KVM: MMU: Simplify calculation of pte access

[linux-2.6] / Documentation / lguest / lguest.c

diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index f2668390e8f773276357917e79625790d4e98b5a..9b0e322118b5402eb83868c70266f8afdf420ed1 100644 (file)
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -62,8 +62,8 @@ typedef uint8_t u8;
 #endif
 /* We can have up to 256 pages for devices. */
 #define DEVICE_PAGES 256
-/* This fits nicely in a single 4096-byte page. */
-#define VIRTQUEUE_NUM 127
+/* This will occupy 2 pages: it must be a power of 2. */
+#define VIRTQUEUE_NUM 128
 
 /*L:120 verbose is both a global flag and a macro.  The C preprocessor allows
  * this, and although I wouldn't recommend it, it works quite nicely here. */
@@ -1036,16 +1036,22 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
        void *p;
 
        /* First we need some pages for this virtqueue. */
-       pages = (vring_size(num_descs) + getpagesize() - 1) / getpagesize();
+       pages = (vring_size(num_descs, getpagesize()) + getpagesize() - 1)
+               / getpagesize();
        p = get_pages(pages);
 
+       /* Initialize the virtqueue */
+       vq->next = NULL;
+       vq->last_avail_idx = 0;
+       vq->dev = dev;
+
        /* Initialize the configuration. */
        vq->config.num = num_descs;
        vq->config.irq = devices.next_irq++;
        vq->config.pfn = to_guest_phys(p) / getpagesize();
 
        /* Initialize the vring. */
-       vring_init(&vq->vring, num_descs, p);
+       vring_init(&vq->vring, num_descs, p, getpagesize());
 
        /* Add the configuration information to this device's descriptor. */
        add_desc_field(dev, VIRTIO_CONFIG_F_VIRTQUEUE,
@@ -1056,9 +1062,6 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
        for (i = &dev->vq; *i; i = &(*i)->next);
        *i = vq;
 
-       /* Link virtqueue back to device. */
-       vq->dev = dev;
-
        /* Set the routine to call when the Guest does something to this
         * virtqueue. */
        vq->handle_output = handle_output;
@@ -1092,6 +1095,7 @@ static struct device *new_device(const char *name, u16 type, int fd,
        dev->desc = new_dev_desc(type);
        dev->handle_input = handle_input;
        dev->name = name;
+       dev->vq = NULL;
        return dev;
 }
 
@@ -1342,7 +1346,7 @@ static bool service_io(struct device *dev)
        if (out->type & VIRTIO_BLK_T_SCSI_CMD) {
                fprintf(stderr, "Scsi commands unsupported\n");
                in->status = VIRTIO_BLK_S_UNSUPP;
-               wlen = sizeof(in);
+               wlen = sizeof(*in);
        } else if (out->type & VIRTIO_BLK_T_OUT) {
                /* Write */
 
@@ -1363,7 +1367,7 @@ static bool service_io(struct device *dev)
                        /* Die, bad Guest, die. */
                        errx(1, "Write past end %llu+%u", off, ret);
                }
-               wlen = sizeof(in);
+               wlen = sizeof(*in);
                in->status = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
        } else {
                /* Read */
@@ -1376,10 +1380,10 @@ static bool service_io(struct device *dev)
                ret = readv(vblk->fd, iov+1, in_num-1);
                verbose("READ from sector %llu: %i\n", out->sector, ret);
                if (ret >= 0) {
-                       wlen = sizeof(in) + ret;
+                       wlen = sizeof(*in) + ret;
                        in->status = VIRTIO_BLK_S_OK;
                } else {
-                       wlen = sizeof(in);
+                       wlen = sizeof(*in);
                        in->status = VIRTIO_BLK_S_IOERR;
                }
        }