// SPDX-License-Identifier: GPL-2.0
/*
* AArch64 code
*
* Copyright (C) 2018, Red Hat, Inc.
*/
#include <linux/compiler.h>
#include <assert.h>
#include "guest_modes.h"
#include "kvm_util.h"
#include "processor.h"
#include "ucall_common.h"
#include <linux/bitfield.h>
#include <linux/sizes.h>
#define DEFAULT_ARM64_GUEST_STACK_VADDR_MIN 0xac0000
static vm_vaddr_t exception_handlers;
static uint64_t page_align(struct kvm_vm *vm, uint64_t v)
{
return (v + vm->page_size) & ~(vm->page_size - 1);
}
static uint64_t pgd_index(struct kvm_vm *vm, vm_vaddr_t gva)
{
unsigned int shift = (vm->pgtable_levels - 1) * (vm->page_shift - 3) + vm->page_shift;
uint64_t mask = (1UL << (vm->va_bits - shift)) - 1;
return (gva >> shift) & mask;
}
static uint64_t pud_index(struct kvm_vm *vm, vm_vaddr_t gva)
{
unsigned int shift = 2 * (vm->page_shift - 3) + vm->page_shift;
uint64_t mask = (1UL << (vm->page_shift - 3)) - 1;
TEST_ASSERT(vm->pgtable_levels == 4,
"Mode %d does not have 4 page table levels", vm->mode);
return (gva >> shift) & mask;
}
static uint64_t pmd_index(struct kvm_vm *vm, vm_vaddr_t gva)
{
unsigned int shift = (vm->page_shift - 3) + vm->page_shift;
uint64_t mask = (1UL << (vm->page_shift - 3)) - 1;
TEST_ASSERT(vm->pgtable_levels >= 3,
"Mode %d does not have >= 3 page table levels", vm->mode);
return (gva >> shift) & mask;
}
static uint64_t pte_index(struct kvm_vm *vm, vm_vaddr_t gva)
{
uint64_t mask = (1UL << (vm->page_shift - 3)) - 1;
return (gva >> vm->page_shift) & mask;
}
static inline bool use_lpa2_pte_format(struct kvm_vm *vm)
{
return (vm->page_size == SZ_4K || vm->page_size == SZ_16K) &&
(vm->pa_bits > 48 || vm->va_bits > 48);
}
static uint64_t addr_pte(struct kvm_vm *vm, uint64_t pa, uint64_t attrs)
{
uint64_t pte;
if (use_lpa2_pte_format(vm)) {
pte = pa & GENMASK(49, vm->page_shift);
pte |= FIELD_GET(GENMASK(51, 50), pa) << 8;
attrs &= ~GENMASK(9, 8);
} else {
pte = pa & GENMASK(47, vm->page_shift);
if (vm->page_shift == 16)
pte |= FIELD_GET(GENMASK(51, 48), pa) << 12;
}
pte |= attrs;
return pte;
}
static uint64_t pte_addr(struct kvm_vm *vm, uint64_t pte)
{
uint64_t pa;
if (use_lpa2_pte_format(vm)) {
pa = pte & GENMASK(49, vm->page_shift);
pa |= FIELD_GET(GENMASK(9, 8), pte) << 50;
} else {
pa = pte & GENMASK(47, vm->page_shift);
if (vm->page_shift == 16)
pa |= FIELD_GET(GENMASK(15, 12), pte) << 48;
}
return pa;
}
static uint64_t ptrs_per_pgd(struct kvm_vm *vm)
{
unsigned int shift = (vm->pgtable_levels - 1) * (vm->page_shift - 3) + vm->page_shift;
return 1 << (vm->va_bits - shift);
}
static uint64_t __maybe_unused ptrs_per_pte(struct kvm_vm *vm)
{
return 1 << (vm->page_shift - 3);
}
void virt_arch_pgd_alloc(struct kvm_vm *vm)
{
size_t nr_pages = page_align(vm, ptrs_per_pgd(vm) * 8) / vm->page_size;
if (vm->pgd_created)
return;
vm->pgd = vm_phy_pages_alloc(vm, nr_pages,
KVM_GUEST_PAGE_TABLE_MIN_PADDR,
vm->memslots[MEM_REGION_PT]);
vm->pgd_created = true;
}
static void _virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
uint64_t flags)
{
uint8_t attr_idx = flags & 7;
uint64_t *ptep;
TEST_ASSERT((vaddr % vm->page_size) == 0,
"Virtual address not on page boundary,\n"
" vaddr: 0x%lx vm->page_size: 0x%x", vaddr, vm->page_size);
TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
(vaddr >> vm->page_shift)),
"Invalid virtual address, vaddr: 0x%lx", vaddr);
TEST_ASSERT((paddr % vm->page_size) == 0,
"Physical address not on page boundary,\n"
" paddr: 0x%lx vm->page_size: 0x%x", paddr, vm->page_size);
TEST_ASSERT((paddr >> vm->page_shift) <= vm->max_gfn,
"Physical address beyond beyond maximum supported,\n"
" paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x",
paddr, vm->max_gfn, vm->page_size);
ptep = addr_gpa2hva(vm, vm->pgd) + pgd_index(vm, vaddr) * 8;
if (!*ptep)
*ptep = addr_pte(vm, vm_alloc_page_table(vm), 3);
switch (vm->pgtable_levels) {
case 4:
ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pud_index(vm, vaddr) * 8;
if (!*ptep)
*ptep = addr_pte(vm, vm_alloc_page_table(vm), 3);
/* fall through */
case 3:
ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pmd_index(vm, vaddr) * 8;
if (!*ptep)
*ptep = addr_pte(vm, vm_alloc_page_table(vm), 3);
/* fall through */
case 2:
ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, vaddr) * 8;
break;
default:
TEST_FAIL("Page table levels must be 2, 3, or 4");
}
*ptep = addr_pte(vm, paddr, (attr_idx << 2) | (1 << 10) | 3); /* AF */
}
void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
{
uint64_t attr_idx = MT_NORMAL;
_virt_pg_map(vm, vaddr, paddr, attr_idx);
}
uint64_t *virt_get_pte_hva(struct kvm_vm *vm, vm_vaddr_t gva)
{
uint64_t *ptep;
if (!vm->pgd_created)
goto unmapped_gva;
ptep = addr_gpa2hva(vm, vm->pgd) + pgd_index(vm, gva) * 8;
if (!ptep)
goto unmapped_gva;
switch (vm->pgtable_levels) {
case 4:
ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pud_index(vm, gva) * 8;
if (!ptep)
goto unmapped_gva;
/* fall through */
case 3:
ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pmd_index(vm, gva) * 8;
if (!ptep)
goto unmapped_gva;
/* fall through */
case 2:
ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
if (!ptep)
goto unmapped_gva;
break;
default:
TEST_FAIL("Page table levels must be 2, 3, or 4");
}
return ptep;
unmapped_gva:
TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
exit(EXIT_FAILURE);
}
vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
{
uint64_t *ptep = virt_get_pte_hva(vm, gva);
return pte_addr(vm, *ptep) + (gva & (vm->page_size - 1));
}
static void pte_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent, uint64_t page, int level)
{
#ifdef DEBUG
static const char * const type[] = { "", "pud", "pmd", "pte" };
uint64_t pte, *ptep;
if (level == 4)
return;
for (pte = page; pte < page + ptrs_per_pte(vm) * 8; pte += 8) {
ptep = addr_gpa2hva(vm, pte);
if (!*ptep)
continue;
fprintf(stream, "%*s%s: %lx: %lx at %p\n", indent, "", type[level], pte, *ptep, ptep);
pte_dump(stream, vm, indent + 1, pte_addr(vm, *ptep), level + 1);
}
#endif
}
void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
{
int level = 4 - (vm->pgtable_levels - 1);
uint64_t pgd, *ptep;
if (!vm->pgd_created)
return;
for (pgd = vm->pgd; pgd < vm->pgd + ptrs_per_pgd(vm) * 8; pgd += 8) {
ptep = addr_gpa2hva(vm, pgd);
if (!*ptep)
continue;
fprintf(stream, "%*spgd: %lx: %lx at %p\n", indent, "", pgd, *ptep, ptep);
pte_dump(stream, vm, indent + 1, pte_addr(vm, *ptep), level);
}
}
void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
{
struct kvm_vcpu_init default_init = { .target = -1, };
struct kvm_vm *vm = vcpu->vm;
uint64_t sctlr_el1, tcr_el1, ttbr0_el1;
if (!init)
init = &default_init;
if (init->target == -1) {
struct kvm_vcpu_init preferred;
vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &preferred);
init->target = preferred.target;
}
vcpu_ioctl(vcpu, KVM_ARM_VCPU_INIT, init);
/*
* Enable FP/ASIMD to avoid trapping when accessing Q0-Q15
* registers, which the variable argument list macros do.
*/
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CPACR_EL1), 3 << 20);
vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1), &sctlr_el1);
vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL1), &tcr_el1);
/* Configure base granule size */
switch (vm->mode) {
case VM_MODE_PXXV48_4K:
TEST_FAIL("AArch64 does not support 4K sized pages "
"with ANY-bit physical address ranges");
case VM_MODE_P52V48_64K:
case VM_MODE_P48V48_64K:
case VM_MODE_P40V48_64K:
case VM_MODE_P36V48_64K:
tcr_el1 |= 1ul << 14; /* TG0 = 64KB */
break;
case VM_MODE_P52V48_16K:
case VM_MODE_P48V48_16K:
case VM_MODE_P40V48_16K:
case VM_MODE_P36V48_16K:
case VM_MODE_P36V47_16K:
tcr_el1 |= 2ul << 14; /* TG0 = 16KB */
break;
case VM_MODE_P52V48_4K:
case VM_MODE_P48V48_4K:
case VM_MODE_P40V48_4K:
case VM_MODE_P36V48_4K:
tcr_el1 |= 0ul << 14; /* TG0 = 4KB */
break;
default:
TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
}
ttbr0_el1 = vm->pgd & GENMASK(47, vm->page_shift);
/* Configure output size */
switch (vm->mode) {
case VM_MODE_P52V48_4K:
case VM_MODE_P52V48_16K:
case VM_MODE_P52V48_64K:
tcr_el1 |= 6ul << 32; /* IPS = 52 bits */
ttbr0_el1 |= FIELD_GET(GENMASK(51, 48), vm->pgd) << 2;
break;
case VM_MODE_P48V48_4K:
case VM_MODE_P48V48_16K:
case VM_MODE_P48V48_64K:
tcr_el1 |= 5ul << 32; /* IPS = 48 bits */
break;
case VM_MODE_P40V48_4K:
case VM_MODE_P40V48_16K:
case VM_MODE_P40V48_64K:
tcr_el1 |= 2ul << 32; /* IPS = 40 bits */
break;
case VM_MODE_P36V48_4K:
case VM_MODE_P36V48_16K:
case VM_MODE_P36V48_64K:
case VM_MODE_P36V47_16K:
tcr_el1 |= 1ul << 32; /* IPS = 36 bits */
break;
default:
TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
}
sctlr_el1 |= (1 << 0) | (1 << 2) | (1 << 12) /* M | C | I */;
/* TCR_EL1 |= IRGN0:WBWA | ORGN0:WBWA | SH0:Inner-Shareable */;
tcr_el1 |= (1 << 8) | (1 << 10) | (3 << 12);
tcr_el1 |= (64 - vm->va_bits) /* T0SZ */;
if (use_lpa2_pte_format(vm))
tcr_el1 |= (1ul << 59) /* DS */;
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1), sctlr_el1);
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL1), tcr_el1);
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MAIR_EL1), DEFAULT_MAIR_EL1);
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TTBR0_EL1), ttbr0_el1);
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TPIDR_EL1), vcpu->id);
}
void vcpu_arch_dump(FILE *stream, struct kvm_vcpu *vcpu, uint8_t indent)
{
uint64_t pstate, pc;
vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pstate), &pstate);
vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pc), &pc);
fprintf(stream, "%*spstate: 0x%.16lx pc: 0x%.16lx\n",
indent, "", pstate, pc);
}
void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
{
vcpu_set_reg(vcpu, ARM64_CORE_REG(regs.pc), (uint64_t)guest_code);
}
static struct kvm_vcpu *__aarch64_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
struct kvm_vcpu_init *init)
{
size_t stack_size;
uint64_t stack_vaddr;
struct kvm_vcpu *vcpu = __vm_vcpu_add(vm, vcpu_id);
stack_size = vm->page_size == 4096 ? DEFAULT_STACK_PGS * vm->page_size :
vm->page_size;
stack_vaddr = __vm_vaddr_alloc(vm, stack_size,
DEFAULT_ARM64_GUEST_STACK_VADDR_MIN,
MEM_REGION_DATA);
aarch64_vcpu_setup(vcpu, init);
vcpu_set_reg(vcpu, ARM64_CORE_REG(sp_el1), stack_vaddr + stack_size);
return vcpu;
}
struct kvm_vcpu *aarch64_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
struct kvm_vcpu_init *init, void *guest_code)
{
struct kvm_vcpu *vcpu = __aarch64_vcpu_add(vm, vcpu_id, init);
vcpu_arch_set_entry_point(vcpu, guest_code);
return vcpu;
}
struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
{
return __aarch64_vcpu_add(vm, vcpu_id, NULL);
}
void vcpu_args_set(struct kvm_vcpu *vcpu, unsigned int num, ...)
{
va_list ap;
int i;
TEST_ASSERT(num >= 1 && num <= 8, "Unsupported number of args,\n"
" num: %u", num);
va_start(ap, num);
for (i = 0; i < num; i++) {
vcpu_set_reg(vcpu, ARM64_CORE_REG(regs.regs[i]),
va_arg(ap, uint64_t));
}
va_end(ap);
}
void kvm_exit_unexpected_exception(int vector, uint64_t ec, bool valid_ec)
{
ucall(UCALL_UNHANDLED, 3, vector, ec, valid_ec);
while (1)
;
}
void assert_on_unhandled_exception(struct kvm_vcpu *vcpu)
{
struct ucall uc;
if (get_ucall(vcpu, &uc) != UCALL_UNHANDLED)
return;
if (uc.args[2]) /* valid_ec */ {
assert(VECTOR_IS_SYNC(uc.args[0]));
TEST_FAIL("Unexpected exception (vector:0x%lx, ec:0x%lx)",
uc.args[0], uc.args[1]);
} else {
assert(!VECTOR_IS_SYNC(uc.args[0]));
TEST_FAIL("Unexpected exception (vector:0x%lx)",
uc.args[0]);
}
}
struct handlers {
handler_fn exception_handlers[VECTOR_NUM][ESR_EC_NUM];
};
void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu)
{
extern char vectors;
vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_VBAR_EL1), (uint64_t)&vectors);
}
void route_exception(struct ex_regs *regs, int vector)
{
struct handlers *handlers = (struct handlers *)exception_handlers;
bool valid_ec;
int ec = 0;
switch (vector) {
case VECTOR_SYNC_CURRENT:
case VECTOR_SYNC_LOWER_64:
ec = (read_sysreg(esr_el1) >> ESR_EC_SHIFT) & ESR_EC_MASK;
valid_ec = true;
break;
case VECTOR_IRQ_CURRENT:
case VECTOR_IRQ_LOWER_64:
case VECTOR_FIQ_CURRENT:
case VECTOR_FIQ_LOWER_64:
case VECTOR_ERROR_CURRENT:
case VECTOR_ERROR_LOWER_64:
ec = 0;
valid_ec = false;
break;
default:
valid_ec = false;
goto unexpected_exception;
}
if (handlers && handlers->exception_handlers[vector][ec])
return handlers->exception_handlers[vector][ec](regs);
unexpected_exception:
kvm_exit_unexpected_exception(vector, ec, valid_ec);
}
void vm_init_descriptor_tables(struct kvm_vm *vm)
{
vm->handlers = __vm_vaddr_alloc(vm, sizeof(struct handlers),
vm->page_size, MEM_REGION_DATA);
*(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers;
}
void vm_install_sync_handler(struct kvm_vm *vm, int vector, int ec,
void (*handler)(struct ex_regs *))
{
struct handlers *handlers = addr_gva2hva(vm, vm->handlers);
assert(VECTOR_IS_SYNC(vector));
assert(vector < VECTOR_NUM);
assert(ec < ESR_EC_NUM);
handlers->exception_handlers[vector][ec] = handler;
}
void vm_install_exception_handler(struct kvm_vm *vm, int vector,
void (*handler)(struct ex_regs *))
{
struct handlers *handlers = addr_gva2hva(vm, vm->handlers);
assert(!VECTOR_IS_SYNC(vector));
assert(vector < VECTOR_NUM);
handlers->exception_handlers[vector][0] = handler;
}
uint32_t guest_get_vcpuid(void)
{
return read_sysreg(tpidr_el1);
}
static uint32_t max_ipa_for_page_size(uint32_t vm_ipa, uint32_t gran,
uint32_t not_sup_val, uint32_t ipa52_min_val)
{
if (gran == not_sup_val)
return 0;
else if (gran >= ipa52_min_val && vm_ipa >= 52)
return 52;
else
return min(vm_ipa, 48U);
}
void aarch64_get_supported_page_sizes(uint32_t ipa, uint32_t *ipa4k,
uint32_t *ipa16k, uint32_t *ipa64k)
{
struct kvm_vcpu_init preferred_init;
int kvm_fd, vm_fd, vcpu_fd, err;
uint64_t val;
uint32_t gran;
struct kvm_one_reg reg = {
.id = KVM_ARM64_SYS_REG(SYS_ID_AA64MMFR0_EL1),
.addr = (uint64_t)&val,
};
kvm_fd = open_kvm_dev_path_or_exit();
vm_fd = __kvm_ioctl(kvm_fd, KVM_CREATE_VM, (void *)(unsigned long)ipa);
TEST_ASSERT(vm_fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VM, vm_fd));
vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);
TEST_ASSERT(vcpu_fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VCPU, vcpu_fd));
err = ioctl(vm_fd, KVM_ARM_PREFERRED_TARGET, &preferred_init);
TEST_ASSERT(err == 0, KVM_IOCTL_ERROR(KVM_ARM_PREFERRED_TARGET, err));
err = ioctl(vcpu_fd, KVM_ARM_VCPU_INIT, &preferred_init);
TEST_ASSERT(err == 0, KVM_IOCTL_ERROR(KVM_ARM_VCPU_INIT, err));
err = ioctl(vcpu_fd, KVM_GET_ONE_REG, ®);
TEST_ASSERT(err == 0, KVM_IOCTL_ERROR(KVM_GET_ONE_REG, vcpu_fd));
gran = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN4), val);
*ipa4k = max_ipa_for_page_size(ipa, gran, ID_AA64MMFR0_EL1_TGRAN4_NI,
ID_AA64MMFR0_EL1_TGRAN4_52_BIT);
gran = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN64), val);
*ipa64k = max_ipa_for_page_size(ipa, gran, ID_AA64MMFR0_EL1_TGRAN64_NI,
ID_AA64MMFR0_EL1_TGRAN64_IMP);
gran = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN16), val);
*ipa16k = max_ipa_for_page_size(ipa, gran, ID_AA64MMFR0_EL1_TGRAN16_NI,
ID_AA64MMFR0_EL1_TGRAN16_52_BIT);
close(vcpu_fd);
close(vm_fd);
close(kvm_fd);
}
#define __smccc_call(insn, function_id, arg0, arg1, arg2, arg3, arg4, arg5, \
arg6, res) \
asm volatile("mov w0, %w[function_id]\n" \
"mov x1, %[arg0]\n" \
"mov x2, %[arg1]\n" \
"mov x3, %[arg2]\n" \
"mov x4, %[arg3]\n" \
"mov x5, %[arg4]\n" \
"mov x6, %[arg5]\n" \
"mov x7, %[arg6]\n" \
#insn "#0\n" \
"mov %[res0], x0\n" \
"mov %[res1], x1\n" \
"mov %[res2], x2\n" \
"mov %[res3], x3\n" \
: [res0] "=r"(res->a0), [res1] "=r"(res->a1), \
[res2] "=r"(res->a2), [res3] "=r"(res->a3) \
: [function_id] "r"(function_id), [arg0] "r"(arg0), \
[arg1] "r"(arg1), [arg2] "r"(arg2), [arg3] "r"(arg3), \
[arg4] "r"(arg4), [arg5] "r"(arg5), [arg6] "r"(arg6) \
: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7")
void smccc_hvc(uint32_t function_id, uint64_t arg0, uint64_t arg1,
uint64_t arg2, uint64_t arg3, uint64_t arg4, uint64_t arg5,
uint64_t arg6, struct arm_smccc_res *res)
{
__smccc_call(hvc, function_id, arg0, arg1, arg2, arg3, arg4, arg5,
arg6, res);
}
void smccc_smc(uint32_t function_id, uint64_t arg0, uint64_t arg1,
uint64_t arg2, uint64_t arg3, uint64_t arg4, uint64_t arg5,
uint64_t arg6, struct arm_smccc_res *res)
{
__smccc_call(smc, function_id, arg0, arg1, arg2, arg3, arg4, arg5,
arg6, res);
}
void kvm_selftest_arch_init(void)
{
/*
* arm64 doesn't have a true default mode, so start by computing the
* available IPA space and page sizes early.
*/
guest_modes_append_default();
}
void vm_vaddr_populate_bitmap(struct kvm_vm *vm)
{
/*
* arm64 selftests use only TTBR0_EL1, meaning that the valid VA space
* is [0, 2^(64 - TCR_EL1.T0SZ)).
*/
sparsebit_set_num(vm->vpages_valid, 0,
(1ULL << vm->va_bits) >> vm->page_shift);
}