/* How many devices? Assume each one wants up to two dma arrays per device. */
#define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2)
-/*D:200
- * Lguest I/O
- *
- * The lguest I/O mechanism is the only way Guests can talk to devices. There
- * are two hypercalls involved: SEND_DMA for output and BIND_DMA for input. In
- * each case, "struct lguest_dma" describes the buffer: this contains 16
- * addr/len pairs, and if there are fewer buffer elements the len array is
- * terminated with a 0.
- *
- * I/O is organized by keys: BIND_DMA attaches buffers to a particular key, and
- * SEND_DMA transfers to buffers bound to particular key. By convention, keys
- * correspond to a physical address within the device's page. This means that
- * devices will never accidentally end up with the same keys, and allows the
- * Host use The Futex Trick (as we'll see later in our journey).
- *
- * SEND_DMA simply indicates a key to send to, and the physical address of the
- * "struct lguest_dma" to send. The Host will write the number of bytes
- * transferred into the "struct lguest_dma"'s used_len member.
- *
- * BIND_DMA indicates a key to bind to, a pointer to an array of "struct
- * lguest_dma"s ready for receiving, the size of that array, and an interrupt
- * to trigger when data is received. The Host will only allow transfers into
- * buffers with a used_len of zero: it then sets used_len to the number of
- * bytes transferred and triggers the interrupt for the Guest to process the
- * new input. */
-struct lguest_dma
-{
- /* 0 if free to be used, filled by the Host. */
- __u32 used_len;
- __u16 len[LGUEST_MAX_DMA_SECTIONS];
- unsigned long addr[LGUEST_MAX_DMA_SECTIONS];
-};
-/*:*/
-
-/*D:460 This is the layout of a block device memory page. The Launcher sets up
- * the num_sectors initially to tell the Guest the size of the disk. The Guest
- * puts the type, sector and length of the request in the first three fields,
- * then DMAs to the Host. The Host processes the request, sets up the result,
- * then DMAs back to the Guest. */
-struct lguest_block_page
-{
- /* 0 is a read, 1 is a write. */
- int type;
- __u32 sector; /* Offset in device = sector * 512. */
- __u32 bytes; /* Length expected to be read/written in bytes */
- /* 0 = pending, 1 = done, 2 = done, error */
- int result;
- __u32 num_sectors; /* Disk length = num_sectors * 512 */
-};
-
-/*D:520 The network device is basically a memory page where all the Guests on
- * the network publish their MAC (ethernet) addresses: it's an array of "struct
- * lguest_net": */
-struct lguest_net
-{
- /* Simply the mac address (with multicast bit meaning promisc). */
- unsigned char mac[6];
-};
-/*:*/
-
/* Where the Host expects the Guest to SEND_DMA console output to. */
#define LGUEST_CONSOLE_DMA_KEY 0
* complex burden for the Host and suboptimal for the Guest, so we have our own
* "lguest" bus and simple drivers.
*
- * Devices are described by an array of LGUEST_MAX_DEVICES of these structs,
- * placed by the Launcher just above the top of physical memory:
+ * Devices are described by a simplified ID, a status byte, and some "config"
+ * bytes which describe this device's configuration. This is placed by the
+ * Launcher just above the top of physical memory:
*/
struct lguest_device_desc {
- /* The device type: console, network, disk etc. */
- __u16 type;
-#define LGUEST_DEVICE_T_CONSOLE 1
-#define LGUEST_DEVICE_T_NET 2
-#define LGUEST_DEVICE_T_BLOCK 3
-
- /* The specific features of this device: these depends on device type
- * except for LGUEST_DEVICE_F_RANDOMNESS. */
- __u16 features;
-#define LGUEST_NET_F_NOCSUM 0x4000 /* Don't bother checksumming */
-#define LGUEST_DEVICE_F_RANDOMNESS 0x8000 /* IRQ is fairly random */
-
- /* This is how the Guest reports status of the device: the Host can set
- * LGUEST_DEVICE_S_REMOVED to indicate removal, but the rest are only
- * ever manipulated by the Guest, and only ever set. */
- __u16 status;
-/* 256 and above are device specific. */
-#define LGUEST_DEVICE_S_ACKNOWLEDGE 1 /* We have seen device. */
-#define LGUEST_DEVICE_S_DRIVER 2 /* We have found a driver */
-#define LGUEST_DEVICE_S_DRIVER_OK 4 /* Driver says OK! */
-#define LGUEST_DEVICE_S_REMOVED 8 /* Device has gone away. */
-#define LGUEST_DEVICE_S_REMOVED_ACK 16 /* Driver has been told. */
-#define LGUEST_DEVICE_S_FAILED 128 /* Something actually failed */
+ /* The device type: console, network, disk etc. Type 0 terminates. */
+ __u8 type;
+ /* The number of bytes of the config array. */
+ __u8 config_len;
+ /* A status byte, written by the Guest. */
+ __u8 status;
+ __u8 config[0];
+};
- /* Each device exists somewhere in Guest physical memory, over some
- * number of pages. */
- __u16 num_pages;
+/*D:135 This is how we expect the device configuration field for a virtqueue
+ * (type VIRTIO_CONFIG_F_VIRTQUEUE) to be laid out: */
+struct lguest_vqconfig {
+ /* The number of entries in the virtio_ring */
+ __u16 num;
+ /* The interrupt we get when something happens. */
+ __u16 irq;
+ /* The page number of the virtio ring for this device. */
__u32 pfn;
};
/*:*/
enum lguest_req
{
LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */
- LHREQ_GETDMA, /* + addr (returns &lguest_dma, irq in ->used_len) */
+ LHREQ_GETDMA, /* No longer used */
LHREQ_IRQ, /* + irq */
LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
};
git.openpandora.org / pandora-kernel.git / blobdiff