// SPDX-License-Identifier: GPL-2.0-only
/*
* Test for s390x CMMA migration
*
* Copyright IBM Corp. 2023
*
* Authors:
* Nico Boehr <[email protected]>
*/
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include "test_util.h"
#include "kvm_util.h"
#include "kselftest.h"
#include "ucall_common.h"
#define MAIN_PAGE_COUNT 512
#define TEST_DATA_PAGE_COUNT 512
#define TEST_DATA_MEMSLOT 1
#define TEST_DATA_START_GFN 4096
#define TEST_DATA_TWO_PAGE_COUNT 256
#define TEST_DATA_TWO_MEMSLOT 2
#define TEST_DATA_TWO_START_GFN 8192
static char cmma_value_buf[MAIN_PAGE_COUNT + TEST_DATA_PAGE_COUNT];
/**
* Dirty CMMA attributes of exactly one page in the TEST_DATA memslot,
* so use_cmma goes on and the CMMA related ioctls do something.
*/
static void guest_do_one_essa(void)
{
asm volatile(
/* load TEST_DATA_START_GFN into r1 */
" llilf 1,%[start_gfn]\n"
/* calculate the address from the gfn */
" sllg 1,1,12(0)\n"
/* set the first page in TEST_DATA memslot to STABLE */
" .insn rrf,0xb9ab0000,2,1,1,0\n"
/* hypercall */
" diag 0,0,0x501\n"
"0: j 0b"
:
: [start_gfn] "L"(TEST_DATA_START_GFN)
: "r1", "r2", "memory", "cc"
);
}
/**
* Touch CMMA attributes of all pages in TEST_DATA memslot. Set them to stable
* state.
*/
static void guest_dirty_test_data(void)
{
asm volatile(
/* r1 = TEST_DATA_START_GFN */
" xgr 1,1\n"
" llilf 1,%[start_gfn]\n"
/* r5 = TEST_DATA_PAGE_COUNT */
" lghi 5,%[page_count]\n"
/* r5 += r1 */
"2: agfr 5,1\n"
/* r2 = r1 << 12 */
"1: sllg 2,1,12(0)\n"
/* essa(r4, r2, SET_STABLE) */
" .insn rrf,0xb9ab0000,4,2,1,0\n"
/* i++ */
" agfi 1,1\n"
/* if r1 < r5 goto 1 */
" cgrjl 1,5,1b\n"
/* hypercall */
" diag 0,0,0x501\n"
"0: j 0b"
:
: [start_gfn] "L"(TEST_DATA_START_GFN),
[page_count] "L"(TEST_DATA_PAGE_COUNT)
:
/* the counter in our loop over the pages */
"r1",
/* the calculated page physical address */
"r2",
/* ESSA output register */
"r4",
/* last page */
"r5",
"cc", "memory"
);
}
static void create_main_memslot(struct kvm_vm *vm)
{
int i;
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, MAIN_PAGE_COUNT, 0);
/* set the array of memslots to zero like __vm_create does */
for (i = 0; i < NR_MEM_REGIONS; i++)
vm->memslots[i] = 0;
}
static void create_test_memslot(struct kvm_vm *vm)
{
vm_userspace_mem_region_add(vm,
VM_MEM_SRC_ANONYMOUS,
TEST_DATA_START_GFN << vm->page_shift,
TEST_DATA_MEMSLOT,
TEST_DATA_PAGE_COUNT,
0
);
vm->memslots[MEM_REGION_TEST_DATA] = TEST_DATA_MEMSLOT;
}
static void create_memslots(struct kvm_vm *vm)
{
/*
* Our VM has the following memory layout:
* +------+---------------------------+
* | GFN | Memslot |
* +------+---------------------------+
* | 0 | |
* | ... | MAIN (Code, Stack, ...) |
* | 511 | |
* +------+---------------------------+
* | 4096 | |
* | ... | TEST_DATA |
* | 4607 | |
* +------+---------------------------+
*/
create_main_memslot(vm);
create_test_memslot(vm);
}
static void finish_vm_setup(struct kvm_vm *vm)
{
struct userspace_mem_region *slot0;
kvm_vm_elf_load(vm, program_invocation_name);
slot0 = memslot2region(vm, 0);
ucall_init(vm, slot0->region.guest_phys_addr + slot0->region.memory_size);
kvm_arch_vm_post_create(vm);
}
static struct kvm_vm *create_vm_two_memslots(void)
{
struct kvm_vm *vm;
vm = vm_create_barebones();
create_memslots(vm);
finish_vm_setup(vm);
return vm;
}
static void enable_cmma(struct kvm_vm *vm)
{
int r;
r = __kvm_device_attr_set(vm->fd, KVM_S390_VM_MEM_CTRL, KVM_S390_VM_MEM_ENABLE_CMMA, NULL);
TEST_ASSERT(!r, "enabling cmma failed r=%d errno=%d", r, errno);
}
static void enable_dirty_tracking(struct kvm_vm *vm)
{
vm_mem_region_set_flags(vm, 0, KVM_MEM_LOG_DIRTY_PAGES);
vm_mem_region_set_flags(vm, TEST_DATA_MEMSLOT, KVM_MEM_LOG_DIRTY_PAGES);
}
static int __enable_migration_mode(struct kvm_vm *vm)
{
return __kvm_device_attr_set(vm->fd,
KVM_S390_VM_MIGRATION,
KVM_S390_VM_MIGRATION_START,
NULL
);
}
static void enable_migration_mode(struct kvm_vm *vm)
{
int r = __enable_migration_mode(vm);
TEST_ASSERT(!r, "enabling migration mode failed r=%d errno=%d", r, errno);
}
static bool is_migration_mode_on(struct kvm_vm *vm)
{
u64 out;
int r;
r = __kvm_device_attr_get(vm->fd,
KVM_S390_VM_MIGRATION,
KVM_S390_VM_MIGRATION_STATUS,
&out
);
TEST_ASSERT(!r, "getting migration mode status failed r=%d errno=%d", r, errno);
return out;
}
static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out)
{
struct kvm_s390_cmma_log args;
int rc;
errno = 0;
args = (struct kvm_s390_cmma_log){
.start_gfn = 0,
.count = sizeof(cmma_value_buf),
.flags = flags,
.values = (__u64)&cmma_value_buf[0]
};
rc = __vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args);
*errno_out = errno;
return rc;
}
static void test_get_cmma_basic(void)
{
struct kvm_vm *vm = create_vm_two_memslots();
struct kvm_vcpu *vcpu;
int rc, errno_out;
/* GET_CMMA_BITS without CMMA enabled should fail */
rc = vm_get_cmma_bits(vm, 0, &errno_out);
TEST_ASSERT_EQ(rc, -1);
TEST_ASSERT_EQ(errno_out, ENXIO);
enable_cmma(vm);
vcpu = vm_vcpu_add(vm, 1, guest_do_one_essa);
vcpu_run(vcpu);
/* GET_CMMA_BITS without migration mode and without peeking should fail */
rc = vm_get_cmma_bits(vm, 0, &errno_out);
TEST_ASSERT_EQ(rc, -1);
TEST_ASSERT_EQ(errno_out, EINVAL);
/* GET_CMMA_BITS without migration mode and with peeking should work */
rc = vm_get_cmma_bits(vm, KVM_S390_CMMA_PEEK, &errno_out);
TEST_ASSERT_EQ(rc, 0);
TEST_ASSERT_EQ(errno_out, 0);
enable_dirty_tracking(vm);
enable_migration_mode(vm);
/* GET_CMMA_BITS with invalid flags */
rc = vm_get_cmma_bits(vm, 0xfeedc0fe, &errno_out);
TEST_ASSERT_EQ(rc, -1);
TEST_ASSERT_EQ(errno_out, EINVAL);
kvm_vm_free(vm);
}
static void assert_exit_was_hypercall(struct kvm_vcpu *vcpu)
{
TEST_ASSERT_EQ(vcpu->run->exit_reason, 13);
TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, 4);
TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x8300);
TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipb, 0x5010000);
}
static void test_migration_mode(void)
{
struct kvm_vm *vm = vm_create_barebones();
struct kvm_vcpu *vcpu;
u64 orig_psw;
int rc;
/* enabling migration mode on a VM without memory should fail */
rc = __enable_migration_mode(vm);
TEST_ASSERT_EQ(rc, -1);
TEST_ASSERT_EQ(errno, EINVAL);
TEST_ASSERT(!is_migration_mode_on(vm), "migration mode should still be off");
errno = 0;
create_memslots(vm);
finish_vm_setup(vm);
enable_cmma(vm);
vcpu = vm_vcpu_add(vm, 1, guest_do_one_essa);
orig_psw = vcpu->run->psw_addr;
/*
* Execute one essa instruction in the guest. Otherwise the guest will
* not have use_cmm enabled and GET_CMMA_BITS will return no pages.
*/
vcpu_run(vcpu);
assert_exit_was_hypercall(vcpu);
/* migration mode when memslots have dirty tracking off should fail */
rc = __enable_migration_mode(vm);
TEST_ASSERT_EQ(rc, -1);
TEST_ASSERT_EQ(errno, EINVAL);
TEST_ASSERT(!is_migration_mode_on(vm), "migration mode should still be off");
errno = 0;
/* enable dirty tracking */
enable_dirty_tracking(vm);
/* enabling migration mode should work now */
rc = __enable_migration_mode(vm);
TEST_ASSERT_EQ(rc, 0);
TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on");
errno = 0;
/* execute another ESSA instruction to see this goes fine */
vcpu->run->psw_addr = orig_psw;
vcpu_run(vcpu);
assert_exit_was_hypercall(vcpu);
/*
* With migration mode on, create a new memslot with dirty tracking off.
* This should turn off migration mode.
*/
TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on");
vm_userspace_mem_region_add(vm,
VM_MEM_SRC_ANONYMOUS,
TEST_DATA_TWO_START_GFN << vm->page_shift,
TEST_DATA_TWO_MEMSLOT,
TEST_DATA_TWO_PAGE_COUNT,
0
);
TEST_ASSERT(!is_migration_mode_on(vm),
"creating memslot without dirty tracking turns off migration mode"
);
/* ESSA instructions should still execute fine */
vcpu->run->psw_addr = orig_psw;
vcpu_run(vcpu);
assert_exit_was_hypercall(vcpu);
/*
* Turn on dirty tracking on the new memslot.
* It should be possible to turn migration mode back on again.
*/
vm_mem_region_set_flags(vm, TEST_DATA_TWO_MEMSLOT, KVM_MEM_LOG_DIRTY_PAGES);
rc = __enable_migration_mode(vm);
TEST_ASSERT_EQ(rc, 0);
TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on");
errno = 0;
/*
* Turn off dirty tracking again, this time with just a flag change.
* Again, migration mode should turn off.
*/
TEST_ASSERT(is_migration_mode_on(vm), "migration mode should be on");
vm_mem_region_set_flags(vm, TEST_DATA_TWO_MEMSLOT, 0);
TEST_ASSERT(!is_migration_mode_on(vm),
"disabling dirty tracking should turn off migration mode"
);
/* ESSA instructions should still execute fine */
vcpu->run->psw_addr = orig_psw;
vcpu_run(vcpu);
assert_exit_was_hypercall(vcpu);
kvm_vm_free(vm);
}
/**
* Given a VM with the MAIN and TEST_DATA memslot, assert that both slots have
* CMMA attributes of all pages in both memslots and nothing more dirty.
* This has the useful side effect of ensuring nothing is CMMA dirty after this
* function.
*/
static void assert_all_slots_cmma_dirty(struct kvm_vm *vm)
{
struct kvm_s390_cmma_log args;
/*
* First iteration - everything should be dirty.
* Start at the main memslot...
*/
args = (struct kvm_s390_cmma_log){
.start_gfn = 0,
.count = sizeof(cmma_value_buf),
.flags = 0,
.values = (__u64)&cmma_value_buf[0]
};
memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf));
vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args);
TEST_ASSERT_EQ(args.count, MAIN_PAGE_COUNT);
TEST_ASSERT_EQ(args.remaining, TEST_DATA_PAGE_COUNT);
TEST_ASSERT_EQ(args.start_gfn, 0);
/* ...and then - after a hole - the TEST_DATA memslot should follow */
args = (struct kvm_s390_cmma_log){
.start_gfn = MAIN_PAGE_COUNT,
.count = sizeof(cmma_value_buf),
.flags = 0,
.values = (__u64)&cmma_value_buf[0]
};
memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf));
vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args);
TEST_ASSERT_EQ(args.count, TEST_DATA_PAGE_COUNT);
TEST_ASSERT_EQ(args.start_gfn, TEST_DATA_START_GFN);
TEST_ASSERT_EQ(args.remaining, 0);
/* ...and nothing else should be there */
args = (struct kvm_s390_cmma_log){
.start_gfn = TEST_DATA_START_GFN + TEST_DATA_PAGE_COUNT,
.count = sizeof(cmma_value_buf),
.flags = 0,
.values = (__u64)&cmma_value_buf[0]
};
memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf));
vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args);
TEST_ASSERT_EQ(args.count, 0);
TEST_ASSERT_EQ(args.start_gfn, 0);
TEST_ASSERT_EQ(args.remaining, 0);
}
/**
* Given a VM, assert no pages are CMMA dirty.
*/
static void assert_no_pages_cmma_dirty(struct kvm_vm *vm)
{
struct kvm_s390_cmma_log args;
/* If we start from GFN 0 again, nothing should be dirty. */
args = (struct kvm_s390_cmma_log){
.start_gfn = 0,
.count = sizeof(cmma_value_buf),
.flags = 0,
.values = (__u64)&cmma_value_buf[0]
};
memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf));
vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args);
if (args.count || args.remaining || args.start_gfn)
TEST_FAIL("pages are still dirty start_gfn=0x%llx count=%u remaining=%llu",
args.start_gfn,
args.count,
args.remaining
);
}
static void test_get_inital_dirty(void)
{
struct kvm_vm *vm = create_vm_two_memslots();
struct kvm_vcpu *vcpu;
enable_cmma(vm);
vcpu = vm_vcpu_add(vm, 1, guest_do_one_essa);
/*
* Execute one essa instruction in the guest. Otherwise the guest will
* not have use_cmm enabled and GET_CMMA_BITS will return no pages.
*/
vcpu_run(vcpu);
assert_exit_was_hypercall(vcpu);
enable_dirty_tracking(vm);
enable_migration_mode(vm);
assert_all_slots_cmma_dirty(vm);
/* Start from the beginning again and make sure nothing else is dirty */
assert_no_pages_cmma_dirty(vm);
kvm_vm_free(vm);
}
static void query_cmma_range(struct kvm_vm *vm,
u64 start_gfn, u64 gfn_count,
struct kvm_s390_cmma_log *res_out)
{
*res_out = (struct kvm_s390_cmma_log){
.start_gfn = start_gfn,
.count = gfn_count,
.flags = 0,
.values = (__u64)&cmma_value_buf[0]
};
memset(cmma_value_buf, 0xff, sizeof(cmma_value_buf));
vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, res_out);
}
/**
* Assert the given cmma_log struct that was executed by query_cmma_range()
* indicates the first dirty gfn is at first_dirty_gfn and contains exactly
* dirty_gfn_count CMMA values.
*/
static void assert_cmma_dirty(u64 first_dirty_gfn,
u64 dirty_gfn_count,
const struct kvm_s390_cmma_log *res)
{
TEST_ASSERT_EQ(res->start_gfn, first_dirty_gfn);
TEST_ASSERT_EQ(res->count, dirty_gfn_count);
for (size_t i = 0; i < dirty_gfn_count; i++)
TEST_ASSERT_EQ(cmma_value_buf[0], 0x0); /* stable state */
TEST_ASSERT_EQ(cmma_value_buf[dirty_gfn_count], 0xff); /* not touched */
}
static void test_get_skip_holes(void)
{
size_t gfn_offset;
struct kvm_vm *vm = create_vm_two_memslots();
struct kvm_s390_cmma_log log;
struct kvm_vcpu *vcpu;
u64 orig_psw;
enable_cmma(vm);
vcpu = vm_vcpu_add(vm, 1, guest_dirty_test_data);
orig_psw = vcpu->run->psw_addr;
/*
* Execute some essa instructions in the guest. Otherwise the guest will
* not have use_cmm enabled and GET_CMMA_BITS will return no pages.
*/
vcpu_run(vcpu);
assert_exit_was_hypercall(vcpu);
enable_dirty_tracking(vm);
enable_migration_mode(vm);
/* un-dirty all pages */
assert_all_slots_cmma_dirty(vm);
/* Then, dirty just the TEST_DATA memslot */
vcpu->run->psw_addr = orig_psw;
vcpu_run(vcpu);
gfn_offset = TEST_DATA_START_GFN;
/**
* Query CMMA attributes of one page, starting at page 0. Since the
* main memslot was not touched by the VM, this should yield the first
* page of the TEST_DATA memslot.
* The dirty bitmap should now look like this:
* 0: not dirty
* [0x1, 0x200): dirty
*/
query_cmma_range(vm, 0, 1, &log);
assert_cmma_dirty(gfn_offset, 1, &log);
gfn_offset++;
/**
* Query CMMA attributes of 32 (0x20) pages past the end of the TEST_DATA
* memslot. This should wrap back to the beginning of the TEST_DATA
* memslot, page 1.
* The dirty bitmap should now look like this:
* [0, 0x21): not dirty
* [0x21, 0x200): dirty
*/
query_cmma_range(vm, TEST_DATA_START_GFN + TEST_DATA_PAGE_COUNT, 0x20, &log);
assert_cmma_dirty(gfn_offset, 0x20, &log);
gfn_offset += 0x20;
/* Skip 32 pages */
gfn_offset += 0x20;
/**
* After skipping 32 pages, query the next 32 (0x20) pages.
* The dirty bitmap should now look like this:
* [0, 0x21): not dirty
* [0x21, 0x41): dirty
* [0x41, 0x61): not dirty
* [0x61, 0x200): dirty
*/
query_cmma_range(vm, gfn_offset, 0x20, &log);
assert_cmma_dirty(gfn_offset, 0x20, &log);
gfn_offset += 0x20;
/**
* Query 1 page from the beginning of the TEST_DATA memslot. This should
* yield page 0x21.
* The dirty bitmap should now look like this:
* [0, 0x22): not dirty
* [0x22, 0x41): dirty
* [0x41, 0x61): not dirty
* [0x61, 0x200): dirty
*/
query_cmma_range(vm, TEST_DATA_START_GFN, 1, &log);
assert_cmma_dirty(TEST_DATA_START_GFN + 0x21, 1, &log);
gfn_offset++;
/**
* Query 15 (0xF) pages from page 0x23 in TEST_DATA memslot.
* This should yield pages [0x23, 0x33).
* The dirty bitmap should now look like this:
* [0, 0x22): not dirty
* 0x22: dirty
* [0x23, 0x33): not dirty
* [0x33, 0x41): dirty
* [0x41, 0x61): not dirty
* [0x61, 0x200): dirty
*/
gfn_offset = TEST_DATA_START_GFN + 0x23;
query_cmma_range(vm, gfn_offset, 15, &log);
assert_cmma_dirty(gfn_offset, 15, &log);
/**
* Query 17 (0x11) pages from page 0x22 in TEST_DATA memslot.
* This should yield page [0x22, 0x33)
* The dirty bitmap should now look like this:
* [0, 0x33): not dirty
* [0x33, 0x41): dirty
* [0x41, 0x61): not dirty
* [0x61, 0x200): dirty
*/
gfn_offset = TEST_DATA_START_GFN + 0x22;
query_cmma_range(vm, gfn_offset, 17, &log);
assert_cmma_dirty(gfn_offset, 17, &log);
/**
* Query 25 (0x19) pages from page 0x40 in TEST_DATA memslot.
* This should yield page 0x40 and nothing more, since there are more
* than 16 non-dirty pages after page 0x40.
* The dirty bitmap should now look like this:
* [0, 0x33): not dirty
* [0x33, 0x40): dirty
* [0x40, 0x61): not dirty
* [0x61, 0x200): dirty
*/
gfn_offset = TEST_DATA_START_GFN + 0x40;
query_cmma_range(vm, gfn_offset, 25, &log);
assert_cmma_dirty(gfn_offset, 1, &log);
/**
* Query pages [0x33, 0x40).
* The dirty bitmap should now look like this:
* [0, 0x61): not dirty
* [0x61, 0x200): dirty
*/
gfn_offset = TEST_DATA_START_GFN + 0x33;
query_cmma_range(vm, gfn_offset, 0x40 - 0x33, &log);
assert_cmma_dirty(gfn_offset, 0x40 - 0x33, &log);
/**
* Query the remaining pages [0x61, 0x200).
*/
gfn_offset = TEST_DATA_START_GFN;
query_cmma_range(vm, gfn_offset, TEST_DATA_PAGE_COUNT - 0x61, &log);
assert_cmma_dirty(TEST_DATA_START_GFN + 0x61, TEST_DATA_PAGE_COUNT - 0x61, &log);
assert_no_pages_cmma_dirty(vm);
}
struct testdef {
const char *name;
void (*test)(void);
} testlist[] = {
{ "migration mode and dirty tracking", test_migration_mode },
{ "GET_CMMA_BITS: basic calls", test_get_cmma_basic },
{ "GET_CMMA_BITS: all pages are dirty initally", test_get_inital_dirty },
{ "GET_CMMA_BITS: holes are skipped", test_get_skip_holes },
};
/**
* The kernel may support CMMA, but the machine may not (i.e. if running as
* guest-3).
*
* In this case, the CMMA capabilities are all there, but the CMMA-related
* ioctls fail. To find out whether the machine supports CMMA, create a
* temporary VM and then query the CMMA feature of the VM.
*/
static int machine_has_cmma(void)
{
struct kvm_vm *vm = vm_create_barebones();
int r;
r = !__kvm_has_device_attr(vm->fd, KVM_S390_VM_MEM_CTRL, KVM_S390_VM_MEM_ENABLE_CMMA);
kvm_vm_free(vm);
return r;
}
int main(int argc, char *argv[])
{
int idx;
TEST_REQUIRE(kvm_has_cap(KVM_CAP_SYNC_REGS));
TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_CMMA_MIGRATION));
TEST_REQUIRE(machine_has_cmma());
ksft_print_header();
ksft_set_plan(ARRAY_SIZE(testlist));
for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) {
testlist[idx].test();
ksft_test_result_pass("%s\n", testlist[idx].name);
}
ksft_finished(); /* Print results and exit() accordingly */
}
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