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Remove old lguest I/O infrrasructure.

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This patch gets rid of the old lguest host I/O infrastructure and
replaces it with a single hypercall "LHCALL_NOTIFY" which takes an
address.

The main change is the removal of io.c: that mainly did inter-guest
I/O, which virtio doesn't yet support.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2007-10-22 11:24:10 +10:00
parent 0ca49ca946
commit 15045275c3
8 changed files with 21 additions and 752 deletions
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36
include/linux/lguest_launcher.h
View file

@ -10,40 +10,6 @@
/* 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];
};
/*:*/
/* Where the Host expects the Guest to SEND_DMA console output to. */
#define LGUEST_CONSOLE_DMA_KEY 0
@ -95,7 +61,7 @@ struct lguest_device_desc {
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) */
};