/* * This file and its contents are supplied under the terms of the * Common Development and Distribution License ("CDDL"), version 1.0. * You may only use this file in accordance with the terms of version * 1.0 of the CDDL. * * A full copy of the text of the CDDL should have accompanied this * source. A copy of the CDDL is also available via the Internet at * http://www.illumos.org/license/CDDL. */ /* * Copyright 2019 Joyent, Inc. * Copyright 2022 OmniOS Community Edition (OmniOSce) Association. * Copyright 2025 Oxide Computer Company */ #ifndef _VIRTIO_SPEC_H #define _VIRTIO_SPEC_H /* * VIRTIO FRAMEWORK: DEFINITIONS from the VirtIO specification * * For design and usage documentation, see the comments in "virtio.h". * * NOTE: Client drivers should not use definitions from this file. */ #include <sys/types.h> #include <sys/dditypes.h> #include <sys/list.h> #include <sys/ccompile.h> #ifdef __cplusplus extern "C" { #endif typedef struct virtio_vq_desc virtio_vq_desc_t; typedef struct virtio_vq_driver virtio_vq_driver_t; typedef struct virtio_vq_device virtio_vq_device_t; typedef struct virtio_vq_elem virtio_vq_elem_t; #define VIRTIO_MIN_MODERN_DEVID 0x1040 /* * PCI capability types as defined by the specification. */ typedef enum virtio_pci_cap_type { VPC_COMMON_CFG = 1, VPC_NOTIFY_CFG = 2, VPC_ISR_CFG = 3, VPC_DEVICE_CFG = 4, VPC_PCI_CFG = 5, } virtio_pci_cap_type_t; /* * PACKED STRUCTS FOR DEVICE ACCESS */ struct virtio_vq_desc { /* * Buffer physical address and length. */ uint64_t vqd_addr; uint32_t vqd_len; /* * Flags. Use with the VIRTQ_DESC_F_* family of constants. See below. */ uint16_t vqd_flags; /* * If VIRTQ_DESC_F_NEXT is set in flags, this refers to the next * descriptor in the chain by table index. */ uint16_t vqd_next; } __packed; /* * VIRTIO DESCRIPTOR FLAGS (vqd_flags) */ /* * NEXT: * Signals that this descriptor (direct or indirect) is part of a chain. * If populated, "vqd_next" names the next descriptor in the chain by its * table index. */ #define VIRTQ_DESC_F_NEXT (1 << 0) /* * WRITE: * Determines whether this buffer is to be written by the device (WRITE is * set) or by the driver (WRITE is not set). */ #define VIRTQ_DESC_F_WRITE (1 << 1) /* * INDIRECT: * This bit signals that a direct descriptor refers to an indirect * descriptor list, rather than directly to a buffer. This bit may only * be used in a direct descriptor; indirect descriptors are not allowed to * refer to additional layers of indirect tables. If this bit is set, * NEXT must be clear; indirect descriptors may not be chained. */ #define VIRTQ_DESC_F_INDIRECT (1 << 2) /* * This structure is variously known as the "available" or "avail" ring, or the * driver-owned portion of the queue structure. It is used by the driver to * submit descriptor chains to the device. */ struct virtio_vq_driver { uint16_t vqdr_flags; uint16_t vqdr_index; uint16_t vqdr_ring[]; } __packed; #define VIRTQ_AVAIL_F_NO_INTERRUPT (1 << 0) /* * We use the sizeof operator on this packed struct to calculate the offset of * subsequent structs. Ensure the compiler is not adding any padding to the * end of the struct. */ CTASSERT(sizeof (virtio_vq_driver_t) == offsetof(virtio_vq_driver_t, vqdr_ring)); struct virtio_vq_elem { /* * The device returns chains of descriptors by specifying the table * index of the first descriptor in the chain. */ uint32_t vqe_start; uint32_t vqe_len; } __packed; /* * This structure is variously known as the "used" ring, or the device-owned * portion of the queue structure. It is used by the device to return * completed descriptor chains to the driver. */ struct virtio_vq_device { uint16_t vqde_flags; uint16_t vqde_index; virtio_vq_elem_t vqde_ring[]; } __packed; #define VIRTQ_USED_F_NO_NOTIFY (1 << 0) /* * BASIC CONFIGURATION * * Legacy devices expose both their generic and their device-specific * configuration through PCI BAR0. */ #define VIRTIO_LEGACY_BAR 0 /* * These are offsets into the base configuration space available through the * virtio_lget*() and virtio_lput*() family of functions. These offsets are for * what the specification describes as the "legacy" mode of device operation. */ #define VIRTIO_LEGACY_FEATURES_DEVICE 0x00 /* 32 R */ #define VIRTIO_LEGACY_FEATURES_DRIVER 0x04 /* 32 R/W */ #define VIRTIO_LEGACY_QUEUE_ADDRESS 0x08 /* 32 R/W */ #define VIRTIO_LEGACY_QUEUE_SIZE 0x0C /* 16 R */ #define VIRTIO_LEGACY_QUEUE_SELECT 0x0E /* 16 R/W */ #define VIRTIO_LEGACY_QUEUE_NOTIFY 0x10 /* 16 R/W */ #define VIRTIO_LEGACY_DEVICE_STATUS 0x12 /* 8 R/W */ #define VIRTIO_LEGACY_ISR_STATUS 0x13 /* 8 R */ #define VIRTIO_LEGACY_MSIX_CONFIG 0x14 /* 16 R/W */ #define VIRTIO_LEGACY_MSIX_QUEUE 0x16 /* 16 R/W */ #define VIRTIO_LEGACY_CFG_OFFSET (VIRTIO_LEGACY_ISR_STATUS + 1) #define VIRTIO_LEGACY_CFG_OFFSET_MSIX (VIRTIO_LEGACY_MSIX_QUEUE + 2) #define VIRTIO_LEGACY_MSI_NO_VECTOR 0xFFFF /* * These are offsets into the common configuration space available through the * virtio_cmnget*() and virtio_cmnput*() family of functions. These offsets are * for what the specification describes as the "modern" mode of device * operation. */ #define VIRTIO_MODERN_COMMON_DFSELECT 0x00 /* 32 R/W */ #define VIRTIO_MODERN_COMMON_DF 0x04 /* 32 R */ #define VIRTIO_MODERN_COMMON_GFSELECT 0x08 /* 32 R/W */ #define VIRTIO_MODERN_COMMON_GF 0x0C /* 32 R/W */ #define VIRTIO_MODERN_COMMON_MSIX 0x10 /* 16 R/W */ #define VIRTIO_MODERN_COMMON_NUMQ 0x12 /* 16 R */ #define VIRTIO_MODERN_COMMON_STATUS 0x14 /* 8 R/W */ #define VIRTIO_MODERN_COMMON_CFGGENERATION 0x15 /* 8 R */ #define VIRTIO_MODERN_COMMON_Q_SELECT 0x16 /* 16 R/W */ #define VIRTIO_MODERN_COMMON_Q_SIZE 0x18 /* 16 R/W */ #define VIRTIO_MODERN_COMMON_Q_MSIX 0x1a /* 16 R/W */ #define VIRTIO_MODERN_COMMON_Q_ENABLE 0x1c /* 16 R/W */ #define VIRTIO_MODERN_COMMON_Q_NOFF 0x1e /* 16 R */ #define VIRTIO_MODERN_COMMON_Q_DESCLO 0x20 /* 32 R/W */ #define VIRTIO_MODERN_COMMON_Q_DESCHI 0x24 /* 32 R/W */ #define VIRTIO_MODERN_COMMON_Q_AVAILLO 0x28 /* 32 R/W */ #define VIRTIO_MODERN_COMMON_Q_AVAILHI 0x2c /* 32 R/W */ #define VIRTIO_MODERN_COMMON_Q_USEDLO 0x30 /* 32 R/W */ #define VIRTIO_MODERN_COMMON_Q_USEDHI 0x34 /* 32 R/W */ /* * Offsets into a VirtIO PCI capability: */ #define VIRTIO_PCI_CAP_LEN 2 /* 8 R */ #define VIRTIO_PCI_CAP_TYPE 3 /* 8 R */ #define VIRTIO_PCI_CAP_BAR 4 /* 8 R */ #define VIRTIO_PCI_CAP_ID 5 /* 32 R */ #define VIRTIO_PCI_CAP_BAROFF 8 /* 32 R */ #define VIRTIO_PCI_CAP_BARLEN 12 /* 32 R */ #define VIRTIO_PCI_CAP_MULTIPLIER 16 /* 32 R ; NOTIFY CFG ONLY */ /* * Bits in the Device Status byte: */ #define VIRTIO_STATUS_RESET 0 #define VIRTIO_STATUS_ACKNOWLEDGE (1 << 0) #define VIRTIO_STATUS_DRIVER (1 << 1) #define VIRTIO_STATUS_DRIVER_OK (1 << 2) #define VIRTIO_STATUS_FEAT_OK (1 << 3) #define VIRTIO_STATUS_DEV_NEEDS_RESET (1 << 6) #define VIRTIO_STATUS_FAILED (1 << 7) /* * Bits in the Interrupt Service Routine Status byte: */ #define VIRTIO_ISR_CHECK_QUEUES (1 << 0) #define VIRTIO_ISR_CHECK_CONFIG (1 << 1) /* * Bits in the Features fields: */ #define VIRTIO_F_ANY_LAYOUT (1ULL << 27) /* Legacy only */ #define VIRTIO_F_RING_INDIRECT_DESC (1ULL << 28) #define VIRTIO_F_VERSION_1 (1ULL << 32) /* * For devices operating in the legacy mode, virtqueues must be aligned on a * "page size" of 4096 bytes; this is also called the "Queue Align" value in * newer versions of the specification. */ #define VIRTIO_PAGE_SHIFT 12 #define VIRTIO_PAGE_SIZE (1 << VIRTIO_PAGE_SHIFT) CTASSERT(VIRTIO_PAGE_SIZE == 4096); CTASSERT(ISP2(VIRTIO_PAGE_SIZE)); /* * For devices operating via the modern interface, the virtqueue layout is more * flexible with each component having different alignment requirements. */ #define MODERN_VQ_ALIGN_DESC 16 #define MODERN_VQ_ALIGN_DRIVER 2 #define MODERN_VQ_ALIGN_DEVICE 4 #ifdef __cplusplus } #endif #endif /* _VIRTIO_SPEC_H */
