![Jeremy Fitzhardinge](/assets/img/avatar_default.png)
Rather than using _PAGE_GLOBAL - which not all CPUs support - to test CPA, use one of the reserved-for-software-use PTE flags instead. This allows CPA testing to work on CPUs which don't support PGD. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
261 lines
5.2 KiB
C
261 lines
5.2 KiB
C
/*
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* self test for change_page_attr.
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*
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* Clears the a test pte bit on random pages in the direct mapping,
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* then reverts and compares page tables forwards and afterwards.
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*/
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#include <linux/bootmem.h>
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#include <linux/kthread.h>
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#include <linux/random.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <asm/cacheflush.h>
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#include <asm/pgtable.h>
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#include <asm/kdebug.h>
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/*
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* Only print the results of the first pass:
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*/
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static __read_mostly int print = 1;
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enum {
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NTEST = 400,
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#ifdef CONFIG_X86_64
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LPS = (1 << PMD_SHIFT),
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#elif defined(CONFIG_X86_PAE)
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LPS = (1 << PMD_SHIFT),
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#else
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LPS = (1 << 22),
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#endif
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GPS = (1<<30)
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};
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#define PAGE_TESTBIT __pgprot(_PAGE_UNUSED1)
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static int pte_testbit(pte_t pte)
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{
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return pte_flags(pte) & _PAGE_UNUSED1;
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}
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struct split_state {
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long lpg, gpg, spg, exec;
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long min_exec, max_exec;
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};
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static int print_split(struct split_state *s)
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{
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long i, expected, missed = 0;
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int err = 0;
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s->lpg = s->gpg = s->spg = s->exec = 0;
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s->min_exec = ~0UL;
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s->max_exec = 0;
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for (i = 0; i < max_pfn_mapped; ) {
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unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
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unsigned int level;
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pte_t *pte;
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pte = lookup_address(addr, &level);
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if (!pte) {
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missed++;
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i++;
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continue;
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}
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if (level == PG_LEVEL_1G && sizeof(long) == 8) {
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s->gpg++;
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i += GPS/PAGE_SIZE;
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} else if (level == PG_LEVEL_2M) {
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if (!(pte_val(*pte) & _PAGE_PSE)) {
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printk(KERN_ERR
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"%lx level %d but not PSE %Lx\n",
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addr, level, (u64)pte_val(*pte));
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err = 1;
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}
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s->lpg++;
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i += LPS/PAGE_SIZE;
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} else {
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s->spg++;
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i++;
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}
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if (!(pte_val(*pte) & _PAGE_NX)) {
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s->exec++;
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if (addr < s->min_exec)
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s->min_exec = addr;
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if (addr > s->max_exec)
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s->max_exec = addr;
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}
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}
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if (print) {
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printk(KERN_INFO
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" 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
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s->spg, s->lpg, s->gpg, s->exec,
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s->min_exec != ~0UL ? s->min_exec : 0,
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s->max_exec, missed);
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}
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expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
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if (expected != i) {
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printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n",
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max_pfn_mapped, expected);
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return 1;
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}
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return err;
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}
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static unsigned long addr[NTEST];
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static unsigned int len[NTEST];
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/* Change the global bit on random pages in the direct mapping */
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static int pageattr_test(void)
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{
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struct split_state sa, sb, sc;
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unsigned long *bm;
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pte_t *pte, pte0;
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int failed = 0;
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unsigned int level;
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int i, k;
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int err;
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if (print)
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printk(KERN_INFO "CPA self-test:\n");
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bm = vmalloc((max_pfn_mapped + 7) / 8);
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if (!bm) {
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printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
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return -ENOMEM;
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}
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memset(bm, 0, (max_pfn_mapped + 7) / 8);
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failed += print_split(&sa);
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srandom32(100);
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for (i = 0; i < NTEST; i++) {
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unsigned long pfn = random32() % max_pfn_mapped;
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addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
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len[i] = random32() % 100;
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len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
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if (len[i] == 0)
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len[i] = 1;
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pte = NULL;
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pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
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for (k = 0; k < len[i]; k++) {
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pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
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if (!pte || pgprot_val(pte_pgprot(*pte)) == 0 ||
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!(pte_val(*pte) & _PAGE_PRESENT)) {
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addr[i] = 0;
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break;
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}
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if (k == 0) {
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pte0 = *pte;
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} else {
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if (pgprot_val(pte_pgprot(*pte)) !=
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pgprot_val(pte_pgprot(pte0))) {
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len[i] = k;
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break;
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}
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}
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if (test_bit(pfn + k, bm)) {
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len[i] = k;
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break;
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}
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__set_bit(pfn + k, bm);
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}
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if (!addr[i] || !pte || !k) {
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addr[i] = 0;
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continue;
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}
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err = change_page_attr_set(addr[i], len[i], PAGE_TESTBIT);
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if (err < 0) {
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printk(KERN_ERR "CPA %d failed %d\n", i, err);
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failed++;
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}
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pte = lookup_address(addr[i], &level);
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if (!pte || !pte_testbit(*pte) || pte_huge(*pte)) {
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printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
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pte ? (u64)pte_val(*pte) : 0ULL);
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failed++;
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}
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if (level != PG_LEVEL_4K) {
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printk(KERN_ERR "CPA %lx: unexpected level %d\n",
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addr[i], level);
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failed++;
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}
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}
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vfree(bm);
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failed += print_split(&sb);
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for (i = 0; i < NTEST; i++) {
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if (!addr[i])
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continue;
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pte = lookup_address(addr[i], &level);
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if (!pte) {
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printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
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failed++;
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continue;
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}
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err = change_page_attr_clear(addr[i], len[i], PAGE_TESTBIT);
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if (err < 0) {
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printk(KERN_ERR "CPA reverting failed: %d\n", err);
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failed++;
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}
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pte = lookup_address(addr[i], &level);
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if (!pte || pte_testbit(*pte)) {
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printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
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addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
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failed++;
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}
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}
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failed += print_split(&sc);
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if (failed) {
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printk(KERN_ERR "NOT PASSED. Please report.\n");
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WARN_ON(1);
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return -EINVAL;
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} else {
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if (print)
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printk(KERN_INFO "ok.\n");
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}
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return 0;
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}
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static int do_pageattr_test(void *__unused)
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{
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while (!kthread_should_stop()) {
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schedule_timeout_interruptible(HZ*30);
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if (pageattr_test() < 0)
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break;
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if (print)
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print--;
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}
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return 0;
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}
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static int start_pageattr_test(void)
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{
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struct task_struct *p;
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p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
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if (!IS_ERR(p))
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wake_up_process(p);
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else
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WARN_ON(1);
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return 0;
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}
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module_init(start_pageattr_test);
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