#ifndef _ASM_LGUEST_USER #define _ASM_LGUEST_USER /* Everything the "lguest" userspace program needs to know. */ #include /* 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) /* Where the Host expects the Guest to SEND_DMA console output to. */ #define LGUEST_CONSOLE_DMA_KEY 0 /*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 * "lguest" bus and simple drivers. * * 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. 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]; }; /*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; }; /*:*/ /* Write command first word is a request. */ enum lguest_req { LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */ LHREQ_GETDMA, /* No longer used */ LHREQ_IRQ, /* + irq */ LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */ }; #endif /* _ASM_LGUEST_USER */