Remove fixed limit on number of guests, and lguests array.

Back when we had all the Guest state in the switcher, we had a fixed
array of them.  This is no longer necessary.

If we switch the network code to using random_ether_addr (46 bits is
enough to avoid clashes), we can get rid of the concept of "guest id"
altogether.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2007-10-22 11:03:27 +10:00
parent 3c6b5bfa3c
commit 48245cc070
7 changed files with 14 additions and 45 deletions

View File

@ -47,10 +47,6 @@ static struct {
DEFINE_MUTEX(lguest_lock);
static DEFINE_PER_CPU(struct lguest *, last_guest);
/* FIXME: Make dynamic. */
#define MAX_LGUEST_GUESTS 16
struct lguest lguests[MAX_LGUEST_GUESTS];
/* Offset from where switcher.S was compiled to where we've copied it */
static unsigned long switcher_offset(void)
{
@ -660,16 +656,6 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
* deliver_trap() and demand_page(). After all those, we'll be ready to
* examine the Switcher, and our philosophical understanding of the Host/Guest
* duality will be complete. :*/
int find_free_guest(void)
{
unsigned int i;
for (i = 0; i < MAX_LGUEST_GUESTS; i++)
if (!lguests[i].tsk)
return i;
return -1;
}
static void adjust_pge(void *on)
{
if (on)

View File

@ -225,9 +225,7 @@ static void initialize(struct lguest *lg)
/* We tell the Guest that it can't use the top 4MB of virtual
* addresses used by the Switcher. */
|| put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
|| put_user(tsc_speed, &lg->lguest_data->tsc_khz)
/* We also give the Guest a unique id, as used in lguest_net.c. */
|| put_user(lg->guestid, &lg->lguest_data->guestid))
|| put_user(tsc_speed, &lg->lguest_data->tsc_khz))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
/* We write the current time into the Guest's data page once now. */

View File

@ -212,7 +212,7 @@ int bind_dma(struct lguest *lg,
lg->dma[i].num_dmas = numdmas;
lg->dma[i].next_dma = 0;
lg->dma[i].key = key;
lg->dma[i].guestid = lg->guestid;
lg->dma[i].owner = lg;
lg->dma[i].interrupt = interrupt;
/* Now we add it to the hash table: the position
@ -412,7 +412,7 @@ static int dma_transfer(struct lguest *srclg,
/* From the "struct lguest_dma_info" we found in the hash, grab the
* Guest. */
dstlg = &lguests[dst->guestid];
dstlg = dst->owner;
/* Read in the source "struct lguest_dma" handed to SEND_DMA. */
lgread(srclg, &src_dma, udma, sizeof(src_dma));
@ -506,8 +506,8 @@ again:
struct lguest_dma_info *i;
/* Look through the hash for other Guests. */
list_for_each_entry(i, &dma_hash[hash(&key)], list) {
/* Don't send to ourselves. */
if (i->guestid == lg->guestid)
/* Don't send to ourselves (would deadlock). */
if (i->owner->mm == lg->mm)
continue;
if (!key_eq(&key, &i->key))
continue;
@ -594,7 +594,7 @@ unsigned long get_dma_buffer(struct lguest *lg,
* send to its own Guest for the moment, so the entry must be for this
* Guest) */
list_for_each_entry(i, &dma_hash[hash(&key)], list) {
if (key_eq(&key, &i->key) && i->guestid == lg->guestid) {
if (key_eq(&key, &i->key) && i->owner == lg) {
unsigned int j;
/* Look through the registered DMA array for an
* available buffer. */

View File

@ -51,9 +51,9 @@ struct lguest_dma_info
struct list_head list;
union futex_key key;
unsigned long dmas;
struct lguest *owner;
u16 next_dma;
u16 num_dmas;
u16 guestid;
u8 interrupt; /* 0 when not registered */
};
@ -140,7 +140,6 @@ struct lguest
struct lguest_data __user *lguest_data;
struct task_struct *tsk;
struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
u16 guestid;
u32 pfn_limit;
/* This provides the offset to the base of guest-physical
* memory in the Launcher. */
@ -195,7 +194,6 @@ struct lguest
DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
};
extern struct lguest lguests[];
extern struct mutex lguest_lock;
/* core.c: */
@ -203,7 +201,6 @@ u32 lgread_u32(struct lguest *lg, unsigned long addr);
void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
int find_free_guest(void);
int lguest_address_ok(const struct lguest *lg,
unsigned long addr, unsigned long len);
int run_guest(struct lguest *lg, unsigned long __user *user);

View File

@ -167,11 +167,11 @@ static int initialize(struct file *file, const u32 __user *input)
/* "struct lguest" contains everything we (the Host) know about a
* Guest. */
struct lguest *lg;
int err, i;
int err;
u32 args[5];
/* We grab the Big Lguest lock, which protects the global array
* "lguests" and multiple simultaneous initializations. */
/* We grab the Big Lguest lock, which protects against multiple
* simultaneous initializations. */
mutex_lock(&lguest_lock);
/* You can't initialize twice! Close the device and start again... */
if (file->private_data) {
@ -184,18 +184,13 @@ static int initialize(struct file *file, const u32 __user *input)
goto unlock;
}
/* Find an unused guest. */
i = find_free_guest();
if (i < 0) {
err = -ENOSPC;
lg = kzalloc(sizeof(*lg), GFP_KERNEL);
if (!lg) {
err = -ENOMEM;
goto unlock;
}
/* OK, we have an index into the "lguest" array: "lg" is a convenient
* pointer. */
lg = &lguests[i];
/* Populate the easy fields of our "struct lguest" */
lg->guestid = i;
lg->mem_base = (void __user *)(long)args[0];
lg->pfn_limit = args[1];
lg->page_offset = args[4];

View File

@ -463,12 +463,7 @@ static int lguestnet_probe(struct lguest_device *lgdev)
/* Ethernet defaults with some changes */
ether_setup(dev);
dev->set_mac_address = NULL;
dev->dev_addr[0] = 0x02; /* set local assignment bit (IEEE802) */
dev->dev_addr[1] = 0x00;
memcpy(&dev->dev_addr[2], &lguest_data.guestid, 2);
dev->dev_addr[4] = 0x00;
dev->dev_addr[5] = 0x00;
random_ether_addr(dev->dev_addr);
dev->open = lguestnet_open;
dev->stop = lguestnet_close;

View File

@ -41,8 +41,6 @@ struct lguest_data
/* Fields initialized by the Host at boot: */
/* Memory not to try to access */
unsigned long reserve_mem;
/* ID of this Guest (used by network driver to set ethernet address) */
u16 guestid;
/* KHz for the TSC clock. */
u32 tsc_khz;