16 +00:00
0162d73ed8
This crate contains up to date definition of the Queue, AvailIter, DescriptorChain and Descriptor structures forked from the upstream crate rust-vmm/vm-virtio 27b18af01ee2d9564626e084a758a2b496d2c618. The following patches have been applied on top of this base in order to make it work correctly with Cloud Hypervisor requirements: - Add MSI vector field to the Queue In order to help with MSI/MSI-X support, it is convenient to store the value of the interrupt vector inside the Queue directly. - Handle address translations For devices with access to data in memory being translated, we add to the Queue the ability to translate the address stored in the descriptor. It is very helpful as it performs the translation right after the untranslated address is read from memory, avoiding any errors from happening from the consumer's crate perspective. It also allows the consumer to reduce greatly the amount of duplicated code for applying the translation in many different places. - Add helpers for Queue structure They are meant to help crate's consumers getting/setting information about the Queue. These patches can be found on the 'ch' branch from the Cloud Hypervisor fork: https://github.com/cloud-hypervisor/vm-virtio.git This patch takes care of updating the Cloud Hypervisor code in virtio-devices and vm-virtio to build correctly with the latest version of virtio-queue. Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
60 lines
2.2 KiB
Rust
60 lines
2.2 KiB
Rust
// Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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//
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// SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
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//! Virtio queue related constant definitions
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/// Marks a buffer as continuing via the next field.
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pub const VIRTQ_DESC_F_NEXT: u16 = 0x1;
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/// Marks a buffer as device write-only.
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pub const VIRTQ_DESC_F_WRITE: u16 = 0x2;
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/// Marks a buffer as containing a list of buffer descriptors.
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pub const VIRTQ_DESC_F_INDIRECT: u16 = 0x4;
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/// Flag to disable guest notification for used descriptors.
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pub const VIRTQ_USED_F_NO_NOTIFY: u16 = 0x1;
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/// Size of one element in the used ring, id (le32) + len (le32).
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pub(crate) const VIRTQ_USED_ELEMENT_SIZE: u64 = 8;
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/// Size of used ring header: flags (u16) + idx (u16)
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pub(crate) const VIRTQ_USED_RING_HEADER_SIZE: u64 = 4;
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/// Size of the used ring metadata: header + avail_event (le16).
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///
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/// The total size of the used ring is:
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/// VIRTQ_USED_RING_META_SIZE + VIRTQ_USED_ELEMENT_SIZE * queue_size.
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pub(crate) const VIRTQ_USED_RING_META_SIZE: u64 = VIRTQ_USED_RING_HEADER_SIZE + 2;
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/// Size of one element in the available ring (le16).
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pub(crate) const VIRTQ_AVAIL_ELEMENT_SIZE: u64 = 2;
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/// Size of available ring header: flags(u16) + idx(u16)
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pub(crate) const VIRTQ_AVAIL_RING_HEADER_SIZE: u64 = 4;
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/// Size of the available ring metadata: header + used_event (le16).
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///
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/// The total size of the available ring is:
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/// VIRTQ_AVAIL_RING_META_SIZE + VIRTQ_AVAIL_ELEMENT_SIZE * queue_size.
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pub(crate) const VIRTQ_AVAIL_RING_META_SIZE: u64 = VIRTQ_AVAIL_RING_HEADER_SIZE + 2;
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/// Size of virtio descriptor.
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///
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/// The Virtio Spec 1.0 defines the alignment of VirtIO descriptor is 16 bytes,
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/// which fulfills the explicit constraint of GuestMemory::read_obj().
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pub(crate) const VIRTQ_DESCRIPTOR_SIZE: usize = 16;
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/// Default guest physical address for descriptor table.
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pub(crate) const DEFAULT_DESC_TABLE_ADDR: u64 = 0x0;
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/// Default guest physical address for available ring.
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pub(crate) const DEFAULT_AVAIL_RING_ADDR: u64 = 0x0;
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/// Default guest physical address for used ring.
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pub(crate) const DEFAULT_USED_RING_ADDR: u64 = 0x0;
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/// Vector value used to disable MSI for a queue.
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pub const VIRTQ_MSI_NO_VECTOR: u16 = 0xffff;
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