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wpt-util.c
284 lines (240 loc) · 6.63 KB
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wpt-util.c
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/*
* File wpt-util.c
*
* LeapIO utilities for walking page table
*
* Written by Huaicheng Li <huaicheng@cs.uchicago.edu>
*/
#include "wpt.h"
//#define DEBUG_PT_WALK
#if 0
static int printbinary(char *buf, unsigned long x, int nbits)
{
u64 mask = 1UL << (nbits - 1);
while (mask != 0) {
*buf++ = (mask & x ? '1' : '0');
mask >>= 1;
}
*buf = '\0';
return nbits;
}
#endif
void get_pgt_macro(void)
{
printk("PAGE_OFFSET = 0x%lx\n", PAGE_OFFSET);
printk("PGDIR_SHIFT = %d\n", PGDIR_SHIFT);
printk("P4D_SHIFT = %d\n", P4D_SHIFT);
printk("PUD_SHIFT = %d\n", PUD_SHIFT);
printk("PMD_SHIFT = %d\n", PMD_SHIFT);
printk("PTE_SHIFT = %d\n", PAGE_SHIFT);
printk("PTRS_PER_PGD = %d\n", PTRS_PER_PGD);
printk("PTRS_PER_P4D = %d\n", PTRS_PER_P4D);
printk("PTRS_PER_PUD = %d\n", PTRS_PER_PUD);
printk("PTRS_PER_PMD = %d\n", PTRS_PER_PMD);
printk("PTRS_PER_PTE = %d\n", PTRS_PER_PTE);
printk("PAGE_MASK = 0x%lx\n", PAGE_MASK);
}
/*
* Coperd: page table walk, return the corresponding PTE
* need to call pte_unmap() later, TODO: support hugepages
*/
pte_t *va2pte(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *ptep;
pgd = pgd_offset(mm, addr);
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) {
printk("Coperd,invalid pgd [%p]\n", pgd);
goto out;
}
p4d = p4d_offset(pgd, addr);
if (p4d_none(*p4d) || unlikely(p4d_bad(*p4d))) {
printk("Coperd, invalid p4d [%p]", p4d);
goto out;
}
pud = pud_offset(p4d, addr);
if (pud_none(*pud) || unlikely(pud_bad(*pud))) {
printk("Coperd, invalid pud [%p]", pud);
goto out;
}
pmd = pmd_offset(pud, addr);
/* Coperd: TODO: sometimes pmd_bad() is true */
if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) {
printk("Coperd, invalid pmd [%p]", pmd);
goto out;
}
ptep = pte_offset_map(pmd, addr);
//ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
if (!ptep) {
printk("Coperd,%d,pt_offset_map() failed\n", __LINE__);
goto out;
}
return ptep;
out:
return NULL;
}
static int pud_huge(pud_t pud)
{
return !!(pud_val(pud) & _PAGE_PSE);
}
static int pmd_huge(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_PSE);
}
/* Coperd: hva2hpa translation, with hugepage support */
u64 hva2hpa(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *ptep;
u64 hpa = 0;
unsigned long offset;
pgd = pgd_offset(mm, addr);
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) {
pr_err("Coperd,invalid PGD [%lx]\n", pgd_val(*pgd));
goto out;
}
p4d = p4d_offset(pgd, addr);
if (p4d_none(*p4d) || unlikely(p4d_bad(*p4d))) {
pr_err("Coperd, invalid P4D [%lx]", p4d_val(*p4d));
goto out;
}
pud = pud_offset(p4d, addr);
if (pud_none(*pud) || !pud_present(*pud)) {
pr_err("Coperd, invalid PUD [%lx]", pud_val(*pud));
goto out;
}
/* Coperd: 1GB hugepage */
if (pud_huge(*pud)) {
hpa = pud_pfn(*pud) << PAGE_SHIFT;
offset = addr & ~PUD_PAGE_MASK;
#ifdef DEBUG_PT_WALK
printk("Coperd,1GB huagepage,0x%llx\n", hpa);
#endif
return (hpa | offset);
}
if (unlikely(pud_bad(*pud))) {
pr_err("Coperd,bad PUD [%lx]\n", pud_val(*pud));
goto out;
}
pmd = pmd_offset(pud, addr);
/* Coperd: TODO: sometimes pmd_bad() is true */
if (pmd_none(*pmd) || !pmd_present(*pmd)) {
pr_err("Coperd, invalid PMD [%lx]", pmd_val(*pmd));
goto out;
}
/* Coperd: 2MB hugepage */
if (pmd_huge(*pmd)) {
hpa = pmd_pfn(*pmd) << PAGE_SHIFT;
offset = addr & ~PMD_PAGE_MASK;
#ifdef DEBUG_PT_WALK
printk("Coperd,2MB huagepage,0x%llx\n", hpa);
#endif
return (hpa | offset);
}
if (unlikely(pmd_bad(*pmd))) {
pr_err("Coperd, bad PMD [%lx]", pmd_val(*pmd));
goto out;
}
ptep = pte_offset_map(pmd, addr);
//ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
if (!ptep) {
pr_err("Coperd,%d,pt_offset_map() failed\n", __LINE__);
goto out;
}
hpa = pte_pfn(*ptep) << PAGE_SHIFT;
pte_unmap(ptep);
#ifdef DEBUG_PT_WALK
printk("Coperd,4KB page,0x%llx\n", hpa);
#endif
offset = addr & ~PAGE_MASK;
return (hpa | offset);
out:
return WPT_INVALID_PFN;
}
struct kvm *get_kvm(pid_t vm_pid)
{
struct kvm *kvm;
list_for_each_entry(kvm, &vm_list, vm_list) {
if (kvm->userspace_pid == vm_pid) {
printk("===> pid[%d]: kvm[%lx]\n", vm_pid, (unsigned long)kvm);
return kvm;
}
}
return NULL;
}
/*
* Some mappings aren't backed by a struct page, for example an mmap'd
* MMIO range for our own or another device. These use a different
* pfn conversion and shouldn't be tracked as locked pages.
*/
static bool is_invalid_reserved_pfn(unsigned long pfn)
{
if (pfn_valid(pfn)) {
bool reserved;
struct page *tail = pfn_to_page(pfn);
struct page *head = compound_head(tail);
reserved = !!(PageReserved(head));
if (head != tail) {
/*
* "head" is not a dangling pointer
* (compound_head takes care of that)
* but the hugepage may have been split
* from under us (and we may not hold a
* reference count on the head page so it can
* be reused before we run PageReferenced), so
* we've to check PageTail before returning
* what we just read.
*/
smp_rmb();
if (PageTail(tail))
return reserved;
}
return PageReserved(tail);
}
return true;
}
int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, unsigned long *pfn)
{
struct page *page[1];
//struct vm_area_struct *vma;
int ret;
if (mm == current->mm) {
ret = get_user_pages_fast(vaddr, 1, 0, page);
} else {
down_read(&mm->mmap_sem);
ret = get_user_pages_remote(NULL, mm, vaddr, 1, 0, page, NULL, NULL);
up_read(&mm->mmap_sem);
}
if (ret == 1) {
*pfn = page_to_pfn(page[0]);
return 0;
}
pr_err("%s,vaddr[%lx] translation failed\n", __func__, vaddr);
return -1;
#if 0
down_read(&mm->mmap_sem);
vma = find_vma_intersection(mm, vaddr, vaddr + 1);
if (vma && vma->vm_flags & VM_PFNMAP) {
*pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
if (is_invalid_reserved_pfn(*pfn))
ret = 0;
}
up_read(&mm->mmap_sem);
return ret;
#endif
}
int put_pfn(unsigned long pfn)
{
if (!is_invalid_reserved_pfn(pfn)) {
struct page *page = pfn_to_page(pfn);
put_page(page);
return 1;
}
return 0;
}