sys/dev/pci/virtio_pcireg.h

root/sys/dev/pci/virtio_pcireg.h
/*
 * Copyright (c) 2019 Stefan Fritsch <sf@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _DEV_PCI_VIRTIO_PCIREG_H_
#define _DEV_PCI_VIRTIO_PCIREG_H_

/* Virtio 0.9 config space */
#define VIRTIO_CONFIG_DEVICE_FEATURES           0 /* 32bit */
#define VIRTIO_CONFIG_GUEST_FEATURES            4 /* 32bit */
#define VIRTIO_CONFIG_QUEUE_ADDRESS             8 /* 32bit */
#define VIRTIO_CONFIG_QUEUE_SIZE                12 /* 16bit */
#define VIRTIO_CONFIG_QUEUE_SELECT              14 /* 16bit */
#define VIRTIO_CONFIG_QUEUE_NOTIFY              16 /* 16bit */
#define VIRTIO_CONFIG_DEVICE_STATUS             18 /* 8bit */
#define VIRTIO_CONFIG_ISR_STATUS                19 /* 8bit */
#define  VIRTIO_CONFIG_ISR_CONFIG_CHANGE        2
#define VIRTIO_CONFIG_DEVICE_CONFIG_NOMSI       20
/* Only if MSIX is enabled: */
#define VIRTIO_MSI_CONFIG_VECTOR                20 /* 16bit, optional */
#define VIRTIO_MSI_QUEUE_VECTOR                 22 /* 16bit, optional */
#define VIRTIO_CONFIG_DEVICE_CONFIG_MSI         24

#define VIRTIO_MSI_NO_VECTOR                    0xffff

/*
 * Virtio 1.0 specific
 */

struct virtio_pci_cap {
        uint8_t cap_vndr;       /* Generic PCI field: PCI_CAP_ID_VNDR */
        uint8_t cap_next;       /* Generic PCI field: next ptr. */
        uint8_t cap_len;        /* Generic PCI field: capability length */
        uint8_t cfg_type;       /* Identifies the structure. */
        uint8_t bar;            /* Where to find it. */
        uint8_t padding[3];     /* Pad to full dword. */
        uint32_t offset;        /* Offset within bar. */
        uint32_t length;        /* Length of the structure, in bytes. */
} __packed;

/* Common configuration */
#define VIRTIO_PCI_CAP_COMMON_CFG       1
/* Notifications */
#define VIRTIO_PCI_CAP_NOTIFY_CFG       2
/* ISR Status */
#define VIRTIO_PCI_CAP_ISR_CFG          3
/* Device specific configuration */
#define VIRTIO_PCI_CAP_DEVICE_CFG       4
/* PCI configuration access */
#define VIRTIO_PCI_CAP_PCI_CFG          5

struct virtio_pci_notify_cap {
        struct virtio_pci_cap cap;
        uint32_t notify_off_multiplier; /* Multiplier for queue_notify_off. */
} __packed;

struct virtio_pci_cfg_cap {
        struct virtio_pci_cap cap;
        uint8_t pci_cfg_data[4];        /* Data for BAR access. */
} __packed;

struct virtio_pci_common_cfg {
        /* About the whole device. */
        uint32_t device_feature_select; /* read-write */
        uint32_t device_feature;        /* read-only for driver */
        uint32_t driver_feature_select; /* read-write */
        uint32_t driver_feature;        /* read-write */
        uint16_t config_msix_vector;    /* read-write */
        uint16_t num_queues;            /* read-only for driver */
        uint8_t device_status;          /* read-write */
        uint8_t config_generation;      /* read-only for driver */

        /* About a specific virtqueue. */
        uint16_t queue_select;          /* read-write */
        uint16_t queue_size;            /* read-write, power of 2, or 0. */
        uint16_t queue_msix_vector;     /* read-write */
        uint16_t queue_enable;          /* read-write */
        uint16_t queue_notify_off;      /* read-only for driver */
        uint64_t queue_desc;            /* read-write */
        uint64_t queue_avail;           /* read-write */
        uint64_t queue_used;            /* read-write */
} __packed;

#endif /* _DEV_PCI_VIRTIO_PCIREG_H_ */
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