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Diffstat (limited to 'Documentation/lguest/lguest.c')
-rw-r--r--Documentation/lguest/lguest.c84
1 files changed, 34 insertions, 50 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 1432b502a2d..62a8133393e 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -47,12 +47,14 @@ static bool verbose;
#define verbose(args...) \
do { if (verbose) printf(args); } while(0)
static int waker_fd;
+static u32 top;
struct device_list
{
fd_set infds;
int max_infd;
+ struct lguest_device_desc *descs;
struct device *dev;
struct device **lastdev;
};
@@ -324,8 +326,7 @@ static void concat(char *dst, char *args[])
static int tell_kernel(u32 pgdir, u32 start, u32 page_offset)
{
u32 args[] = { LHREQ_INITIALIZE,
- LGUEST_GUEST_TOP/getpagesize(), /* Just below us */
- pgdir, start, page_offset };
+ top/getpagesize(), pgdir, start, page_offset };
int fd;
fd = open_or_die("/dev/lguest", O_RDWR);
@@ -382,7 +383,7 @@ static int setup_waker(int lguest_fd, struct device_list *device_list)
static void *_check_pointer(unsigned long addr, unsigned int size,
unsigned int line)
{
- if (addr >= LGUEST_GUEST_TOP || addr + size >= LGUEST_GUEST_TOP)
+ if (addr >= top || addr + size >= top)
errx(1, "%s:%i: Invalid address %li", __FILE__, line, addr);
return (void *)addr;
}
@@ -629,24 +630,26 @@ static void handle_input(int fd, struct device_list *devices)
}
}
-static struct lguest_device_desc *new_dev_desc(u16 type, u16 features,
- u16 num_pages)
+static struct lguest_device_desc *
+new_dev_desc(struct lguest_device_desc *descs,
+ u16 type, u16 features, u16 num_pages)
{
- static unsigned long top = LGUEST_GUEST_TOP;
- struct lguest_device_desc *desc;
+ unsigned int i;
- desc = malloc(sizeof(*desc));
- desc->type = type;
- desc->num_pages = num_pages;
- desc->features = features;
- desc->status = 0;
- if (num_pages) {
- top -= num_pages*getpagesize();
- map_zeroed_pages(top, num_pages);
- desc->pfn = top / getpagesize();
- } else
- desc->pfn = 0;
- return desc;
+ for (i = 0; i < LGUEST_MAX_DEVICES; i++) {
+ if (!descs[i].type) {
+ descs[i].type = type;
+ descs[i].features = features;
+ descs[i].num_pages = num_pages;
+ if (num_pages) {
+ map_zeroed_pages(top, num_pages);
+ descs[i].pfn = top/getpagesize();
+ top += num_pages*getpagesize();
+ }
+ return &descs[i];
+ }
+ }
+ errx(1, "too many devices");
}
static struct device *new_device(struct device_list *devices,
@@ -669,7 +672,7 @@ static struct device *new_device(struct device_list *devices,
dev->fd = fd;
if (handle_input)
set_fd(dev->fd, devices);
- dev->desc = new_dev_desc(type, features, num_pages);
+ dev->desc = new_dev_desc(devices->descs, type, features, num_pages);
dev->mem = (void *)(dev->desc->pfn * getpagesize());
dev->handle_input = handle_input;
dev->watch_key = (unsigned long)dev->mem + watch_off;
@@ -866,30 +869,6 @@ static void setup_tun_net(const char *arg, struct device_list *devices)
verbose("attached to bridge: %s\n", br_name);
}
-/* Now we know how much memory we have, we copy in device descriptors */
-static void map_device_descriptors(struct device_list *devs, unsigned long mem)
-{
- struct device *i;
- unsigned int num;
- struct lguest_device_desc *descs;
-
- /* Device descriptor array sits just above top of normal memory */
- descs = map_zeroed_pages(mem, 1);
-
- for (i = devs->dev, num = 0; i; i = i->next, num++) {
- if (num == LGUEST_MAX_DEVICES)
- errx(1, "too many devices");
- verbose("Device %i: %s\n", num,
- i->desc->type == LGUEST_DEVICE_T_NET ? "net"
- : i->desc->type == LGUEST_DEVICE_T_CONSOLE ? "console"
- : i->desc->type == LGUEST_DEVICE_T_BLOCK ? "block"
- : "unknown");
- descs[num] = *i->desc;
- free(i->desc);
- i->desc = &descs[num];
- }
-}
-
static void __attribute__((noreturn))
run_guest(int lguest_fd, struct device_list *device_list)
{
@@ -934,8 +913,8 @@ static void usage(void)
int main(int argc, char *argv[])
{
- unsigned long mem, pgdir, start, page_offset, initrd_size = 0;
- int c, lguest_fd;
+ unsigned long mem = 0, pgdir, start, page_offset, initrd_size = 0;
+ int i, c, lguest_fd;
struct device_list device_list;
void *boot = (void *)0;
const char *initrd_name = NULL;
@@ -945,6 +924,15 @@ int main(int argc, char *argv[])
device_list.lastdev = &device_list.dev;
FD_ZERO(&device_list.infds);
+ /* We need to know how much memory so we can allocate devices. */
+ for (i = 1; i < argc; i++) {
+ if (argv[i][0] != '-') {
+ mem = top = atoi(argv[i]) * 1024 * 1024;
+ device_list.descs = map_zeroed_pages(top, 1);
+ top += getpagesize();
+ break;
+ }
+ }
while ((c = getopt_long(argc, argv, "v", opts, NULL)) != EOF) {
switch (c) {
case 'v':
@@ -974,16 +962,12 @@ int main(int argc, char *argv[])
setup_console(&device_list);
/* First we map /dev/zero over all of guest-physical memory. */
- mem = atoi(argv[optind]) * 1024 * 1024;
map_zeroed_pages(0, mem / getpagesize());
/* Now we load the kernel */
start = load_kernel(open_or_die(argv[optind+1], O_RDONLY),
&page_offset);
- /* Write the device descriptors into memory. */
- map_device_descriptors(&device_list, mem);
-
/* Map the initrd image if requested */
if (initrd_name) {
initrd_size = load_initrd(initrd_name, mem);