diff options
| -rw-r--r-- | include/linux/lguest_launcher.h | 49 |
1 files changed, 2 insertions, 47 deletions
diff --git a/include/linux/lguest_launcher.h b/include/linux/lguest_launcher.h index 3c402b843e03..677cde735d4b 100644 --- a/include/linux/lguest_launcher.h +++ b/include/linux/lguest_launcher.h | |||
| @@ -8,52 +8,13 @@ | |||
| 8 | * | 8 | * |
| 9 | * The Guest needs devices to do anything useful. Since we don't let it touch | 9 | * The Guest needs devices to do anything useful. Since we don't let it touch |
| 10 | * real devices (think of the damage it could do!) we provide virtual devices. | 10 | * real devices (think of the damage it could do!) we provide virtual devices. |
| 11 | * We could emulate a PCI bus with various devices on it, but that is a fairly | 11 | * We emulate a PCI bus with virtio devices on it; we used to have our own |
| 12 | * complex burden for the Host and suboptimal for the Guest, so we have our own | 12 | * lguest bus which was far simpler, but this tests the virtio 1.0 standard. |
| 13 | * simple lguest bus and we use "virtio" drivers. These drivers need a set of | ||
| 14 | * routines from us which will actually do the virtual I/O, but they handle all | ||
| 15 | * the net/block/console stuff themselves. This means that if we want to add | ||
| 16 | * a new device, we simply need to write a new virtio driver and create support | ||
| 17 | * for it in the Launcher: this code won't need to change. | ||
| 18 | * | 13 | * |
| 19 | * Virtio devices are also used by kvm, so we can simply reuse their optimized | 14 | * Virtio devices are also used by kvm, so we can simply reuse their optimized |
| 20 | * device drivers. And one day when everyone uses virtio, my plan will be | 15 | * device drivers. And one day when everyone uses virtio, my plan will be |
| 21 | * complete. Bwahahahah! | 16 | * complete. Bwahahahah! |
| 22 | * | ||
| 23 | * Devices are described by a simplified ID, a status byte, and some "config" | ||
| 24 | * bytes which describe this device's configuration. This is placed by the | ||
| 25 | * Launcher just above the top of physical memory: | ||
| 26 | */ | ||
| 27 | struct lguest_device_desc { | ||
| 28 | /* The device type: console, network, disk etc. Type 0 terminates. */ | ||
| 29 | __u8 type; | ||
| 30 | /* The number of virtqueues (first in config array) */ | ||
| 31 | __u8 num_vq; | ||
| 32 | /* | ||
| 33 | * The number of bytes of feature bits. Multiply by 2: one for host | ||
| 34 | * features and one for Guest acknowledgements. | ||
| 35 | */ | ||
| 36 | __u8 feature_len; | ||
| 37 | /* The number of bytes of the config array after virtqueues. */ | ||
| 38 | __u8 config_len; | ||
| 39 | /* A status byte, written by the Guest. */ | ||
| 40 | __u8 status; | ||
| 41 | __u8 config[0]; | ||
| 42 | }; | ||
| 43 | |||
| 44 | /*D:135 | ||
| 45 | * This is how we expect the device configuration field for a virtqueue | ||
| 46 | * to be laid out in config space. | ||
| 47 | */ | 17 | */ |
| 48 | struct lguest_vqconfig { | ||
| 49 | /* The number of entries in the virtio_ring */ | ||
| 50 | __u16 num; | ||
| 51 | /* The interrupt we get when something happens. */ | ||
| 52 | __u16 irq; | ||
| 53 | /* The page number of the virtio ring for this device. */ | ||
| 54 | __u32 pfn; | ||
| 55 | }; | ||
| 56 | /*:*/ | ||
| 57 | 18 | ||
| 58 | /* Write command first word is a request. */ | 19 | /* Write command first word is a request. */ |
| 59 | enum lguest_req | 20 | enum lguest_req |
| @@ -80,10 +41,4 @@ struct lguest_pending { | |||
| 80 | __u8 insn[7]; | 41 | __u8 insn[7]; |
| 81 | __u32 addr; | 42 | __u32 addr; |
| 82 | }; | 43 | }; |
| 83 | |||
| 84 | /* | ||
| 85 | * The alignment to use between consumer and producer parts of vring. | ||
| 86 | * x86 pagesize for historical reasons. | ||
| 87 | */ | ||
| 88 | #define LGUEST_VRING_ALIGN 4096 | ||
| 89 | #endif /* _LINUX_LGUEST_LAUNCHER */ | 44 | #endif /* _LINUX_LGUEST_LAUNCHER */ |
