drivers/network/dd/netkvm/virtio/virtio_pci.h

   1 /*
   2 * Virtio PCI driver
   3 *
   4 * This module allows virtio devices to be used over a virtual PCI device.
   5 * This can be used with QEMU based VMMs like KVM or Xen.
   6 *
   7 * Copyright IBM Corp. 2007
   8 *
   9 * Authors:
  10 *  Anthony Liguori  <aliguori@us.ibm.com>
  11 *
  12 * This header is BSD licensed so anyone can use the definitions to implement
  13 * compatible drivers/servers.
  14 *
  15 * Redistribution and use in source and binary forms, with or without
  16 * modification, are permitted provided that the following conditions
  17 * are met:
  18 * 1. Redistributions of source code must retain the above copyright
  19 *    notice, this list of conditions and the following disclaimer.
  20 * 2. Redistributions in binary form must reproduce the above copyright
  21 *    notice, this list of conditions and the following disclaimer in the
  22 *    documentation and/or other materials provided with the distribution.
  23 * 3. Neither the name of IBM nor the names of its contributors
  24 *    may be used to endorse or promote products derived from this software
  25 *    without specific prior written permission.
  26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
  27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29 * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
  30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36 * SUCH DAMAGE.
  37 */
  38
  39 #ifndef _LINUX_VIRTIO_PCI_H
  40 #define _LINUX_VIRTIO_PCI_H
  41
  42 #include "linux/types.h"
  43 #include "linux/virtio_config.h"
  44
  45 #ifndef VIRTIO_PCI_NO_LEGACY
  46
  47 /* A 32-bit r/o bitmask of the features supported by the host */
  48 #define VIRTIO_PCI_HOST_FEATURES    0
  49
  50 /* A 32-bit r/w bitmask of features activated by the guest */
  51 #define VIRTIO_PCI_GUEST_FEATURES   4
  52
  53 /* A 32-bit r/w PFN for the currently selected queue */
  54 #define VIRTIO_PCI_QUEUE_PFN        8
  55
  56 /* A 16-bit r/o queue size for the currently selected queue */
  57 #define VIRTIO_PCI_QUEUE_NUM        12
  58
  59 /* A 16-bit r/w queue selector */
  60 #define VIRTIO_PCI_QUEUE_SEL        14
  61
  62 /* A 16-bit r/w queue notifier */
  63 #define VIRTIO_PCI_QUEUE_NOTIFY     16
  64
  65 /* An 8-bit device status register.  */
  66 #define VIRTIO_PCI_STATUS           18
  67
  68 /* An 8-bit r/o interrupt status register.  Reading the value will return the
  69 * current contents of the ISR and will also clear it.  This is effectively
  70 * a read-and-acknowledge. */
  71 #define VIRTIO_PCI_ISR              19
  72
  73 /* MSI-X registers: only enabled if MSI-X is enabled. */
  74 /* A 16-bit vector for configuration changes. */
  75 #define VIRTIO_MSI_CONFIG_VECTOR    20
  76 /* A 16-bit vector for selected queue notifications. */
  77 #define VIRTIO_MSI_QUEUE_VECTOR     22
  78
  79 /* The remaining space is defined by each driver as the per-driver
  80 * configuration space */
  81 #define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
  82 /* Deprecated: please use VIRTIO_PCI_CONFIG_OFF instead */
  83 #define VIRTIO_PCI_CONFIG(msix_enabled) VIRTIO_PCI_CONFIG_OFF(msix_enabled)
  84
  85 /* How many bits to shift physical queue address written to QUEUE_PFN.
  86 * 12 is historical, and due to x86 page size. */
  87 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
  88
  89 /* The alignment to use between consumer and producer parts of vring.
  90 * x86 pagesize again. */
  91 #define VIRTIO_PCI_VRING_ALIGN      4096
  92
  93 #endif /* VIRTIO_PCI_NO_LEGACY */
  94
  95 /* The bit of the ISR which indicates a device configuration change. */
  96 #define VIRTIO_PCI_ISR_CONFIG       0x2
  97 /* Vector value used to disable MSI for queue */
  98 #define VIRTIO_MSI_NO_VECTOR        0xffff
  99
 100 /* IDs for different capabilities.  Must all exist. */
 101
 102 /* Common configuration */
 103 #define VIRTIO_PCI_CAP_COMMON_CFG   1
 104 /* Notifications */
 105 #define VIRTIO_PCI_CAP_NOTIFY_CFG   2
 106 /* ISR access */
 107 #define VIRTIO_PCI_CAP_ISR_CFG      3
 108 /* Device specific configuration */
 109 #define VIRTIO_PCI_CAP_DEVICE_CFG   4
 110 /* PCI configuration access */
 111 #define VIRTIO_PCI_CAP_PCI_CFG      5
 112
 113 /* This is the PCI capability header: */
 114 struct virtio_pci_cap {
 115     __u8 cap_vndr;      /* Generic PCI field: PCI_CAPABILITY_ID_VENDOR_SPECIFIC */
 116     __u8 cap_next;      /* Generic PCI field: next ptr. */
 117     __u8 cap_len;       /* Generic PCI field: capability length */
 118     __u8 cfg_type;      /* Identifies the structure. */
 119     __u8 bar;           /* Where to find it. */
 120     __u8 padding[3];    /* Pad to full dword. */
 121     __le32 offset;      /* Offset within bar. */
 122     __le32 length;      /* Length of the structure, in bytes. */
 123 };
 124
 125 struct virtio_pci_notify_cap {
 126     struct virtio_pci_cap cap;
 127     __le32 notify_off_multiplier;   /* Multiplier for queue_notify_off. */
 128 };
 129
 130 /* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
 131 struct virtio_pci_common_cfg {
 132     /* About the whole device. */
 133     __le32 device_feature_select;   /* read-write */
 134     __le32 device_feature;          /* read-only */
 135     __le32 guest_feature_select;    /* read-write */
 136     __le32 guest_feature;           /* read-write */
 137     __le16 msix_config;             /* read-write */
 138     __le16 num_queues;              /* read-only */
 139     __u8 device_status;             /* read-write */
 140     __u8 config_generation;         /* read-only */
 141
 142     /* About a specific virtqueue. */
 143     __le16 queue_select;            /* read-write */
 144     __le16 queue_size;              /* read-write, power of 2. */
 145     __le16 queue_msix_vector;       /* read-write */
 146     __le16 queue_enable;            /* read-write */
 147     __le16 queue_notify_off;        /* read-only */
 148     __le32 queue_desc_lo;           /* read-write */
 149     __le32 queue_desc_hi;           /* read-write */
 150     __le32 queue_avail_lo;          /* read-write */
 151     __le32 queue_avail_hi;          /* read-write */
 152     __le32 queue_used_lo;           /* read-write */
 153     __le32 queue_used_hi;           /* read-write */
 154 };
 155
 156 #define MAX_QUEUES_PER_DEVICE_DEFAULT 8
 157
 158 typedef struct virtio_queue_info
 159 {
 160     /* the actual virtqueue */
 161     struct virtqueue *vq;
 162     /* the number of entries in the queue */
 163     u16 num;
 164     /* the virtual address of the ring queue */
 165     void *queue;
 166 } VirtIOQueueInfo;
 167
 168 typedef struct virtio_system_ops {
 169     // device register access
 170     u8 (*vdev_read_byte)(ULONG_PTR ulRegister);
 171     u16 (*vdev_read_word)(ULONG_PTR ulRegister);
 172     u32 (*vdev_read_dword)(ULONG_PTR ulRegister);
 173     void (*vdev_write_byte)(ULONG_PTR ulRegister, u8 bValue);
 174     void (*vdev_write_word)(ULONG_PTR ulRegister, u16 wValue);
 175     void (*vdev_write_dword)(ULONG_PTR ulRegister, u32 ulValue);
 176
 177     // memory management
 178     void *(*mem_alloc_contiguous_pages)(void *context, size_t size);
 179     void (*mem_free_contiguous_pages)(void *context, void *virt);
 180     ULONGLONG (*mem_get_physical_address)(void *context, void *virt);
 181     void *(*mem_alloc_nonpaged_block)(void *context, size_t size);
 182     void (*mem_free_nonpaged_block)(void *context, void *addr);
 183
 184     // PCI config space access
 185     int (*pci_read_config_byte)(void *context, int where, u8 *bVal);
 186     int (*pci_read_config_word)(void *context, int where, u16 *wVal);
 187     int (*pci_read_config_dword)(void *context, int where, u32 *dwVal);
 188
 189     // PCI resource handling
 190     size_t (*pci_get_resource_len)(void *context, int bar);
 191     void *(*pci_map_address_range)(void *context, int bar, size_t offset, size_t maxlen);
 192
 193     // misc
 194     u16 (*vdev_get_msix_vector)(void *context, int queue);
 195     void (*vdev_sleep)(void *context, unsigned int msecs);
 196 } VirtIOSystemOps;
 197
 198 struct virtio_device;
 199 typedef struct virtio_device VirtIODevice;
 200
 201 struct virtio_device_ops
 202 {
 203     // read/write device config and read config generation counter
 204     void (*get_config)(VirtIODevice *vdev, unsigned offset, void *buf, unsigned len);
 205     void (*set_config)(VirtIODevice *vdev, unsigned offset, const void *buf, unsigned len);
 206     u32 (*get_config_generation)(VirtIODevice *vdev);
 207
 208     // read/write device status byte and reset the device
 209     u8 (*get_status)(VirtIODevice *vdev);
 210     void (*set_status)(VirtIODevice *vdev, u8 status);
 211     void (*reset)(VirtIODevice *vdev);
 212
 213     // get/set device feature bits
 214     u64 (*get_features)(VirtIODevice *vdev);
 215     NTSTATUS (*set_features)(VirtIODevice *vdev, u64 features);
 216
 217     // set config/queue MSI interrupt vector, returns the new vector
 218     u16 (*set_config_vector)(VirtIODevice *vdev, u16 vector);
 219     u16 (*set_queue_vector)(struct virtqueue *vq, u16 vector);
 220
 221     // query virtual queue size and memory requirements
 222     NTSTATUS (*query_queue_alloc)(VirtIODevice *vdev,
 223         unsigned index, unsigned short *pNumEntries,
 224         unsigned long *pRingSize,
 225         unsigned long *pHeapSize);
 226
 227     // allocate and initialize a queue
 228     NTSTATUS (*setup_queue)(struct virtqueue **queue,
 229         VirtIODevice *vdev, VirtIOQueueInfo *info,
 230         unsigned idx, u16 msix_vec);
 231
 232     // tear down and deallocate a queue
 233     void (*delete_queue)(VirtIOQueueInfo *info);
 234 };
 235
 236 struct virtio_device
 237 {
 238     // the I/O port BAR of the PCI device (legacy virtio devices only)
 239     ULONG_PTR addr;
 240
 241     // true if the device uses MSI interrupts
 242     bool msix_used;
 243
 244     // true if the VIRTIO_RING_F_EVENT_IDX feature flag has been negotiated
 245     bool event_suppression_enabled;
 246
 247     // true if the VIRTIO_F_RING_PACKED feature flag has been negotiated
 248     bool packed_ring;
 249
 250     // internal device operations, implemented separately for legacy and modern
 251     const struct virtio_device_ops *device;
 252
 253     // external callbacks implemented separately by different driver model drivers
 254     const struct virtio_system_ops *system;
 255
 256     // opaque context value passed as first argument to virtio_system_ops callbacks
 257     void *DeviceContext;
 258
 259     // the ISR status field, reading causes the device to de-assert an interrupt
 260     volatile u8 *isr;
 261
 262     // modern virtio device capabilities and related state
 263     volatile struct virtio_pci_common_cfg *common;
 264     volatile unsigned char *config;
 265     volatile unsigned char *notify_base;
 266     int notify_map_cap;
 267     u32 notify_offset_multiplier;
 268
 269     size_t config_len;
 270     size_t notify_len;
 271
 272     // maximum number of virtqueues that fit in the memory block pointed to by info
 273     ULONG maxQueues;
 274
 275     // points to inline_info if not more than MAX_QUEUES_PER_DEVICE_DEFAULT queues
 276     // are used, or to an external allocation otherwise
 277     VirtIOQueueInfo *info;
 278     VirtIOQueueInfo inline_info[MAX_QUEUES_PER_DEVICE_DEFAULT];
 279 };
 280
 281 /* Driver API: device init and shutdown
 282  * DeviceContext is a driver defined opaque value which will be passed to driver
 283  * supplied callbacks described in pSystemOps. pSystemOps must be non-NULL and all
 284  * its fields must be non-NULL. msix_used is true if and only if the device is
 285  * configured with MSI support.
 286  */
 287 NTSTATUS virtio_device_initialize(VirtIODevice *vdev,
 288                                   const VirtIOSystemOps *pSystemOps,
 289                                   void *DeviceContext,
 290                                   bool msix_used);
 291 void virtio_device_shutdown(VirtIODevice *vdev);
 292
 293 /* Driver API: device status manipulation
 294  * virtio_set_status should not be called by new drivers. Device status should only
 295  * be getting its bits set with virtio_add_status and reset all back to 0 with
 296  * virtio_device_reset. virtio_device_ready is a special version of virtio_add_status
 297  * which adds the VIRTIO_CONFIG_S_DRIVER_OK status bit.
 298  */
 299 u8 virtio_get_status(VirtIODevice *vdev);
 300 void virtio_set_status(VirtIODevice *vdev, u8 status);
 301 void virtio_add_status(VirtIODevice *vdev, u8 status);
 302
 303 void virtio_device_reset(VirtIODevice *vdev);
 304 void virtio_device_ready(VirtIODevice *vdev);
 305
 306 /* Driver API: device feature bitmap manipulation
 307  * Features passed to virtio_set_features should be a subset of features offered by
 308  * the device as returned from virtio_get_features. virtio_set_features sets the
 309  * VIRTIO_CONFIG_S_FEATURES_OK status bit if it is supported by the device.
 310  */
 311 #define virtio_is_feature_enabled(FeaturesList, Feature)  (!!((FeaturesList) & (1ULL << (Feature))))
 312 #define virtio_feature_enable(FeaturesList, Feature)      ((FeaturesList) |= (1ULL << (Feature)))
 313 #define virtio_feature_disable(FeaturesList, Feature)     ((FeaturesList) &= ~(1ULL << (Feature)))
 314
 315 u64 virtio_get_features(VirtIODevice *dev);
 316 NTSTATUS virtio_set_features(VirtIODevice *vdev, u64 features);
 317
 318 /* Driver API: device configuration access
 319  * Both virtio_get_config and virtio_set_config support arbitrary values of the len
 320  * parameter. Config items of length 1, 2, and 4 are read/written using one access,
 321  * length 8 is broken down to two 4 bytes accesses, and any other length is read or
 322  * written byte by byte.
 323  */
 324 void virtio_get_config(VirtIODevice *vdev, unsigned offset,
 325                        void *buf, unsigned len);
 326 void virtio_set_config(VirtIODevice *vdev, unsigned offset,
 327                        void *buf, unsigned len);
 328
 329 /* Driver API: virtqueue setup
 330  * virtio_reserve_queue_memory makes VirtioLib reserve memory for its virtqueue
 331  * bookkeeping. Drivers should call this function if they intend to set up queues
 332  * one by one with virtio_find_queue. virtio_find_queues (plural) internally takes
 333  * care of the reservation and virtio_reserve_queue_memory need not be called.
 334  * Note that in addition to queue interrupt vectors, virtio_find_queues also sets
 335  * up the device config vector as a convenience.
 336  * Drivers should treat the returned struct virtqueue pointers as opaque handles.
 337  */
 338 NTSTATUS virtio_query_queue_allocation(VirtIODevice *vdev, unsigned index,
 339                                        unsigned short *pNumEntries,
 340                                        unsigned long *pRingSize,
 341                                        unsigned long *pHeapSize);
 342
 343 NTSTATUS virtio_reserve_queue_memory(VirtIODevice *vdev, unsigned nvqs);
 344
 345 NTSTATUS virtio_find_queue(VirtIODevice *vdev, unsigned index,
 346                            struct virtqueue **vq);
 347 NTSTATUS virtio_find_queues(VirtIODevice *vdev, unsigned nvqs,
 348                             struct virtqueue *vqs[]);
 349
 350 /* Driver API: virtqueue shutdown
 351  * The device must be reset and re-initialized to re-setup queues after they have
 352  * been deleted.
 353  */
 354 void virtio_delete_queue(struct virtqueue *vq);
 355 void virtio_delete_queues(VirtIODevice *vdev);
 356
 357 /* Driver API: virtqueue query and manipulation
 358  * virtio_get_queue_descriptor_size
 359  * is useful in situations where the driver has to prepare for the memory allocation
 360  * performed by virtio_reserve_queue_memory beforehand.
 361  */
 362
 363 u32 virtio_get_queue_size(struct virtqueue *vq);
 364 unsigned long virtio_get_indirect_page_capacity();
 365
 366 static ULONG FORCEINLINE virtio_get_queue_descriptor_size()
 367 {
 368     return sizeof(VirtIOQueueInfo);
 369 }
 370
 371 /* Driver API: interrupt handling
 372  * virtio_set_config_vector and virtio_set_queue_vector set the MSI vector used for
 373  * device configuration interrupt and queue interrupt, respectively. The driver may
 374  * choose to either return the vector from the vdev_get_msix_vector callback (called
 375  * as part of queue setup) or call these functions later. Note that setting the vector
 376  * may fail which is indicated by the return value of VIRTIO_MSI_NO_VECTOR.
 377  * virtio_read_isr_status returns the value of the ISR status register, note that it
 378  * is not idempotent, calling the function makes the device de-assert the interrupt.
 379  */
 380 u16 virtio_set_config_vector(VirtIODevice *vdev, u16 vector);
 381 u16 virtio_set_queue_vector(struct virtqueue *vq, u16 vector);
 382
 383 u8 virtio_read_isr_status(VirtIODevice *vdev);
 384
 385 /* Driver API: miscellaneous helpers
 386  * virtio_get_bar_index returns the corresponding BAR index given its physical address.
 387  * This tends to be useful to all drivers since Windows doesn't provide reliable BAR
 388  * indices as part of resource enumeration. The function returns -1 on failure.
 389  */
 390 int virtio_get_bar_index(PPCI_COMMON_HEADER pPCIHeader, PHYSICAL_ADDRESS BasePA);
 391
 392 #endif