From 19f1537b7b8a9a82665db3ad8210a9d954d13acd Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Oct 2007 11:24:21 +1000 Subject: Lguest support for Virtio This makes lguest able to use the virtio devices. We change the device descriptor page from a simple array to a variable length "type, config_len, status, config data..." format, and implement virtio_config_ops to read from that config data. We use the virtio ring implementation for an efficient Guest <-> Host virtqueue mechanism, and the new LHCALL_NOTIFY hypercall to kick the host when it changes. We also use LHCALL_NOTIFY on kernel addresses for very very early console output. We could have another hypercall, but this hack works quite well. Signed-off-by: Rusty Russell --- include/linux/lguest_launcher.h | 47 +++++++++++++++++------------------------ 1 file changed, 19 insertions(+), 28 deletions(-) (limited to 'include/linux/lguest_launcher.h') diff --git a/include/linux/lguest_launcher.h b/include/linux/lguest_launcher.h index 5ec04a2..61e1e3e 100644 --- a/include/linux/lguest_launcher.h +++ b/include/linux/lguest_launcher.h @@ -22,37 +22,28 @@ * 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; }; /*:*/ -- cgit v1.1