static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
unsigned long end, unsigned long pfn,
pgprot_t prot)
{
pud_t *pud;
pmd_t *pmd;
unsigned long addr, next;
int ret;
addr = start;
do {
pud = pud_offset(pgd, addr);
if (pud_none_or_clear_bad(pud)) {
pmd = pmd_alloc_one(NULL, addr);
if (!pmd) {
kvm_err("Cannot allocate Hyp pmd\n");
return -ENOMEM;
}
pud_populate(NULL, pud, pmd);
get_page(virt_to_page(pud));
kvm_flush_dcache_to_poc(pud, sizeof(*pud));
}
next = pud_addr_end(addr, end);
ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
if (ret)
return ret;
pfn += (next - addr) >> PAGE_SHIFT;
} while (addr = next, addr != end);
return 0;
}
static void __init kasan_populate_pud(pud_t *pud, unsigned long addr,
unsigned long end, int nid)
{
pmd_t *pmd;
unsigned long next;
if (pud_none(*pud)) {
void *p;
if (boot_cpu_has(X86_FEATURE_GBPAGES) &&
((end - addr) == PUD_SIZE) &&
IS_ALIGNED(addr, PUD_SIZE)) {
p = early_alloc(PUD_SIZE, nid, false);
if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL))
return;
else if (p)
memblock_free(__pa(p), PUD_SIZE);
}
p = early_alloc(PAGE_SIZE, nid, true);
pud_populate(&init_mm, pud, p);
}
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (!pmd_large(*pmd))
kasan_populate_pmd(pmd, addr, next, nid);
} while (pmd++, addr = next, addr != end);
}
/**
* kvm_mips_walk_pgd() - Walk page table with optional allocation.
* @pgd: Page directory pointer.
* @addr: Address to index page table using.
* @cache: MMU page cache to allocate new page tables from, or NULL.
*
* Walk the page tables pointed to by @pgd to find the PTE corresponding to the
* address @addr. If page tables don't exist for @addr, they will be created
* from the MMU cache if @cache is not NULL.
*
* Returns: Pointer to pte_t corresponding to @addr.
* NULL if a page table doesn't exist for @addr and !@cache.
* NULL if a page table allocation failed.
*/
static pte_t *kvm_mips_walk_pgd(pgd_t *pgd, struct kvm_mmu_memory_cache *cache,
unsigned long addr)
{
pud_t *pud;
pmd_t *pmd;
pgd += pgd_index(addr);
if (pgd_none(*pgd)) {
/* Not used on MIPS yet */
BUG();
return NULL;
}
pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
pmd_t *new_pmd;
if (!cache)
return NULL;
new_pmd = mmu_memory_cache_alloc(cache);
pmd_init((unsigned long)new_pmd,
(unsigned long)invalid_pte_table);
pud_populate(NULL, pud, new_pmd);
}
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
pte_t *new_pte;
if (!cache)
return NULL;
new_pte = mmu_memory_cache_alloc(cache);
clear_page(new_pte);
pmd_populate_kernel(NULL, pmd, new_pte);
}
return pte_offset(pmd, addr);
}
static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
unsigned long prot)
{
pmd_t *pmd;
unsigned long next;
if (pud_none_or_clear_bad(pud) || (pud_val(*pud) & L_PGD_SWAPPER)) {
pmd = pmd_alloc_one(&init_mm, addr);
if (!pmd) {
pr_warning("Failed to allocate identity pmd.\n");
return;
}
/*
* Copy the original PMD to ensure that the PMD entries for
* the kernel image are preserved.
*/
if (!pud_none(*pud))
memcpy(pmd, pmd_offset(pud, 0),
PTRS_PER_PMD * sizeof(pmd_t));
pud_populate(&init_mm, pud, pmd);
pmd += pmd_index(addr);
} else
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
*pmd = __pmd((addr & PMD_MASK) | prot);
flush_pmd_entry(pmd);
} while (pmd++, addr = next, addr != end);
}
static int copy_pmd(pud_t *dst_pudp, pud_t *src_pudp, unsigned long start,
unsigned long end)
{
pmd_t *src_pmdp;
pmd_t *dst_pmdp;
unsigned long next;
unsigned long addr = start;
if (pud_none(READ_ONCE(*dst_pudp))) {
dst_pmdp = (pmd_t *)get_safe_page(GFP_ATOMIC);
if (!dst_pmdp)
return -ENOMEM;
pud_populate(&init_mm, dst_pudp, dst_pmdp);
}
dst_pmdp = pmd_offset(dst_pudp, start);
src_pmdp = pmd_offset(src_pudp, start);
do {
pmd_t pmd = READ_ONCE(*src_pmdp);
next = pmd_addr_end(addr, end);
if (pmd_none(pmd))
continue;
if (pmd_table(pmd)) {
if (copy_pte(dst_pmdp, src_pmdp, addr, next))
return -ENOMEM;
} else {
set_pmd(dst_pmdp,
__pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY));
}
} while (dst_pmdp++, src_pmdp++, addr = next, addr != end);
return 0;
}
static pmd_t * __init one_md_table_init(pud_t *pud)
{
if (pud_none(*pud)) {
pmd_t *pmd;
pmd = alloc_bootmem_pages(PAGE_SIZE);
pud_populate(&init_mm, pud, pmd);
BUG_ON(pmd != pmd_offset(pud, 0));
}
return pmd_offset(pud, 0);
}
static void alloc_init_pmd(struct mm_struct *mm, pud_t *pud,
unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
void *(*alloc)(unsigned long size))
{
pmd_t *pmd;
unsigned long next;
/*
* Check for initial section mappings in the pgd/pud and remove them.
*/
if (pud_none(*pud) || pud_sect(*pud)) {
pmd = alloc(PTRS_PER_PMD * sizeof(pmd_t));
if (pud_sect(*pud)) {
/*
* need to have the 1G of mappings continue to be
* present
*/
split_pud(pud, pmd);
}
pud_populate(mm, pud, pmd);
flush_tlb_all();
}
BUG_ON(pud_bad(*pud));
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
/* try section mapping first */
if (((addr | next | phys) & ~SECTION_MASK) == 0) {
pmd_t old_pmd =*pmd;
set_pmd(pmd, __pmd(phys |
pgprot_val(mk_sect_prot(prot))));
/*
* Check for previous table entries created during
* boot (__create_page_tables) and flush them.
*/
if (!pmd_none(old_pmd)) {
flush_tlb_all();
if (pmd_table(old_pmd)) {
phys_addr_t table = __pa(pte_offset_map(&old_pmd, 0));
if (!WARN_ON_ONCE(slab_is_available()))
memblock_free(table, PAGE_SIZE);
}
}
} else {
alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
prot, alloc);
}
phys += next - addr;
} while (pmd++, addr = next, addr != end);
}
static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
unsigned long end)
{
pud_t *pud = pud_offset(pgd, addr);
unsigned long next;
do {
next = pud_addr_end(addr, end);
if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) {
pmd_t *pmd;
pud_populate(&init_mm, pud, kasan_zero_pmd);
pmd = pmd_offset(pud, addr);
pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
continue;
}
if (pud_none(*pud)) {
pud_populate(&init_mm, pud,
early_alloc(PAGE_SIZE, NUMA_NO_NODE));
}
zero_pmd_populate(pud, addr, next);
} while (pud++, addr = next, addr != end);
}
static void __init kasan_early_pmd_populate(pud_t *pud,
unsigned long addr,
unsigned long end)
{
pmd_t *pmd;
unsigned long next;
if (pud_none(*pud))
pud_populate(&init_mm, pud, kasan_zero_pmd);
pmd = pmd_offset_kimg(pud, addr);
do {
next = pmd_addr_end(addr, end);
kasan_early_pte_populate(pmd, addr, next);
} while (pmd++, addr = next, addr != end && pmd_none(*pmd));
}
static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
phys_addr_t addr, const pte_t *new_pte, bool iomap)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte, old_pte;
/* Create 2nd stage page table mapping - Level 1 */
pgd = kvm->arch.pgd + pgd_index(addr);
pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
if (!cache)
return 0; /* ignore calls from kvm_set_spte_hva */
pmd = mmu_memory_cache_alloc(cache);
pud_populate(NULL, pud, pmd);
get_page(virt_to_page(pud));
}
pmd = pmd_offset(pud, addr);
/* Create 2nd stage page table mapping - Level 2 */
if (pmd_none(*pmd)) {
if (!cache)
return 0; /* ignore calls from kvm_set_spte_hva */
pte = mmu_memory_cache_alloc(cache);
kvm_clean_pte(pte);
pmd_populate_kernel(NULL, pmd, pte);
get_page(virt_to_page(pmd));
}
pte = pte_offset_kernel(pmd, addr);
if (iomap && pte_present(*pte))
return -EFAULT;
/* Create 2nd stage page table mapping - Level 3 */
old_pte = *pte;
kvm_set_pte(pte, *new_pte);
if (pte_present(old_pte))
kvm_tlb_flush_vmid_ipa(kvm, addr);
else
get_page(virt_to_page(pte));
return 0;
}
static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
phys_addr_t addr)
{
pud_t *pud;
pmd_t *pmd;
pud = stage2_get_pud(kvm, cache, addr);
if (pud_none(*pud)) {
if (!cache)
return NULL;
pmd = mmu_memory_cache_alloc(cache);
pud_populate(NULL, pud, pmd);
get_page(virt_to_page(pud));
}
return pmd_offset(pud, addr);
}
static int early_map_kernel_page(unsigned long ea, unsigned long pa,
pgprot_t flags,
unsigned int map_page_size,
int nid,
unsigned long region_start, unsigned long region_end)
{
unsigned long pfn = pa >> PAGE_SHIFT;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pgdp = pgd_offset_k(ea);
if (pgd_none(*pgdp)) {
pudp = early_alloc_pgtable(PUD_TABLE_SIZE, nid,
region_start, region_end);
pgd_populate(&init_mm, pgdp, pudp);
}
pudp = pud_offset(pgdp, ea);
if (map_page_size == PUD_SIZE) {
ptep = (pte_t *)pudp;
goto set_the_pte;
}
if (pud_none(*pudp)) {
pmdp = early_alloc_pgtable(PMD_TABLE_SIZE, nid,
region_start, region_end);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (map_page_size == PMD_SIZE) {
ptep = pmdp_ptep(pmdp);
goto set_the_pte;
}
if (!pmd_present(*pmdp)) {
ptep = early_alloc_pgtable(PAGE_SIZE, nid,
region_start, region_end);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
set_the_pte:
set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
smp_wmb();
return 0;
}
/*
* map_kernel_page currently only called by __ioremap
* map_kernel_page adds an entry to the ioremap page table
* and adds an entry to the HPT, possibly bolting it
*/
int __ref map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
if (slab_is_available()) {
pgdp = pgd_offset_k(ea);
pudp = pud_alloc(&init_mm, pgdp, ea);
if (!pudp)
return -ENOMEM;
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
} else {
pgdp = pgd_offset_k(ea);
#ifndef __PAGETABLE_PUD_FOLDED
if (pgd_none(*pgdp)) {
pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
pgd_populate(&init_mm, pgdp, pudp);
}
#endif /* !__PAGETABLE_PUD_FOLDED */
pudp = pud_offset(pgdp, ea);
if (pud_none(*pudp)) {
pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (!pmd_present(*pmdp)) {
ptep = early_alloc_pgtable(PAGE_SIZE);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
}
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
smp_wmb();
return 0;
}
static int __create_hyp_mappings(pgd_t *pgdp,
unsigned long start, unsigned long end,
unsigned long pfn, pgprot_t prot)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
unsigned long addr, next;
int err = 0;
mutex_lock(&kvm_hyp_pgd_mutex);
addr = start & PAGE_MASK;
end = PAGE_ALIGN(end);
do {
pgd = pgdp + pgd_index(addr);
pud = pud_offset(pgd, addr);
if (pud_none_or_clear_bad(pud)) {
pmd = pmd_alloc_one(NULL, addr);
if (!pmd) {
kvm_err("Cannot allocate Hyp pmd\n");
err = -ENOMEM;
goto out;
}
pud_populate(NULL, pud, pmd);
get_page(virt_to_page(pud));
kvm_flush_dcache_to_poc(pud, sizeof(*pud));
}
next = pgd_addr_end(addr, end);
err = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
if (err)
goto out;
pfn += (next - addr) >> PAGE_SHIFT;
} while (addr = next, addr != end);
out:
mutex_unlock(&kvm_hyp_pgd_mutex);
return err;
}
/**
* kasan_populate_zero_shadow - populate shadow memory region with
* kasan_zero_page
* @shadow_start - start of the memory range to populate
* @shadow_end - end of the memory range to populate
*/
void __init kasan_populate_zero_shadow(const void *shadow_start,
const void *shadow_end)
{
unsigned long addr = (unsigned long)shadow_start;
unsigned long end = (unsigned long)shadow_end;
pgd_t *pgd = pgd_offset_k(addr);
unsigned long next;
do {
next = pgd_addr_end(addr, end);
if (IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) {
pud_t *pud;
pmd_t *pmd;
/*
* kasan_zero_pud should be populated with pmds
* at this moment.
* [pud,pmd]_populate*() below needed only for
* 3,2 - level page tables where we don't have
* puds,pmds, so pgd_populate(), pud_populate()
* is noops.
*/
pgd_populate(&init_mm, pgd, kasan_zero_pud);
pud = pud_offset(pgd, addr);
pud_populate(&init_mm, pud, kasan_zero_pmd);
pmd = pmd_offset(pud, addr);
pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
continue;
}
if (pgd_none(*pgd)) {
pgd_populate(&init_mm, pgd,
early_alloc(PAGE_SIZE, NUMA_NO_NODE));
}
zero_pud_populate(pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}
static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
unsigned long prot)
{
pmd_t *pmd;
unsigned long next;
if (pud_none_or_clear_bad(pud) || (pud_val(*pud) & L_PGD_SWAPPER)) {
pmd = pmd_alloc_one(NULL, addr);
if (!pmd) {
pr_warning("Failed to allocate identity pmd.\n");
return;
}
pud_populate(NULL, pud, pmd);
pmd += pmd_index(addr);
} else
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
*pmd = __pmd((addr & PMD_MASK) | prot);
flush_pmd_entry(pmd);
} while (pmd++, addr = next, addr != end);
}
/**
* kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
* @kvm: The KVM struct pointer for the VM.
*
* Allocates the 1st level table only of size defined by S2_PGD_ORDER (can
* support either full 40-bit input addresses or limited to 32-bit input
* addresses). Clears the allocated pages.
*
* Note we don't need locking here as this is only called when the VM is
* created, which can only be done once.
*/
int kvm_alloc_stage2_pgd(struct kvm *kvm)
{
pgd_t *pgd;
void *hwpgd;
if (kvm->arch.pgd != NULL) {
kvm_err("kvm_arch already initialized?\n");
return -EINVAL;
}
hwpgd = kvm_alloc_hwpgd();
if (!hwpgd)
return -ENOMEM;
/* When the kernel uses more levels of page tables than the
* guest, we allocate a fake PGD and pre-populate it to point
* to the next-level page table, which will be the real
* initial page table pointed to by the VTTBR.
*
* When KVM_PREALLOC_LEVEL==2, we allocate a single page for
* the PMD and the kernel will use folded pud.
* When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD
* pages.
*/
if (KVM_PREALLOC_LEVEL > 0) {
int i;
/*
* Allocate fake pgd for the page table manipulation macros to
* work. This is not used by the hardware and we have no
* alignment requirement for this allocation.
*/
pgd = (pgd_t *)kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t),
GFP_KERNEL | __GFP_ZERO);
if (!pgd) {
kvm_free_hwpgd(hwpgd);
return -ENOMEM;
}
/* Plug the HW PGD into the fake one. */
for (i = 0; i < PTRS_PER_S2_PGD; i++) {
if (KVM_PREALLOC_LEVEL == 1)
pgd_populate(NULL, pgd + i,
(pud_t *)hwpgd + i * PTRS_PER_PUD);
else if (KVM_PREALLOC_LEVEL == 2)
pud_populate(NULL, pud_offset(pgd, 0) + i,
(pmd_t *)hwpgd + i * PTRS_PER_PMD);
}
} else {
/*
* Allocate actual first-level Stage-2 page table used by the
* hardware for Stage-2 page table walks.
*/
pgd = (pgd_t *)hwpgd;
}
kvm_clean_pgd(pgd);
kvm->arch.pgd = pgd;
return 0;
}
/*
* Copies length bytes, starting at src_start into an new page,
* perform cache maintentance, then maps it at the specified address low
* address as executable.
*
* This is used by hibernate to copy the code it needs to execute when
* overwriting the kernel text. This function generates a new set of page
* tables, which it loads into ttbr0.
*
* Length is provided as we probably only want 4K of data, even on a 64K
* page system.
*/
static int create_safe_exec_page(void *src_start, size_t length,
unsigned long dst_addr,
phys_addr_t *phys_dst_addr,
void *(*allocator)(gfp_t mask),
gfp_t mask)
{
int rc = 0;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
unsigned long dst = (unsigned long)allocator(mask);
if (!dst) {
rc = -ENOMEM;
goto out;
}
memcpy((void *)dst, src_start, length);
flush_icache_range(dst, dst + length);
pgdp = pgd_offset_raw(allocator(mask), dst_addr);
if (pgd_none(READ_ONCE(*pgdp))) {
pudp = allocator(mask);
if (!pudp) {
rc = -ENOMEM;
goto out;
}
pgd_populate(&init_mm, pgdp, pudp);
}
pudp = pud_offset(pgdp, dst_addr);
if (pud_none(READ_ONCE(*pudp))) {
pmdp = allocator(mask);
if (!pmdp) {
rc = -ENOMEM;
goto out;
}
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, dst_addr);
if (pmd_none(READ_ONCE(*pmdp))) {
ptep = allocator(mask);
if (!ptep) {
rc = -ENOMEM;
goto out;
}
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, dst_addr);
set_pte(ptep, pfn_pte(virt_to_pfn(dst), PAGE_KERNEL_EXEC));
/*
* Load our new page tables. A strict BBM approach requires that we
* ensure that TLBs are free of any entries that may overlap with the
* global mappings we are about to install.
*
* For a real hibernate/resume cycle TTBR0 currently points to a zero
* page, but TLBs may contain stale ASID-tagged entries (e.g. for EFI
* runtime services), while for a userspace-driven test_resume cycle it
* points to userspace page tables (and we must point it at a zero page
* ourselves). Elsewhere we only (un)install the idmap with preemption
* disabled, so T0SZ should be as required regardless.
*/
cpu_set_reserved_ttbr0();
local_flush_tlb_all();
write_sysreg(phys_to_ttbr(virt_to_phys(pgdp)), ttbr0_el1);
isb();
*phys_dst_addr = virt_to_phys((void *)dst);
out:
return rc;
}
