e6a02746e0
This provides backdoor access to the device MMIOs, and every device should have one. From the virtio 1.0 spec (CS03): 4.1.4.7.1 Device Requirements: PCI configuration access capability The device MUST present at least one VIRTIO_PCI_CAP_PCI_CFG capability. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Michael S. Tsirkin <mst@redhat.com>
193 lines
6.8 KiB
C
193 lines
6.8 KiB
C
/*
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* Virtio PCI driver
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*
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* This module allows virtio devices to be used over a virtual PCI device.
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* This can be used with QEMU based VMMs like KVM or Xen.
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*
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* Copyright IBM Corp. 2007
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This header is BSD licensed so anyone can use the definitions to implement
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* compatible drivers/servers.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of IBM nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef _LINUX_VIRTIO_PCI_H
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#define _LINUX_VIRTIO_PCI_H
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#include <linux/types.h>
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#ifndef VIRTIO_PCI_NO_LEGACY
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/* A 32-bit r/o bitmask of the features supported by the host */
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#define VIRTIO_PCI_HOST_FEATURES 0
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/* A 32-bit r/w bitmask of features activated by the guest */
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#define VIRTIO_PCI_GUEST_FEATURES 4
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/* A 32-bit r/w PFN for the currently selected queue */
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#define VIRTIO_PCI_QUEUE_PFN 8
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/* A 16-bit r/o queue size for the currently selected queue */
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#define VIRTIO_PCI_QUEUE_NUM 12
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/* A 16-bit r/w queue selector */
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#define VIRTIO_PCI_QUEUE_SEL 14
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/* A 16-bit r/w queue notifier */
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#define VIRTIO_PCI_QUEUE_NOTIFY 16
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/* An 8-bit device status register. */
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#define VIRTIO_PCI_STATUS 18
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/* An 8-bit r/o interrupt status register. Reading the value will return the
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* current contents of the ISR and will also clear it. This is effectively
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* a read-and-acknowledge. */
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#define VIRTIO_PCI_ISR 19
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/* MSI-X registers: only enabled if MSI-X is enabled. */
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/* A 16-bit vector for configuration changes. */
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#define VIRTIO_MSI_CONFIG_VECTOR 20
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/* A 16-bit vector for selected queue notifications. */
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#define VIRTIO_MSI_QUEUE_VECTOR 22
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/* The remaining space is defined by each driver as the per-driver
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* configuration space */
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#define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
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/* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
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#define VIRTIO_PCI_CONFIG(dev) VIRTIO_PCI_CONFIG_OFF((dev)->msix_enabled)
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/* Virtio ABI version, this must match exactly */
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#define VIRTIO_PCI_ABI_VERSION 0
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/* How many bits to shift physical queue address written to QUEUE_PFN.
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* 12 is historical, and due to x86 page size. */
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#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
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/* The alignment to use between consumer and producer parts of vring.
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* x86 pagesize again. */
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#define VIRTIO_PCI_VRING_ALIGN 4096
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#endif /* VIRTIO_PCI_NO_LEGACY */
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/* The bit of the ISR which indicates a device configuration change. */
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#define VIRTIO_PCI_ISR_CONFIG 0x2
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/* Vector value used to disable MSI for queue */
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#define VIRTIO_MSI_NO_VECTOR 0xffff
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#ifndef VIRTIO_PCI_NO_MODERN
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/* IDs for different capabilities. Must all exist. */
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/* Common configuration */
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#define VIRTIO_PCI_CAP_COMMON_CFG 1
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/* Notifications */
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#define VIRTIO_PCI_CAP_NOTIFY_CFG 2
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/* ISR access */
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#define VIRTIO_PCI_CAP_ISR_CFG 3
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/* Device specific configuration */
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#define VIRTIO_PCI_CAP_DEVICE_CFG 4
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/* PCI configuration access */
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#define VIRTIO_PCI_CAP_PCI_CFG 5
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/* This is the PCI capability header: */
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struct virtio_pci_cap {
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__u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */
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__u8 cap_next; /* Generic PCI field: next ptr. */
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__u8 cap_len; /* Generic PCI field: capability length */
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__u8 cfg_type; /* Identifies the structure. */
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__u8 bar; /* Where to find it. */
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__u8 padding[3]; /* Pad to full dword. */
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__le32 offset; /* Offset within bar. */
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__le32 length; /* Length of the structure, in bytes. */
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};
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struct virtio_pci_notify_cap {
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struct virtio_pci_cap cap;
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__le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
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};
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/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
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struct virtio_pci_common_cfg {
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/* About the whole device. */
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__le32 device_feature_select; /* read-write */
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__le32 device_feature; /* read-only */
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__le32 guest_feature_select; /* read-write */
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__le32 guest_feature; /* read-write */
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__le16 msix_config; /* read-write */
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__le16 num_queues; /* read-only */
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__u8 device_status; /* read-write */
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__u8 config_generation; /* read-only */
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/* About a specific virtqueue. */
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__le16 queue_select; /* read-write */
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__le16 queue_size; /* read-write, power of 2. */
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__le16 queue_msix_vector; /* read-write */
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__le16 queue_enable; /* read-write */
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__le16 queue_notify_off; /* read-only */
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__le32 queue_desc_lo; /* read-write */
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__le32 queue_desc_hi; /* read-write */
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__le32 queue_avail_lo; /* read-write */
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__le32 queue_avail_hi; /* read-write */
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__le32 queue_used_lo; /* read-write */
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__le32 queue_used_hi; /* read-write */
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};
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/* Macro versions of offsets for the Old Timers! */
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#define VIRTIO_PCI_CAP_VNDR 0
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#define VIRTIO_PCI_CAP_NEXT 1
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#define VIRTIO_PCI_CAP_LEN 2
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#define VIRTIO_PCI_CAP_CFG_TYPE 3
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#define VIRTIO_PCI_CAP_BAR 4
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#define VIRTIO_PCI_CAP_OFFSET 8
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#define VIRTIO_PCI_CAP_LENGTH 12
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#define VIRTIO_PCI_NOTIFY_CAP_MULT 16
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#define VIRTIO_PCI_COMMON_DFSELECT 0
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#define VIRTIO_PCI_COMMON_DF 4
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#define VIRTIO_PCI_COMMON_GFSELECT 8
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#define VIRTIO_PCI_COMMON_GF 12
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#define VIRTIO_PCI_COMMON_MSIX 16
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#define VIRTIO_PCI_COMMON_NUMQ 18
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#define VIRTIO_PCI_COMMON_STATUS 20
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#define VIRTIO_PCI_COMMON_CFGGENERATION 21
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#define VIRTIO_PCI_COMMON_Q_SELECT 22
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#define VIRTIO_PCI_COMMON_Q_SIZE 24
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#define VIRTIO_PCI_COMMON_Q_MSIX 26
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#define VIRTIO_PCI_COMMON_Q_ENABLE 28
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#define VIRTIO_PCI_COMMON_Q_NOFF 30
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#define VIRTIO_PCI_COMMON_Q_DESCLO 32
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#define VIRTIO_PCI_COMMON_Q_DESCHI 36
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#define VIRTIO_PCI_COMMON_Q_AVAILLO 40
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#define VIRTIO_PCI_COMMON_Q_AVAILHI 44
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#define VIRTIO_PCI_COMMON_Q_USEDLO 48
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#define VIRTIO_PCI_COMMON_Q_USEDHI 52
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#endif /* VIRTIO_PCI_NO_MODERN */
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#endif
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