-#ifndef _ASM_LGUEST_USER
-#define _ASM_LGUEST_USER
+#ifndef _LINUX_LGUEST_LAUNCHER
+#define _LINUX_LGUEST_LAUNCHER
/* Everything the "lguest" userspace program needs to know. */
-/* They can register up to 32 arrays of lguest_dma. */
-#define LGUEST_MAX_DMA 32
-/* At most we can dma 16 lguest_dma in one op. */
-#define LGUEST_MAX_DMA_SECTIONS 16
-
-/* How many devices? Assume each one wants up to two dma arrays per device. */
-#define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2)
-
-struct lguest_dma
-{
- /* 0 if free to be used, filled by hypervisor. */
- u32 used_len;
- unsigned long addr[LGUEST_MAX_DMA_SECTIONS];
- u16 len[LGUEST_MAX_DMA_SECTIONS];
-};
-
-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 */
-};
-
-/* There is a shared page of these. */
-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
-
-/* We have a page of these descriptors in the lguest_device page. */
+#include <linux/types.h>
+
+/*D:010
+ * Drivers
+ *
+ * The Guest needs devices to do anything useful. Since we don't let it touch
+ * real devices (think of the damage it could do!) we provide virtual devices.
+ * We could emulate a PCI bus with various devices on it, but that is a fairly
+ * complex burden for the Host and suboptimal for the Guest, so we have our own
+ * simple lguest bus and we use "virtio" drivers. These drivers need a set of
+ * routines from us which will actually do the virtual I/O, but they handle all
+ * the net/block/console stuff themselves. This means that if we want to add
+ * a new device, we simply need to write a new virtio driver and create support
+ * for it in the Launcher: this code won't need to change.
+ *
+ * Virtio devices are also used by kvm, so we can simply reuse their optimized
+ * device drivers. And one day when everyone uses virtio, my plan will be
+ * complete. Bwahahahah!
+ *
+ * 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 {
- u16 type;
-#define LGUEST_DEVICE_T_CONSOLE 1
-#define LGUEST_DEVICE_T_NET 2
-#define LGUEST_DEVICE_T_BLOCK 3
-
- u16 features;
-#define LGUEST_NET_F_NOCSUM 0x4000 /* Don't bother checksumming */
-#define LGUEST_DEVICE_F_RANDOMNESS 0x8000 /* IRQ is fairly random */
-
- 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 virtqueues (first in config array) */
+ __u8 num_vq;
+ /* The number of bytes of feature bits. Multiply by 2: one for host
+ * features and one for Guest acknowledgements. */
+ __u8 feature_len;
+ /* The number of bytes of the config array after virtqueues. */
+ __u8 config_len;
+ /* A status byte, written by the Guest. */
+ __u8 status;
+ __u8 config[0];
+};
- u16 num_pages;
- u32 pfn;
+/*D:135 This is how we expect the device configuration field for a virtqueue
+ * to be laid out in config space. */
+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;
};
+/*:*/
/* Write command first word is a request. */
enum lguest_req
{
- LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */
- LHREQ_GETDMA, /* + addr (returns &lguest_dma, irq in ->used_len) */
+ LHREQ_INITIALIZE, /* + base, pfnlimit, pgdir, start */
+ LHREQ_GETDMA, /* No longer used */
LHREQ_IRQ, /* + irq */
LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
};
-#endif /* _ASM_LGUEST_USER */
+#endif /* _LINUX_LGUEST_LAUNCHER */