* (vii) Setting up the page tables initially.
:*/
-/* Pages a 4k long, and each page table entry is 4 bytes long, giving us 1024
- * (or 2^10) entries per page. */
-#define PTES_PER_PAGE_SHIFT 10
-#define PTES_PER_PAGE (1 << PTES_PER_PAGE_SHIFT)
/* 1024 entries in a page table page maps 1024 pages: 4MB. The Switcher is
* conveniently placed at the top 4MB, so it uses a separate, complete PTE
* page. */
-#define SWITCHER_PGD_INDEX (PTES_PER_PAGE - 1)
+#define SWITCHER_PGD_INDEX (PTRS_PER_PGD - 1)
/* We actually need a separate PTE page for each CPU. Remember that after the
* Switcher code itself comes two pages for each CPU, and we don't want this
* CPU's guest to see the pages of any other CPU. */
-static DEFINE_PER_CPU(spte_t *, switcher_pte_pages);
+static DEFINE_PER_CPU(pte_t *, switcher_pte_pages);
#define switcher_pte_page(cpu) per_cpu(switcher_pte_pages, cpu)
/*H:320 With our shadow and Guest types established, we need to deal with
* them: the page table code is curly enough to need helper functions to keep
* it clear and clean.
*
- * The first helper takes a virtual address, and says which entry in the top
- * level page table deals with that address. Since each top level entry deals
- * with 4M, this effectively divides by 4M. */
-static unsigned vaddr_to_pgd_index(unsigned long vaddr)
-{
- return vaddr >> (PAGE_SHIFT + PTES_PER_PAGE_SHIFT);
-}
-
-/* There are two functions which return pointers to the shadow (aka "real")
+ * There are two functions which return pointers to the shadow (aka "real")
* page tables.
*
* spgd_addr() takes the virtual address and returns a pointer to the top-level
* page directory entry for that address. Since we keep track of several page
* tables, the "i" argument tells us which one we're interested in (it's
* usually the current one). */
-static spgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
+static pgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
{
- unsigned int index = vaddr_to_pgd_index(vaddr);
+ unsigned int index = pgd_index(vaddr);
/* We kill any Guest trying to touch the Switcher addresses. */
if (index >= SWITCHER_PGD_INDEX) {
/* This routine then takes the PGD entry given above, which contains the
* address of the PTE page. It then returns a pointer to the PTE entry for the
* given address. */
-static spte_t *spte_addr(struct lguest *lg, spgd_t spgd, unsigned long vaddr)
+static pte_t *spte_addr(struct lguest *lg, pgd_t spgd, unsigned long vaddr)
{
- spte_t *page = __va(spgd.pfn << PAGE_SHIFT);
+ pte_t *page = __va(pgd_pfn(spgd) << PAGE_SHIFT);
/* You should never call this if the PGD entry wasn't valid */
- BUG_ON(!(spgd.flags & _PAGE_PRESENT));
- return &page[(vaddr >> PAGE_SHIFT) % PTES_PER_PAGE];
+ BUG_ON(!(pgd_flags(spgd) & _PAGE_PRESENT));
+ return &page[(vaddr >> PAGE_SHIFT) % PTRS_PER_PTE];
}
/* These two functions just like the above two, except they access the Guest
* page tables. Hence they return a Guest address. */
static unsigned long gpgd_addr(struct lguest *lg, unsigned long vaddr)
{
- unsigned int index = vaddr >> (PAGE_SHIFT + PTES_PER_PAGE_SHIFT);
- return lg->pgdirs[lg->pgdidx].cr3 + index * sizeof(gpgd_t);
+ unsigned int index = vaddr >> (PGDIR_SHIFT);
+ return lg->pgdirs[lg->pgdidx].cr3 + index * sizeof(pgd_t);
}
static unsigned long gpte_addr(struct lguest *lg,
- gpgd_t gpgd, unsigned long vaddr)
+ pgd_t gpgd, unsigned long vaddr)
{
- unsigned long gpage = gpgd.pfn << PAGE_SHIFT;
- BUG_ON(!(gpgd.flags & _PAGE_PRESENT));
- return gpage + ((vaddr>>PAGE_SHIFT) % PTES_PER_PAGE) * sizeof(gpte_t);
+ unsigned long gpage = pgd_pfn(gpgd) << PAGE_SHIFT;
+ BUG_ON(!(pgd_flags(gpgd) & _PAGE_PRESENT));
+ return gpage + ((vaddr>>PAGE_SHIFT) % PTRS_PER_PTE) * sizeof(pte_t);
}
/*H:350 This routine takes a page number given by the Guest and converts it to
* entry can be a little tricky. The flags are (almost) the same, but the
* Guest PTE contains a virtual page number: the CPU needs the real page
* number. */
-static spte_t gpte_to_spte(struct lguest *lg, gpte_t gpte, int write)
+static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
{
- spte_t spte;
- unsigned long pfn, base;
+ unsigned long pfn, base, flags;
/* The Guest sets the global flag, because it thinks that it is using
* PGE. We only told it to use PGE so it would tell us whether it was
* flushing a kernel mapping or a userspace mapping. We don't actually
* use the global bit, so throw it away. */
- spte.flags = (gpte.flags & ~_PAGE_GLOBAL);
+ flags = (pte_flags(gpte) & ~_PAGE_GLOBAL);
/* The Guest's pages are offset inside the Launcher. */
base = (unsigned long)lg->mem_base / PAGE_SIZE;
* get_pfn(), because it returns 0xFFFFFFFF on failure, which wouldn't
* fit in spte.pfn. get_pfn() finds the real physical number of the
* page, given the virtual number. */
- pfn = get_pfn(base + gpte.pfn, write);
+ pfn = get_pfn(base + pte_pfn(gpte), write);
if (pfn == -1UL) {
- kill_guest(lg, "failed to get page %u", gpte.pfn);
+ kill_guest(lg, "failed to get page %lu", pte_pfn(gpte));
/* When we destroy the Guest, we'll go through the shadow page
* tables and release_pte() them. Make sure we don't think
* this one is valid! */
- spte.flags = 0;
+ flags = 0;
}
- /* Now we assign the page number, and our shadow PTE is complete. */
- spte.pfn = pfn;
- return spte;
+ /* Now we assemble our shadow PTE from the page number and flags. */
+ return pfn_pte(pfn, __pgprot(flags));
}
/*H:460 And to complete the chain, release_pte() looks like this: */
-static void release_pte(spte_t pte)
+static void release_pte(pte_t pte)
{
/* Remember that get_user_pages() took a reference to the page, in
* get_pfn()? We have to put it back now. */
- if (pte.flags & _PAGE_PRESENT)
- put_page(pfn_to_page(pte.pfn));
+ if (pte_flags(pte) & _PAGE_PRESENT)
+ put_page(pfn_to_page(pte_pfn(pte)));
}
/*:*/
-static void check_gpte(struct lguest *lg, gpte_t gpte)
+static void check_gpte(struct lguest *lg, pte_t gpte)
{
- if ((gpte.flags & (_PAGE_PWT|_PAGE_PSE)) || gpte.pfn >= lg->pfn_limit)
+ if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE))
+ || pte_pfn(gpte) >= lg->pfn_limit)
kill_guest(lg, "bad page table entry");
}
-static void check_gpgd(struct lguest *lg, gpgd_t gpgd)
+static void check_gpgd(struct lguest *lg, pgd_t gpgd)
{
- if ((gpgd.flags & ~_PAGE_TABLE) || gpgd.pfn >= lg->pfn_limit)
+ if ((pgd_flags(gpgd) & ~_PAGE_TABLE) || pgd_pfn(gpgd) >= lg->pfn_limit)
kill_guest(lg, "bad page directory entry");
}
* true. */
int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
{
- gpgd_t gpgd;
- spgd_t *spgd;
+ pgd_t gpgd;
+ pgd_t *spgd;
unsigned long gpte_ptr;
- gpte_t gpte;
- spte_t *spte;
+ pte_t gpte;
+ pte_t *spte;
/* First step: get the top-level Guest page table entry. */
- gpgd = mkgpgd(lgread_u32(lg, gpgd_addr(lg, vaddr)));
+ gpgd = __pgd(lgread_u32(lg, gpgd_addr(lg, vaddr)));
/* Toplevel not present? We can't map it in. */
- if (!(gpgd.flags & _PAGE_PRESENT))
+ if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
return 0;
/* Now look at the matching shadow entry. */
spgd = spgd_addr(lg, lg->pgdidx, vaddr);
- if (!(spgd->flags & _PAGE_PRESENT)) {
+ if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) {
/* No shadow entry: allocate a new shadow PTE page. */
unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
/* This is not really the Guest's fault, but killing it is
check_gpgd(lg, gpgd);
/* And we copy the flags to the shadow PGD entry. The page
* number in the shadow PGD is the page we just allocated. */
- spgd->raw.val = (__pa(ptepage) | gpgd.flags);
+ *spgd = __pgd(__pa(ptepage) | pgd_flags(gpgd));
}
/* OK, now we look at the lower level in the Guest page table: keep its
* address, because we might update it later. */
gpte_ptr = gpte_addr(lg, gpgd, vaddr);
- gpte = mkgpte(lgread_u32(lg, gpte_ptr));
+ gpte = __pte(lgread_u32(lg, gpte_ptr));
/* If this page isn't in the Guest page tables, we can't page it in. */
- if (!(gpte.flags & _PAGE_PRESENT))
+ if (!(pte_flags(gpte) & _PAGE_PRESENT))
return 0;
/* Check they're not trying to write to a page the Guest wants
* read-only (bit 2 of errcode == write). */
- if ((errcode & 2) && !(gpte.flags & _PAGE_RW))
+ if ((errcode & 2) && !(pte_flags(gpte) & _PAGE_RW))
return 0;
/* User access to a kernel page? (bit 3 == user access) */
- if ((errcode & 4) && !(gpte.flags & _PAGE_USER))
+ if ((errcode & 4) && !(pte_flags(gpte) & _PAGE_USER))
return 0;
/* Check that the Guest PTE flags are OK, and the page number is below
* the pfn_limit (ie. not mapping the Launcher binary). */
check_gpte(lg, gpte);
/* Add the _PAGE_ACCESSED and (for a write) _PAGE_DIRTY flag */
- gpte.flags |= _PAGE_ACCESSED;
+ gpte = pte_mkyoung(gpte);
+
if (errcode & 2)
- gpte.flags |= _PAGE_DIRTY;
+ gpte = pte_mkdirty(gpte);
/* Get the pointer to the shadow PTE entry we're going to set. */
spte = spte_addr(lg, *spgd, vaddr);
/* If this is a write, we insist that the Guest page is writable (the
* final arg to gpte_to_spte()). */
- if (gpte.flags & _PAGE_DIRTY)
+ if (pte_dirty(gpte))
*spte = gpte_to_spte(lg, gpte, 1);
- else {
+ else
/* If this is a read, don't set the "writable" bit in the page
* table entry, even if the Guest says it's writable. That way
* we come back here when a write does actually ocur, so we can
* update the Guest's _PAGE_DIRTY flag. */
- gpte_t ro_gpte = gpte;
- ro_gpte.flags &= ~_PAGE_RW;
- *spte = gpte_to_spte(lg, ro_gpte, 0);
- }
+ *spte = gpte_to_spte(lg, pte_wrprotect(gpte), 0);
/* Finally, we write the Guest PTE entry back: we've set the
* _PAGE_ACCESSED and maybe the _PAGE_DIRTY flags. */
- lgwrite_u32(lg, gpte_ptr, gpte.raw.val);
+ lgwrite_u32(lg, gpte_ptr, pte_val(gpte));
/* We succeeded in mapping the page! */
return 1;
* mapped by the shadow page tables, and is it writable? */
static int page_writable(struct lguest *lg, unsigned long vaddr)
{
- spgd_t *spgd;
+ pgd_t *spgd;
unsigned long flags;
/* Look at the top level entry: is it present? */
spgd = spgd_addr(lg, lg->pgdidx, vaddr);
- if (!(spgd->flags & _PAGE_PRESENT))
+ if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
return 0;
/* Check the flags on the pte entry itself: it must be present and
* writable. */
- flags = spte_addr(lg, *spgd, vaddr)->flags;
+ flags = pte_flags(*(spte_addr(lg, *spgd, vaddr)));
+
return (flags & (_PAGE_PRESENT|_PAGE_RW)) == (_PAGE_PRESENT|_PAGE_RW);
}
}
/*H:450 If we chase down the release_pgd() code, it looks like this: */
-static void release_pgd(struct lguest *lg, spgd_t *spgd)
+static void release_pgd(struct lguest *lg, pgd_t *spgd)
{
/* If the entry's not present, there's nothing to release. */
- if (spgd->flags & _PAGE_PRESENT) {
+ if (pgd_flags(*spgd) & _PAGE_PRESENT) {
unsigned int i;
/* Converting the pfn to find the actual PTE page is easy: turn
* the page number into a physical address, then convert to a
* virtual address (easy for kernel pages like this one). */
- spte_t *ptepage = __va(spgd->pfn << PAGE_SHIFT);
+ pte_t *ptepage = __va(pgd_pfn(*spgd) << PAGE_SHIFT);
/* For each entry in the page, we might need to release it. */
- for (i = 0; i < PTES_PER_PAGE; i++)
+ for (i = 0; i < PTRS_PER_PTE; i++)
release_pte(ptepage[i]);
/* Now we can free the page of PTEs */
free_page((long)ptepage);
/* And zero out the PGD entry we we never release it twice. */
- spgd->raw.val = 0;
+ *spgd = __pgd(0);
}
}
{
unsigned int i;
/* Release every pgd entry up to the kernel's address. */
- for (i = 0; i < vaddr_to_pgd_index(lg->page_offset); i++)
+ for (i = 0; i < pgd_index(lg->page_offset); i++)
release_pgd(lg, lg->pgdirs[idx].pgdir + i);
}
next = random32() % ARRAY_SIZE(lg->pgdirs);
/* If it's never been allocated at all before, try now. */
if (!lg->pgdirs[next].pgdir) {
- lg->pgdirs[next].pgdir = (spgd_t *)get_zeroed_page(GFP_KERNEL);
+ lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
/* If the allocation fails, just keep using the one we have */
if (!lg->pgdirs[next].pgdir)
next = lg->pgdidx;
* they set _PAGE_DIRTY then we can put a writable PTE entry in immediately.
*/
static void do_set_pte(struct lguest *lg, int idx,
- unsigned long vaddr, gpte_t gpte)
+ unsigned long vaddr, pte_t gpte)
{
/* Look up the matching shadow page directot entry. */
- spgd_t *spgd = spgd_addr(lg, idx, vaddr);
+ pgd_t *spgd = spgd_addr(lg, idx, vaddr);
/* If the top level isn't present, there's no entry to update. */
- if (spgd->flags & _PAGE_PRESENT) {
+ if (pgd_flags(*spgd) & _PAGE_PRESENT) {
/* Otherwise, we start by releasing the existing entry. */
- spte_t *spte = spte_addr(lg, *spgd, vaddr);
+ pte_t *spte = spte_addr(lg, *spgd, vaddr);
release_pte(*spte);
/* If they're setting this entry as dirty or accessed, we might
* as well put that entry they've given us in now. This shaves
* 10% off a copy-on-write micro-benchmark. */
- if (gpte.flags & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
+ if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
check_gpte(lg, gpte);
- *spte = gpte_to_spte(lg, gpte, gpte.flags&_PAGE_DIRTY);
+ *spte = gpte_to_spte(lg, gpte,
+ pte_flags(gpte) & _PAGE_DIRTY);
} else
/* Otherwise we can demand_page() it in later. */
- spte->raw.val = 0;
+ *spte = __pte(0);
}
}
* The benefit is that when we have to track a new page table, we can copy keep
* all the kernel mappings. This speeds up context switch immensely. */
void guest_set_pte(struct lguest *lg,
- unsigned long cr3, unsigned long vaddr, gpte_t gpte)
+ unsigned long cr3, unsigned long vaddr, pte_t gpte)
{
/* Kernel mappings must be changed on all top levels. Slow, but
* doesn't happen often. */
int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
{
/* In flush_user_mappings() we loop from 0 to
- * "vaddr_to_pgd_index(lg->page_offset)". This assumes it won't hit
+ * "pgd_index(lg->page_offset)". This assumes it won't hit
* the Switcher mappings, so check that now. */
- if (vaddr_to_pgd_index(lg->page_offset) >= SWITCHER_PGD_INDEX)
+ if (pgd_index(lg->page_offset) >= SWITCHER_PGD_INDEX)
return -EINVAL;
/* We start on the first shadow page table, and give it a blank PGD
* page. */
lg->pgdidx = 0;
lg->pgdirs[lg->pgdidx].cr3 = pgtable;
- lg->pgdirs[lg->pgdidx].pgdir = (spgd_t*)get_zeroed_page(GFP_KERNEL);
+ lg->pgdirs[lg->pgdidx].pgdir = (pgd_t*)get_zeroed_page(GFP_KERNEL);
if (!lg->pgdirs[lg->pgdidx].pgdir)
return -ENOMEM;
return 0;
* for each CPU already set up, we just need to hook them in. */
void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
{
- spte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
- spgd_t switcher_pgd;
- spte_t regs_pte;
+ pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
+ pgd_t switcher_pgd;
+ pte_t regs_pte;
/* Make the last PGD entry for this Guest point to the Switcher's PTE
* page for this CPU (with appropriate flags). */
- switcher_pgd.pfn = __pa(switcher_pte_page) >> PAGE_SHIFT;
- switcher_pgd.flags = _PAGE_KERNEL;
+ switcher_pgd = __pgd(__pa(switcher_pte_page) | _PAGE_KERNEL);
+
lg->pgdirs[lg->pgdidx].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd;
/* We also change the Switcher PTE page. When we're running the Guest,
* CPU's "struct lguest_pages": if we make sure the Guest's register
* page is already mapped there, we don't have to copy them out
* again. */
- regs_pte.pfn = __pa(lg->regs_page) >> PAGE_SHIFT;
- regs_pte.flags = _PAGE_KERNEL;
- switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTES_PER_PAGE]
- = regs_pte;
+ regs_pte = pfn_pte (__pa(lg->regs_page) >> PAGE_SHIFT, __pgprot(_PAGE_KERNEL));
+ switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTRS_PER_PTE] = regs_pte;
}
/*:*/
unsigned int pages)
{
unsigned int i;
- spte_t *pte = switcher_pte_page(cpu);
+ pte_t *pte = switcher_pte_page(cpu);
/* The first entries are easy: they map the Switcher code. */
for (i = 0; i < pages; i++) {
- pte[i].pfn = page_to_pfn(switcher_page[i]);
- pte[i].flags = _PAGE_PRESENT|_PAGE_ACCESSED;
+ pte[i] = mk_pte(switcher_page[i],
+ __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED));
}
/* The only other thing we map is this CPU's pair of pages. */
i = pages + cpu*2;
/* First page (Guest registers) is writable from the Guest */
- pte[i].pfn = page_to_pfn(switcher_page[i]);
- pte[i].flags = _PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW;
+ pte[i] = pfn_pte(page_to_pfn(switcher_page[i]),
+ __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW));
+
/* The second page contains the "struct lguest_ro_state", and is
* read-only. */
- pte[i+1].pfn = page_to_pfn(switcher_page[i+1]);
- pte[i+1].flags = _PAGE_PRESENT|_PAGE_ACCESSED;
+ pte[i+1] = pfn_pte(page_to_pfn(switcher_page[i+1]),
+ __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED));
}
/*H:510 At boot or module load time, init_pagetables() allocates and populates
unsigned int i;
for_each_possible_cpu(i) {
- switcher_pte_page(i) = (spte_t *)get_zeroed_page(GFP_KERNEL);
+ switcher_pte_page(i) = (pte_t *)get_zeroed_page(GFP_KERNEL);
if (!switcher_pte_page(i)) {
free_switcher_pte_pages();
return -ENOMEM;
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