// SPDX-License-Identifier: GPL-2.0
#include <fcntl.h>
#include <pthread.h>
#include <sched.h>
#include <semaphore.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/compiler.h>
#include <test_util.h>
#include <kvm_util.h>
#include <processor.h>
/*
* s390x needs at least 1MB alignment, and the x86_64 MOVE/DELETE tests need a
* 2MB sized and aligned region so that the initial region corresponds to
* exactly one large page.
*/
#define MEM_REGION_SIZE 0x200000
#ifdef __x86_64__
/*
* Somewhat arbitrary location and slot, intended to not overlap anything.
*/
#define MEM_REGION_GPA 0xc0000000
#define MEM_REGION_SLOT 10
static const uint64_t MMIO_VAL = 0xbeefull;
extern const uint64_t final_rip_start;
extern const uint64_t final_rip_end;
static sem_t vcpu_ready;
static inline uint64_t guest_spin_on_val(uint64_t spin_val)
{
uint64_t val;
do {
val = READ_ONCE(*((uint64_t *)MEM_REGION_GPA));
} while (val == spin_val);
GUEST_SYNC(0);
return val;
}
static void *vcpu_worker(void *data)
{
struct kvm_vcpu *vcpu = data;
struct kvm_run *run = vcpu->run;
struct ucall uc;
uint64_t cmd;
/*
* Loop until the guest is done. Re-enter the guest on all MMIO exits,
* which will occur if the guest attempts to access a memslot after it
* has been deleted or while it is being moved .
*/
while (1) {
vcpu_run(vcpu);
if (run->exit_reason == KVM_EXIT_IO) {
cmd = get_ucall(vcpu, &uc);
if (cmd != UCALL_SYNC)
break;
sem_post(&vcpu_ready);
continue;
}
if (run->exit_reason != KVM_EXIT_MMIO)
break;
TEST_ASSERT(!run->mmio.is_write, "Unexpected exit mmio write");
TEST_ASSERT(run->mmio.len == 8,
"Unexpected exit mmio size = %u", run->mmio.len);
TEST_ASSERT(run->mmio.phys_addr == MEM_REGION_GPA,
"Unexpected exit mmio address = 0x%llx",
run->mmio.phys_addr);
memcpy(run->mmio.data, &MMIO_VAL, 8);
}
if (run->exit_reason == KVM_EXIT_IO && cmd == UCALL_ABORT)
REPORT_GUEST_ASSERT(uc);
return NULL;
}
static void wait_for_vcpu(void)
{
struct timespec ts;
TEST_ASSERT(!clock_gettime(CLOCK_REALTIME, &ts),
"clock_gettime() failed: %d", errno);
ts.tv_sec += 2;
TEST_ASSERT(!sem_timedwait(&vcpu_ready, &ts),
"sem_timedwait() failed: %d", errno);
/* Wait for the vCPU thread to reenter the guest. */
usleep(100000);
}
static struct kvm_vm *spawn_vm(struct kvm_vcpu **vcpu, pthread_t *vcpu_thread,
void *guest_code)
{
struct kvm_vm *vm;
uint64_t *hva;
uint64_t gpa;
vm = vm_create_with_one_vcpu(vcpu, guest_code);
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS_THP,
MEM_REGION_GPA, MEM_REGION_SLOT,
MEM_REGION_SIZE / getpagesize(), 0);
/*
* Allocate and map two pages so that the GPA accessed by guest_code()
* stays valid across the memslot move.
*/
gpa = vm_phy_pages_alloc(vm, 2, MEM_REGION_GPA, MEM_REGION_SLOT);
TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc\n");
virt_map(vm, MEM_REGION_GPA, MEM_REGION_GPA, 2);
/* Ditto for the host mapping so that both pages can be zeroed. */
hva = addr_gpa2hva(vm, MEM_REGION_GPA);
memset(hva, 0, 2 * 4096);
pthread_create(vcpu_thread, NULL, vcpu_worker, *vcpu);
/* Ensure the guest thread is spun up. */
wait_for_vcpu();
return vm;
}
static void guest_code_move_memory_region(void)
{
uint64_t val;
GUEST_SYNC(0);
/*
* Spin until the memory region starts getting moved to a
* misaligned address.
* Every region move may or may not trigger MMIO, as the
* window where the memslot is invalid is usually quite small.
*/
val = guest_spin_on_val(0);
__GUEST_ASSERT(val == 1 || val == MMIO_VAL,
"Expected '1' or MMIO ('%lx'), got '%lx'", MMIO_VAL, val);
/* Spin until the misaligning memory region move completes. */
val = guest_spin_on_val(MMIO_VAL);
__GUEST_ASSERT(val == 1 || val == 0,
"Expected '0' or '1' (no MMIO), got '%lx'", val);
/* Spin until the memory region starts to get re-aligned. */
val = guest_spin_on_val(0);
__GUEST_ASSERT(val == 1 || val == MMIO_VAL,
"Expected '1' or MMIO ('%lx'), got '%lx'", MMIO_VAL, val);
/* Spin until the re-aligning memory region move completes. */
val = guest_spin_on_val(MMIO_VAL);
GUEST_ASSERT_EQ(val, 1);
GUEST_DONE();
}
static void test_move_memory_region(void)
{
pthread_t vcpu_thread;
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
uint64_t *hva;
vm = spawn_vm(&vcpu, &vcpu_thread, guest_code_move_memory_region);
hva = addr_gpa2hva(vm, MEM_REGION_GPA);
/*
* Shift the region's base GPA. The guest should not see "2" as the
* hva->gpa translation is misaligned, i.e. the guest is accessing a
* different host pfn.
*/
vm_mem_region_move(vm, MEM_REGION_SLOT, MEM_REGION_GPA - 4096);
WRITE_ONCE(*hva, 2);
/*
* The guest _might_ see an invalid memslot and trigger MMIO, but it's
* a tiny window. Spin and defer the sync until the memslot is
* restored and guest behavior is once again deterministic.
*/
usleep(100000);
/*
* Note, value in memory needs to be changed *before* restoring the
* memslot, else the guest could race the update and see "2".
*/
WRITE_ONCE(*hva, 1);
/* Restore the original base, the guest should see "1". */
vm_mem_region_move(vm, MEM_REGION_SLOT, MEM_REGION_GPA);
wait_for_vcpu();
/* Defered sync from when the memslot was misaligned (above). */
wait_for_vcpu();
pthread_join(vcpu_thread, NULL);
kvm_vm_free(vm);
}
static void guest_code_delete_memory_region(void)
{
struct desc_ptr idt;
uint64_t val;
/*
* Clobber the IDT so that a #PF due to the memory region being deleted
* escalates to triple-fault shutdown. Because the memory region is
* deleted, there will be no valid mappings. As a result, KVM will
* repeatedly intercepts the state-2 page fault that occurs when trying
* to vector the guest's #PF. I.e. trying to actually handle the #PF
* in the guest will never succeed, and so isn't an option.
*/
memset(&idt, 0, sizeof(idt));
__asm__ __volatile__("lidt %0" :: "m"(idt));
GUEST_SYNC(0);
/* Spin until the memory region is deleted. */
val = guest_spin_on_val(0);
GUEST_ASSERT_EQ(val, MMIO_VAL);
/* Spin until the memory region is recreated. */
val = guest_spin_on_val(MMIO_VAL);
GUEST_ASSERT_EQ(val, 0);
/* Spin until the memory region is deleted. */
val = guest_spin_on_val(0);
GUEST_ASSERT_EQ(val, MMIO_VAL);
asm("1:\n\t"
".pushsection .rodata\n\t"
".global final_rip_start\n\t"
"final_rip_start: .quad 1b\n\t"
".popsection");
/* Spin indefinitely (until the code memslot is deleted). */
guest_spin_on_val(MMIO_VAL);
asm("1:\n\t"
".pushsection .rodata\n\t"
".global final_rip_end\n\t"
"final_rip_end: .quad 1b\n\t"
".popsection");
GUEST_ASSERT(0);
}
static void test_delete_memory_region(void)
{
pthread_t vcpu_thread;
struct kvm_vcpu *vcpu;
struct kvm_regs regs;
struct kvm_run *run;
struct kvm_vm *vm;
vm = spawn_vm(&vcpu, &vcpu_thread, guest_code_delete_memory_region);
/* Delete the memory region, the guest should not die. */
vm_mem_region_delete(vm, MEM_REGION_SLOT);
wait_for_vcpu();
/* Recreate the memory region. The guest should see "0". */
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS_THP,
MEM_REGION_GPA, MEM_REGION_SLOT,
MEM_REGION_SIZE / getpagesize(), 0);
wait_for_vcpu();
/* Delete the region again so that there's only one memslot left. */
vm_mem_region_delete(vm, MEM_REGION_SLOT);
wait_for_vcpu();
/*
* Delete the primary memslot. This should cause an emulation error or
* shutdown due to the page tables getting nuked.
*/
vm_mem_region_delete(vm, 0);
pthread_join(vcpu_thread, NULL);
run = vcpu->run;
TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN ||
run->exit_reason == KVM_EXIT_INTERNAL_ERROR,
"Unexpected exit reason = %d", run->exit_reason);
vcpu_regs_get(vcpu, ®s);
/*
* On AMD, after KVM_EXIT_SHUTDOWN the VMCB has been reinitialized already,
* so the instruction pointer would point to the reset vector.
*/
if (run->exit_reason == KVM_EXIT_INTERNAL_ERROR)
TEST_ASSERT(regs.rip >= final_rip_start &&
regs.rip < final_rip_end,
"Bad rip, expected 0x%lx - 0x%lx, got 0x%llx",
final_rip_start, final_rip_end, regs.rip);
kvm_vm_free(vm);
}
static void test_zero_memory_regions(void)
{
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
pr_info("Testing KVM_RUN with zero added memory regions\n");
vm = vm_create_barebones();
vcpu = __vm_vcpu_add(vm, 0);
vm_ioctl(vm, KVM_SET_NR_MMU_PAGES, (void *)64ul);
vcpu_run(vcpu);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR);
kvm_vm_free(vm);
}
#endif /* __x86_64__ */
static void test_invalid_memory_region_flags(void)
{
uint32_t supported_flags = KVM_MEM_LOG_DIRTY_PAGES;
const uint32_t v2_only_flags = KVM_MEM_GUEST_MEMFD;
struct kvm_vm *vm;
int r, i;
#if defined __aarch64__ || defined __riscv || defined __x86_64__
supported_flags |= KVM_MEM_READONLY;
#endif
#ifdef __x86_64__
if (kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM))
vm = vm_create_barebones_type(KVM_X86_SW_PROTECTED_VM);
else
#endif
vm = vm_create_barebones();
if (kvm_check_cap(KVM_CAP_MEMORY_ATTRIBUTES) & KVM_MEMORY_ATTRIBUTE_PRIVATE)
supported_flags |= KVM_MEM_GUEST_MEMFD;
for (i = 0; i < 32; i++) {
if ((supported_flags & BIT(i)) && !(v2_only_flags & BIT(i)))
continue;
r = __vm_set_user_memory_region(vm, 0, BIT(i),
0, MEM_REGION_SIZE, NULL);
TEST_ASSERT(r && errno == EINVAL,
"KVM_SET_USER_MEMORY_REGION should have failed on v2 only flag 0x%lx", BIT(i));
if (supported_flags & BIT(i))
continue;
r = __vm_set_user_memory_region2(vm, 0, BIT(i),
0, MEM_REGION_SIZE, NULL, 0, 0);
TEST_ASSERT(r && errno == EINVAL,
"KVM_SET_USER_MEMORY_REGION2 should have failed on unsupported flag 0x%lx", BIT(i));
}
if (supported_flags & KVM_MEM_GUEST_MEMFD) {
int guest_memfd = vm_create_guest_memfd(vm, MEM_REGION_SIZE, 0);
r = __vm_set_user_memory_region2(vm, 0,
KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_GUEST_MEMFD,
0, MEM_REGION_SIZE, NULL, guest_memfd, 0);
TEST_ASSERT(r && errno == EINVAL,
"KVM_SET_USER_MEMORY_REGION2 should have failed, dirty logging private memory is unsupported");
r = __vm_set_user_memory_region2(vm, 0,
KVM_MEM_READONLY | KVM_MEM_GUEST_MEMFD,
0, MEM_REGION_SIZE, NULL, guest_memfd, 0);
TEST_ASSERT(r && errno == EINVAL,
"KVM_SET_USER_MEMORY_REGION2 should have failed, read-only GUEST_MEMFD memslots are unsupported");
close(guest_memfd);
}
}
/*
* Test it can be added memory slots up to KVM_CAP_NR_MEMSLOTS, then any
* tentative to add further slots should fail.
*/
static void test_add_max_memory_regions(void)
{
int ret;
struct kvm_vm *vm;
uint32_t max_mem_slots;
uint32_t slot;
void *mem, *mem_aligned, *mem_extra;
size_t alignment;
#ifdef __s390x__
/* On s390x, the host address must be aligned to 1M (due to PGSTEs) */
alignment = 0x100000;
#else
alignment = 1;
#endif
max_mem_slots = kvm_check_cap(KVM_CAP_NR_MEMSLOTS);
TEST_ASSERT(max_mem_slots > 0,
"KVM_CAP_NR_MEMSLOTS should be greater than 0");
pr_info("Allowed number of memory slots: %i\n", max_mem_slots);
vm = vm_create_barebones();
/* Check it can be added memory slots up to the maximum allowed */
pr_info("Adding slots 0..%i, each memory region with %dK size\n",
(max_mem_slots - 1), MEM_REGION_SIZE >> 10);
mem = mmap(NULL, (size_t)max_mem_slots * MEM_REGION_SIZE + alignment,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host");
mem_aligned = (void *)(((size_t) mem + alignment - 1) & ~(alignment - 1));
for (slot = 0; slot < max_mem_slots; slot++)
vm_set_user_memory_region(vm, slot, 0,
((uint64_t)slot * MEM_REGION_SIZE),
MEM_REGION_SIZE,
mem_aligned + (uint64_t)slot * MEM_REGION_SIZE);
/* Check it cannot be added memory slots beyond the limit */
mem_extra = mmap(NULL, MEM_REGION_SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
TEST_ASSERT(mem_extra != MAP_FAILED, "Failed to mmap() host");
ret = __vm_set_user_memory_region(vm, max_mem_slots, 0,
(uint64_t)max_mem_slots * MEM_REGION_SIZE,
MEM_REGION_SIZE, mem_extra);
TEST_ASSERT(ret == -1 && errno == EINVAL,
"Adding one more memory slot should fail with EINVAL");
munmap(mem, (size_t)max_mem_slots * MEM_REGION_SIZE + alignment);
munmap(mem_extra, MEM_REGION_SIZE);
kvm_vm_free(vm);
}
#ifdef __x86_64__
static void test_invalid_guest_memfd(struct kvm_vm *vm, int memfd,
size_t offset, const char *msg)
{
int r = __vm_set_user_memory_region2(vm, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA, MEM_REGION_SIZE,
0, memfd, offset);
TEST_ASSERT(r == -1 && errno == EINVAL, "%s", msg);
}
static void test_add_private_memory_region(void)
{
struct kvm_vm *vm, *vm2;
int memfd, i;
pr_info("Testing ADD of KVM_MEM_GUEST_MEMFD memory regions\n");
vm = vm_create_barebones_type(KVM_X86_SW_PROTECTED_VM);
test_invalid_guest_memfd(vm, vm->kvm_fd, 0, "KVM fd should fail");
test_invalid_guest_memfd(vm, vm->fd, 0, "VM's fd should fail");
memfd = kvm_memfd_alloc(MEM_REGION_SIZE, false);
test_invalid_guest_memfd(vm, memfd, 0, "Regular memfd() should fail");
close(memfd);
vm2 = vm_create_barebones_type(KVM_X86_SW_PROTECTED_VM);
memfd = vm_create_guest_memfd(vm2, MEM_REGION_SIZE, 0);
test_invalid_guest_memfd(vm, memfd, 0, "Other VM's guest_memfd() should fail");
vm_set_user_memory_region2(vm2, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA, MEM_REGION_SIZE, 0, memfd, 0);
close(memfd);
kvm_vm_free(vm2);
memfd = vm_create_guest_memfd(vm, MEM_REGION_SIZE, 0);
for (i = 1; i < PAGE_SIZE; i++)
test_invalid_guest_memfd(vm, memfd, i, "Unaligned offset should fail");
vm_set_user_memory_region2(vm, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA, MEM_REGION_SIZE, 0, memfd, 0);
close(memfd);
kvm_vm_free(vm);
}
static void test_add_overlapping_private_memory_regions(void)
{
struct kvm_vm *vm;
int memfd;
int r;
pr_info("Testing ADD of overlapping KVM_MEM_GUEST_MEMFD memory regions\n");
vm = vm_create_barebones_type(KVM_X86_SW_PROTECTED_VM);
memfd = vm_create_guest_memfd(vm, MEM_REGION_SIZE * 4, 0);
vm_set_user_memory_region2(vm, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA, MEM_REGION_SIZE * 2, 0, memfd, 0);
vm_set_user_memory_region2(vm, MEM_REGION_SLOT + 1, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA * 2, MEM_REGION_SIZE * 2,
0, memfd, MEM_REGION_SIZE * 2);
/*
* Delete the first memslot, and then attempt to recreate it except
* with a "bad" offset that results in overlap in the guest_memfd().
*/
vm_set_user_memory_region2(vm, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA, 0, NULL, -1, 0);
/* Overlap the front half of the other slot. */
r = __vm_set_user_memory_region2(vm, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA * 2 - MEM_REGION_SIZE,
MEM_REGION_SIZE * 2,
0, memfd, 0);
TEST_ASSERT(r == -1 && errno == EEXIST, "%s",
"Overlapping guest_memfd() bindings should fail with EEXIST");
/* And now the back half of the other slot. */
r = __vm_set_user_memory_region2(vm, MEM_REGION_SLOT, KVM_MEM_GUEST_MEMFD,
MEM_REGION_GPA * 2 + MEM_REGION_SIZE,
MEM_REGION_SIZE * 2,
0, memfd, 0);
TEST_ASSERT(r == -1 && errno == EEXIST, "%s",
"Overlapping guest_memfd() bindings should fail with EEXIST");
close(memfd);
kvm_vm_free(vm);
}
#endif
int main(int argc, char *argv[])
{
#ifdef __x86_64__
int i, loops;
/*
* FIXME: the zero-memslot test fails on aarch64 and s390x because
* KVM_RUN fails with ENOEXEC or EFAULT.
*/
test_zero_memory_regions();
#endif
test_invalid_memory_region_flags();
test_add_max_memory_regions();
#ifdef __x86_64__
if (kvm_has_cap(KVM_CAP_GUEST_MEMFD) &&
(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM))) {
test_add_private_memory_region();
test_add_overlapping_private_memory_regions();
} else {
pr_info("Skipping tests for KVM_MEM_GUEST_MEMFD memory regions\n");
}
if (argc > 1)
loops = atoi_positive("Number of iterations", argv[1]);
else
loops = 10;
pr_info("Testing MOVE of in-use region, %d loops\n", loops);
for (i = 0; i < loops; i++)
test_move_memory_region();
pr_info("Testing DELETE of in-use region, %d loops\n", loops);
for (i = 0; i < loops; i++)
test_delete_memory_region();
#endif
return 0;
}
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