/*
* Virtio PCI driver
*
* This module allows virtio devices to be used over a virtual PCI device.
* This can be used with QEMU based VMMs like KVM or Xen.
*
* Copyright IBM Corp. 2007
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This header is BSD licensed so anyone can use the definitions to implement
* compatible drivers/servers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of IBM nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _LINUX_VIRTIO_PCI_H
#define _LINUX_VIRTIO_PCI_H
#include "linux/types.h"
#include "linux/virtio_config.h"
#ifndef VIRTIO_PCI_NO_LEGACY
/* A 32-bit r/o bitmask of the features supported by the host */
#define VIRTIO_PCI_HOST_FEATURES 0
/* A 32-bit r/w bitmask of features activated by the guest */
#define VIRTIO_PCI_GUEST_FEATURES 4
/* A 32-bit r/w PFN for the currently selected queue */
#define VIRTIO_PCI_QUEUE_PFN 8
/* A 16-bit r/o queue size for the currently selected queue */
#define VIRTIO_PCI_QUEUE_NUM 12
/* A 16-bit r/w queue selector */
#define VIRTIO_PCI_QUEUE_SEL 14
/* A 16-bit r/w queue notifier */
#define VIRTIO_PCI_QUEUE_NOTIFY 16
/* An 8-bit device status register. */
#define VIRTIO_PCI_STATUS 18
/* An 8-bit r/o interrupt status register. Reading the value will return the
* current contents of the ISR and will also clear it. This is effectively
* a read-and-acknowledge. */
#define VIRTIO_PCI_ISR 19
/* MSI-X registers: only enabled if MSI-X is enabled. */
/* A 16-bit vector for configuration changes. */
#define VIRTIO_MSI_CONFIG_VECTOR 20
/* A 16-bit vector for selected queue notifications. */
#define VIRTIO_MSI_QUEUE_VECTOR 22
/* The remaining space is defined by each driver as the per-driver
* configuration space */
#define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
/* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
#define VIRTIO_PCI_CONFIG(msix_enabled) VIRTIO_PCI_CONFIG_OFF(msix_enabled)
/* How many bits to shift physical queue address written to QUEUE_PFN.
* 12 is historical, and due to x86 page size. */
#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
/* The alignment to use between consumer and producer parts of vring.
* x86 pagesize again. */
#define VIRTIO_PCI_VRING_ALIGN 4096
#endif /* VIRTIO_PCI_NO_LEGACY */
/* The bit of the ISR which indicates a device configuration change. */
#define VIRTIO_PCI_ISR_CONFIG 0x2
/* Vector value used to disable MSI for queue */
#define VIRTIO_MSI_NO_VECTOR 0xffff
/* IDs for different capabilities. Must all exist. */
/* Common configuration */
#define VIRTIO_PCI_CAP_COMMON_CFG 1
/* Notifications */
#define VIRTIO_PCI_CAP_NOTIFY_CFG 2
/* ISR access */
#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
/* This is the PCI capability header: */
struct virtio_pci_cap {
__u8 cap_vndr; /* Generic PCI field: PCI_CAPABILITY_ID_VENDOR_SPECIFIC */
__u8 cap_next; /* Generic PCI field: next ptr. */
__u8 cap_len; /* Generic PCI field: capability length */
__u8 cfg_type; /* Identifies the structure. */
__u8 bar; /* Where to find it. */
__u8 padding[3]; /* Pad to full dword. */
__le32 offset; /* Offset within bar. */
__le32 length; /* Length of the structure, in bytes. */
};
struct virtio_pci_notify_cap {
struct virtio_pci_cap cap;
__le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
};
/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
struct virtio_pci_common_cfg {
/* About the whole device. */
__le32 device_feature_select; /* read-write */
__le32 device_feature; /* read-only */
__le32 guest_feature_select; /* read-write */
__le32 guest_feature; /* read-write */
__le16 msix_config; /* read-write */
__le16 num_queues; /* read-only */
__u8 device_status; /* read-write */
__u8 config_generation; /* read-only */
/* About a specific virtqueue. */
__le16 queue_select; /* read-write */
__le16 queue_size; /* read-write, power of 2. */
__le16 queue_msix_vector; /* read-write */
__le16 queue_enable; /* read-write */
__le16 queue_notify_off; /* read-only */
__le32 queue_desc_lo; /* read-write */
__le32 queue_desc_hi; /* read-write */
__le32 queue_avail_lo; /* read-write */
__le32 queue_avail_hi; /* read-write */
__le32 queue_used_lo; /* read-write */
__le32 queue_used_hi; /* read-write */
};
#define MAX_QUEUES_PER_DEVICE_DEFAULT 8
typedef struct virtio_queue_info
{
/* the actual virtqueue */
struct virtqueue *vq;
/* the number of entries in the queue */
u16 num;
/* the virtual address of the ring queue */
void *queue;
} VirtIOQueueInfo;
typedef struct virtio_system_ops {
// device register access
u8 (*vdev_read_byte)(ULONG_PTR ulRegister);
u16 (*vdev_read_word)(ULONG_PTR ulRegister);
u32 (*vdev_read_dword)(ULONG_PTR ulRegister);
void (*vdev_write_byte)(ULONG_PTR ulRegister, u8 bValue);
void (*vdev_write_word)(ULONG_PTR ulRegister, u16 wValue);
void (*vdev_write_dword)(ULONG_PTR ulRegister, u32 ulValue);
// memory management
void *(*mem_alloc_contiguous_pages)(void *context, size_t size);
void (*mem_free_contiguous_pages)(void *context, void *virt);
ULONGLONG (*mem_get_physical_address)(void *context, void *virt);
void *(*mem_alloc_nonpaged_block)(void *context, size_t size);
void (*mem_free_nonpaged_block)(void *context, void *addr);
// PCI config space access
int (*pci_read_config_byte)(void *context, int where, u8 *bVal);
int (*pci_read_config_word)(void *context, int where, u16 *wVal);
int (*pci_read_config_dword)(void *context, int where, u32 *dwVal);
// PCI resource handling
size_t (*pci_get_resource_len)(void *context, int bar);
void *(*pci_map_address_range)(void *context, int bar, size_t offset, size_t maxlen);
// misc
u16 (*vdev_get_msix_vector)(void *context, int queue);
void (*vdev_sleep)(void *context, unsigned int msecs);
} VirtIOSystemOps;
struct virtio_device;
typedef struct virtio_device VirtIODevice;
struct virtio_device_ops
{
// read/write device config and read config generation counter
void (*get_config)(VirtIODevice *vdev, unsigned offset, void *buf, unsigned len);
void (*set_config)(VirtIODevice *vdev, unsigned offset, const void *buf, unsigned len);
u32 (*get_config_generation)(VirtIODevice *vdev);
// read/write device status byte and reset the device
u8 (*get_status)(VirtIODevice *vdev);
void (*set_status)(VirtIODevice *vdev, u8 status);
void (*reset)(VirtIODevice *vdev);
// get/set device feature bits
u64 (*get_features)(VirtIODevice *vdev);
NTSTATUS (*set_features)(VirtIODevice *vdev, u64 features);
// set config/queue MSI interrupt vector, returns the new vector
u16 (*set_config_vector)(VirtIODevice *vdev, u16 vector);
u16 (*set_queue_vector)(struct virtqueue *vq, u16 vector);
// query virtual queue size and memory requirements
NTSTATUS (*query_queue_alloc)(VirtIODevice *vdev,
unsigned index, unsigned short *pNumEntries,
unsigned long *pRingSize,
unsigned long *pHeapSize);
// allocate and initialize a queue
NTSTATUS (*setup_queue)(struct virtqueue **queue,
VirtIODevice *vdev, VirtIOQueueInfo *info,
unsigned idx, u16 msix_vec);
// tear down and deallocate a queue
void (*delete_queue)(VirtIOQueueInfo *info);
};
struct virtio_device
{
// the I/O port BAR of the PCI device (legacy virtio devices only)
ULONG_PTR addr;
// true if the device uses MSI interrupts
bool msix_used;
// true if the VIRTIO_RING_F_EVENT_IDX feature flag has been negotiated
bool event_suppression_enabled;
// true if the VIRTIO_F_RING_PACKED feature flag has been negotiated
bool packed_ring;
// internal device operations, implemented separately for legacy and modern
const struct virtio_device_ops *device;
// external callbacks implemented separately by different driver model drivers
const struct virtio_system_ops *system;
// opaque context value passed as first argument to virtio_system_ops callbacks
void *DeviceContext;
// the ISR status field, reading causes the device to de-assert an interrupt
volatile u8 *isr;
// modern virtio device capabilities and related state
volatile struct virtio_pci_common_cfg *common;
volatile unsigned char *config;
volatile unsigned char *notify_base;
int notify_map_cap;
u32 notify_offset_multiplier;
size_t config_len;
size_t notify_len;
// maximum number of virtqueues that fit in the memory block pointed to by info
ULONG maxQueues;
// points to inline_info if not more than MAX_QUEUES_PER_DEVICE_DEFAULT queues
// are used, or to an external allocation otherwise
VirtIOQueueInfo *info;
VirtIOQueueInfo inline_info[MAX_QUEUES_PER_DEVICE_DEFAULT];
};
/* Driver API: device init and shutdown
* DeviceContext is a driver defined opaque value which will be passed to driver
* supplied callbacks described in pSystemOps. pSystemOps must be non-NULL and all
* its fields must be non-NULL. msix_used is true if and only if the device is
* configured with MSI support.
*/
NTSTATUS virtio_device_initialize(VirtIODevice *vdev,
const VirtIOSystemOps *pSystemOps,
void *DeviceContext,
bool msix_used);
void virtio_device_shutdown(VirtIODevice *vdev);
/* Driver API: device status manipulation
* virtio_set_status should not be called by new drivers. Device status should only
* be getting its bits set with virtio_add_status and reset all back to 0 with
* virtio_device_reset. virtio_device_ready is a special version of virtio_add_status
* which adds the VIRTIO_CONFIG_S_DRIVER_OK status bit.
*/
u8 virtio_get_status(VirtIODevice *vdev);
void virtio_set_status(VirtIODevice *vdev, u8 status);
void virtio_add_status(VirtIODevice *vdev, u8 status);
void virtio_device_reset(VirtIODevice *vdev);
void virtio_device_ready(VirtIODevice *vdev);
/* Driver API: device feature bitmap manipulation
* Features passed to virtio_set_features should be a subset of features offered by
* the device as returned from virtio_get_features. virtio_set_features sets the
* VIRTIO_CONFIG_S_FEATURES_OK status bit if it is supported by the device.
*/
#define virtio_is_feature_enabled(FeaturesList, Feature) (!!((FeaturesList) & (1ULL << (Feature))))
#define virtio_feature_enable(FeaturesList, Feature) ((FeaturesList) |= (1ULL << (Feature)))
#define virtio_feature_disable(FeaturesList, Feature) ((FeaturesList) &= ~(1ULL << (Feature)))
u64 virtio_get_features(VirtIODevice *dev);
NTSTATUS virtio_set_features(VirtIODevice *vdev, u64 features);
/* Driver API: device configuration access
* Both virtio_get_config and virtio_set_config support arbitrary values of the len
* parameter. Config items of length 1, 2, and 4 are read/written using one access,
* length 8 is broken down to two 4 bytes accesses, and any other length is read or
* written byte by byte.
*/
void virtio_get_config(VirtIODevice *vdev, unsigned offset,
void *buf, unsigned len);
void virtio_set_config(VirtIODevice *vdev, unsigned offset,
void *buf, unsigned len);
/* Driver API: virtqueue setup
* virtio_reserve_queue_memory makes VirtioLib reserve memory for its virtqueue
* bookkeeping. Drivers should call this function if they intend to set up queues
* one by one with virtio_find_queue. virtio_find_queues (plural) internally takes
* care of the reservation and virtio_reserve_queue_memory need not be called.
* Note that in addition to queue interrupt vectors, virtio_find_queues also sets
* up the device config vector as a convenience.
* Drivers should treat the returned struct virtqueue pointers as opaque handles.
*/
NTSTATUS virtio_query_queue_allocation(VirtIODevice *vdev, unsigned index,
unsigned short *pNumEntries,
unsigned long *pRingSize,
unsigned long *pHeapSize);
NTSTATUS virtio_reserve_queue_memory(VirtIODevice *vdev, unsigned nvqs);
NTSTATUS virtio_find_queue(VirtIODevice *vdev, unsigned index,
struct virtqueue **vq);
NTSTATUS virtio_find_queues(VirtIODevice *vdev, unsigned nvqs,
struct virtqueue *vqs[]);
/* Driver API: virtqueue shutdown
* The device must be reset and re-initialized to re-setup queues after they have
* been deleted.
*/
void virtio_delete_queue(struct virtqueue *vq);
void virtio_delete_queues(VirtIODevice *vdev);
/* Driver API: virtqueue query and manipulation
* virtio_get_queue_descriptor_size
* is useful in situations where the driver has to prepare for the memory allocation
* performed by virtio_reserve_queue_memory beforehand.
*/
u32 virtio_get_queue_size(struct virtqueue *vq);
unsigned long virtio_get_indirect_page_capacity();
static ULONG FORCEINLINE virtio_get_queue_descriptor_size()
{
return sizeof(VirtIOQueueInfo);
}
/* Driver API: interrupt handling
* virtio_set_config_vector and virtio_set_queue_vector set the MSI vector used for
* device configuration interrupt and queue interrupt, respectively. The driver may
* choose to either return the vector from the vdev_get_msix_vector callback (called
* as part of queue setup) or call these functions later. Note that setting the vector
* may fail which is indicated by the return value of VIRTIO_MSI_NO_VECTOR.
* virtio_read_isr_status returns the value of the ISR status register, note that it
* is not idempotent, calling the function makes the device de-assert the interrupt.
*/
u16 virtio_set_config_vector(VirtIODevice *vdev, u16 vector);
u16 virtio_set_queue_vector(struct virtqueue *vq, u16 vector);
u8 virtio_read_isr_status(VirtIODevice *vdev);
/* Driver API: miscellaneous helpers
* virtio_get_bar_index returns the corresponding BAR index given its physical address.
* This tends to be useful to all drivers since Windows doesn't provide reliable BAR
* indices as part of resource enumeration. The function returns -1 on failure.
*/
int virtio_get_bar_index(PPCI_COMMON_HEADER pPCIHeader, PHYSICAL_ADDRESS BasePA);
#endif