1 files changed, 34 insertions, 50 deletions

diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 1432b502a2d9..62a8133393e1 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);