#include "linux/virtio_console.h"
#include "linux/virtio_rng.h"
#include "linux/virtio_ring.h"
-#include "asm-x86/bootparam.h"
+#include "asm/bootparam.h"
/*L:110 We can ignore the 39 include files we need for this program, but I do
* want to draw attention to the use of kernel-style types.
*
/* We return the initrd size. */
return len;
}
-
-/* Once we know how much memory we have we can construct simple linear page
- * tables which set virtual == physical which will get the Guest far enough
- * into the boot to create its own.
- *
- * We lay them out of the way, just below the initrd (which is why we need to
- * know its size here). */
-static unsigned long setup_pagetables(unsigned long mem,
- unsigned long initrd_size)
-{
- unsigned long *pgdir, *linear;
- unsigned int mapped_pages, i, linear_pages;
- unsigned int ptes_per_page = getpagesize()/sizeof(void *);
-
- mapped_pages = mem/getpagesize();
-
- /* Each PTE page can map ptes_per_page pages: how many do we need? */
- linear_pages = (mapped_pages + ptes_per_page-1)/ptes_per_page;
-
- /* We put the toplevel page directory page at the top of memory. */
- pgdir = from_guest_phys(mem) - initrd_size - getpagesize();
-
- /* Now we use the next linear_pages pages as pte pages */
- linear = (void *)pgdir - linear_pages*getpagesize();
-
- /* Linear mapping is easy: put every page's address into the mapping in
- * order. PAGE_PRESENT contains the flags Present, Writable and
- * Executable. */
- for (i = 0; i < mapped_pages; i++)
- linear[i] = ((i * getpagesize()) | PAGE_PRESENT);
-
- /* The top level points to the linear page table pages above. */
- for (i = 0; i < mapped_pages; i += ptes_per_page) {
- pgdir[i/ptes_per_page]
- = ((to_guest_phys(linear) + i*sizeof(void *))
- | PAGE_PRESENT);
- }
-
- verbose("Linear mapping of %u pages in %u pte pages at %#lx\n",
- mapped_pages, linear_pages, to_guest_phys(linear));
-
- /* We return the top level (guest-physical) address: the kernel needs
- * to know where it is. */
- return to_guest_phys(pgdir);
-}
/*:*/
/* Simple routine to roll all the commandline arguments together with spaces
/*L:185 This is where we actually tell the kernel to initialize the Guest. We
* saw the arguments it expects when we looked at initialize() in lguest_user.c:
- * the base of Guest "physical" memory, the top physical page to allow, the
- * top level pagetable and the entry point for the Guest. */
-static int tell_kernel(unsigned long pgdir, unsigned long start)
+ * the base of Guest "physical" memory, the top physical page to allow and the
+ * entry point for the Guest. */
+static int tell_kernel(unsigned long start)
{
unsigned long args[] = { LHREQ_INITIALIZE,
(unsigned long)guest_base,
- guest_limit / getpagesize(), pgdir, start };
+ guest_limit / getpagesize(), start };
int fd;
verbose("Guest: %p - %p (%#lx)\n",
/* 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) {
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);
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;
}
}
+ /* OK, so we noted that it was pretty poor to use an fdatasync as a
+ * barrier. But Christoph Hellwig points out that we need a sync
+ * *afterwards* as well: "Barriers specify no reordering to the front
+ * or the back." And Jens Axboe confirmed it, so here we are: */
+ if (out->type & VIRTIO_BLK_T_BARRIER)
+ fdatasync(vblk->fd);
+
/* We can't trigger an IRQ, because we're not the Launcher. It does
* that when we tell it we're done. */
add_used(dev->vq, head, wlen);
{
/* Memory, top-level pagetable, code startpoint and size of the
* (optional) initrd. */
- unsigned long mem = 0, pgdir, start, initrd_size = 0;
+ unsigned long mem = 0, start, initrd_size = 0;
/* Two temporaries and the /dev/lguest file descriptor. */
int i, c, lguest_fd;
/* The boot information for the Guest. */
boot->hdr.type_of_loader = 0xFF;
}
- /* Set up the initial linear pagetables, starting below the initrd. */
- pgdir = setup_pagetables(mem, initrd_size);
-
/* The Linux boot header contains an "E820" memory map: ours is a
* simple, single region. */
boot->e820_entries = 1;
/* We tell the kernel to initialize the Guest: this returns the open
* /dev/lguest file descriptor. */
- lguest_fd = tell_kernel(pgdir, start);
+ lguest_fd = tell_kernel(start);
/* We clone off a thread, which wakes the Launcher whenever one of the
* input file descriptors needs attention. We call this the Waker, and