Commit 2966af73 authored by Rusty Russell's avatar Rusty Russell

virtio: use LGUEST_VRING_ALIGN instead of relying on pagesize

This doesn't really matter, since lguest is i386 only at the moment,
but we could actually choose a different value.  (lguest doesn't have
a guarenteed ABI).
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 498af147
......@@ -1030,7 +1030,7 @@ static void update_device_status(struct device *dev)
/* Zero out the virtqueues. */
for (vq = dev->vq; vq; vq = vq->next) {
memset(vq->vring.desc, 0,
vring_size(vq->config.num, getpagesize()));
vring_size(vq->config.num, LGUEST_VRING_ALIGN));
lg_last_avail(vq) = 0;
}
} else if (dev->desc->status & VIRTIO_CONFIG_S_FAILED) {
......@@ -1211,7 +1211,7 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
void *p;
/* First we need some memory for this virtqueue. */
pages = (vring_size(num_descs, getpagesize()) + getpagesize() - 1)
pages = (vring_size(num_descs, LGUEST_VRING_ALIGN) + getpagesize() - 1)
/ getpagesize();
p = get_pages(pages);
......@@ -1228,7 +1228,7 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs,
vq->config.pfn = to_guest_phys(p) / getpagesize();
/* Initialize the vring. */
vring_init(&vq->vring, num_descs, p, getpagesize());
vring_init(&vq->vring, num_descs, p, LGUEST_VRING_ALIGN);
/* Append virtqueue to this device's descriptor. We use
* device_config() to get the end of the device's current virtqueues;
......
......@@ -250,7 +250,7 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
/* Figure out how many pages the ring will take, and map that memory */
lvq->pages = lguest_map((unsigned long)lvq->config.pfn << PAGE_SHIFT,
DIV_ROUND_UP(vring_size(lvq->config.num,
PAGE_SIZE),
LGUEST_VRING_ALIGN),
PAGE_SIZE));
if (!lvq->pages) {
err = -ENOMEM;
......
......@@ -59,4 +59,8 @@ enum lguest_req
LHREQ_IRQ, /* + irq */
LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
};
/* The alignment to use between consumer and producer parts of vring.
* x86 pagesize for historical reasons. */
#define LGUEST_VRING_ALIGN 4096
#endif /* _LINUX_LGUEST_LAUNCHER */
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