We know that if a system supports multiple hugetlb page sizes, the desired hugetlb page size can be specified in bits [26:31] of the mmap() flag arguments. The value in these 6 bits will be the shift of each hugetlb page size.

So add a macro to get the page size shift and then calculate the corresponding hugetlb page size, using flag x.

Cc: Ben Gardon bgardon@google.com Cc: Ingo Molnar mingo@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Arnd Bergmann arnd@arndb.de Cc: Michael Kerrisk mtk.manpages@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Suggested-by: Ben Gardon bgardon@google.com Signed-off-by: Yanan Wang wangyanan55@huawei.com Reviewed-by: Ben Gardon bgardon@google.com --- include/uapi/linux/mman.h | 2 ++ tools/include/uapi/linux/mman.h | 2 ++ 2 files changed, 4 insertions(+)

diff --git a/include/uapi/linux/mman.h b/include/uapi/linux/mman.h index f55bc680b5b0..d72df73b182d 100644 --- a/include/uapi/linux/mman.h +++ b/include/uapi/linux/mman.h @@ -41,4 +41,6 @@ #define MAP_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB #define MAP_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB

+#define MAP_HUGE_PAGE_SIZE(x) (1ULL << ((x >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK)) + #endif /* _UAPI_LINUX_MMAN_H */ diff --git a/tools/include/uapi/linux/mman.h b/tools/include/uapi/linux/mman.h index f55bc680b5b0..d72df73b182d 100644 --- a/tools/include/uapi/linux/mman.h +++ b/tools/include/uapi/linux/mman.h @@ -41,4 +41,6 @@ #define MAP_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB #define MAP_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB

+#define MAP_HUGE_PAGE_SIZE(x) (1ULL << ((x >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK)) + #endif /* _UAPI_LINUX_MMAN_H */

Print the errno besides error-string in TEST_ASSERT in the format of "errno=%d - %s" will explicitly indicate that the string is an error information. Besides, the errno is easier to be used for debugging than the error-string.

Suggested-by: Andrew Jones drjones@redhat.com Signed-off-by: Yanan Wang wangyanan55@huawei.com Reviewed-by: Andrew Jones drjones@redhat.com --- tools/testing/selftests/kvm/lib/assert.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/assert.c b/tools/testing/selftests/kvm/lib/assert.c index 5ebbd0d6b472..71ade6100fd3 100644 --- a/tools/testing/selftests/kvm/lib/assert.c +++ b/tools/testing/selftests/kvm/lib/assert.c @@ -71,9 +71,9 @@ test_assert(bool exp, const char *exp_str,

fprintf(stderr, "==== Test Assertion Failure ====\n" " %s:%u: %s\n" - " pid=%d tid=%d - %s\n", + " pid=%d tid=%d errno=%d - %s\n", file, line, exp_str, getpid(), _gettid(), - strerror(errno)); + errno, strerror(errno)); test_dump_stack(); if (fmt) { fputs(" ", stderr);

If we want to have some tests about transparent hugepages, the system configured THP hugepage size should better be known by the tests, which can be used for kinds of alignment or guest memory accessing of vcpus... So it makes sense to add a helper to get the transparent hugepage size.

With VM_MEM_SRC_ANONYMOUS_THP specified in vm_userspace_mem_region_add(), we now stat /sys/kernel/mm/transparent_hugepage to check whether THP is configured in the host kernel before madvise(). Based on this, we can also read file /sys/kernel/mm/transparent_hugepage/hpage_pmd_size to get THP hugepage size.

Signed-off-by: Yanan Wang wangyanan55@huawei.com Reviewed-by: Ben Gardon bgardon@google.com Reviewed-by: Andrew Jones drjones@redhat.com --- .../testing/selftests/kvm/include/test_util.h | 2 ++ tools/testing/selftests/kvm/lib/test_util.c | 29 +++++++++++++++++++ 2 files changed, 31 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index b7f41399f22c..ef24c76ba89a 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -78,6 +78,8 @@ struct vm_mem_backing_src_alias { enum vm_mem_backing_src_type type; };

+bool thp_configured(void); +size_t get_trans_hugepagesz(void); void backing_src_help(void); enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name);

diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index c7c0627c6842..efc1a7782de0 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -10,6 +10,7 @@ #include <limits.h> #include <stdlib.h> #include <time.h> +#include <sys/stat.h> #include "linux/kernel.h"

#include "test_util.h" @@ -117,6 +118,34 @@ const struct vm_mem_backing_src_alias backing_src_aliases[] = { {"anonymous_hugetlb", VM_MEM_SRC_ANONYMOUS_HUGETLB,}, };

+bool thp_configured(void) +{ + int ret; + struct stat statbuf; + + ret = stat("/sys/kernel/mm/transparent_hugepage", &statbuf); + TEST_ASSERT(ret == 0 || (ret == -1 && errno == ENOENT), + "Error in stating /sys/kernel/mm/transparent_hugepage"); + + return ret == 0; +} + +size_t get_trans_hugepagesz(void) +{ + size_t size; + FILE *f; + + TEST_ASSERT(thp_configured(), "THP is not configured in host kernel"); + + f = fopen("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size", "r"); + TEST_ASSERT(f != NULL, "Error in opening transparent_hugepage/hpage_pmd_size"); + + fscanf(f, "%ld", &size); + fclose(f); + + return size; +} + void backing_src_help(void) { int i;

With VM_MEM_SRC_ANONYMOUS_HUGETLB, we currently can only use system default hugetlb pages to back the testing guest memory. In order to add flexibility, now list all the known hugetlb backing src types with different page sizes, so that we can specify use of hugetlb pages of the exact granularity that we want. And as all the known hugetlb page sizes are listed, it's appropriate for all architectures.

Besides, the helper get_backing_src_pagesz() is added to get the granularity of different backing src types(anonumous, thp, hugetlb).

Suggested-by: Ben Gardon bgardon@google.com Signed-off-by: Yanan Wang wangyanan55@huawei.com Reviewed-by: Andrew Jones drjones@redhat.com --- .../testing/selftests/kvm/include/test_util.h | 18 ++- tools/testing/selftests/kvm/lib/kvm_util.c | 2 +- tools/testing/selftests/kvm/lib/test_util.c | 109 ++++++++++++++++-- 3 files changed, 116 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index e087174eefe5..fade3130eb01 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -71,16 +71,32 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS, VM_MEM_SRC_ANONYMOUS_THP, VM_MEM_SRC_ANONYMOUS_HUGETLB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_16KB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_64KB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_512KB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_1MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_2MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_8MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_16MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_32MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_256MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_512MB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB, + VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, + NUM_SRC_TYPES, };

struct vm_mem_backing_src_alias { const char *name; - enum vm_mem_backing_src_type type; + uint32_t flag; };

bool thp_configured(void); size_t get_trans_hugepagesz(void); size_t get_def_hugetlb_pagesz(void); +const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i); +size_t get_backing_src_pagesz(uint32_t i); void backing_src_help(void); enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name);

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 2ea837fe03af..3506174c2053 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -759,7 +759,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, region->mmap_start = mmap(NULL, region->mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS - | (src_type == VM_MEM_SRC_ANONYMOUS_HUGETLB ? MAP_HUGETLB : 0), + | vm_mem_backing_src_alias(src_type)->flag, -1, 0); TEST_ASSERT(region->mmap_start != MAP_FAILED, "test_malloc failed, mmap_start: %p errno: %i", diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index 665724ccab97..205408bffa38 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -11,6 +11,7 @@ #include <stdlib.h> #include <time.h> #include <sys/stat.h> +#include <linux/mman.h> #include "linux/kernel.h"

#include "test_util.h" @@ -112,12 +113,6 @@ void print_skip(const char *fmt, ...) puts(", skipping test"); }

-const struct vm_mem_backing_src_alias backing_src_aliases[] = { - {"anonymous", VM_MEM_SRC_ANONYMOUS,}, - {"anonymous_thp", VM_MEM_SRC_ANONYMOUS_THP,}, - {"anonymous_hugetlb", VM_MEM_SRC_ANONYMOUS_HUGETLB,}, -}; - bool thp_configured(void) { int ret; @@ -171,22 +166,114 @@ size_t get_def_hugetlb_pagesz(void) return 0; }

+const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i) +{ + static const struct vm_mem_backing_src_alias aliases[] = { + [VM_MEM_SRC_ANONYMOUS] = { + .name = "anonymous", + .flag = 0, + }, + [VM_MEM_SRC_ANONYMOUS_THP] = { + .name = "anonymous_thp", + .flag = 0, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB] = { + .name = "anonymous_hugetlb", + .flag = MAP_HUGETLB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_16KB] = { + .name = "anonymous_hugetlb_16kb", + .flag = MAP_HUGETLB | MAP_HUGE_16KB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_64KB] = { + .name = "anonymous_hugetlb_64kb", + .flag = MAP_HUGETLB | MAP_HUGE_64KB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_512KB] = { + .name = "anonymous_hugetlb_512kb", + .flag = MAP_HUGETLB | MAP_HUGE_512KB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_1MB] = { + .name = "anonymous_hugetlb_1mb", + .flag = MAP_HUGETLB | MAP_HUGE_1MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_2MB] = { + .name = "anonymous_hugetlb_2mb", + .flag = MAP_HUGETLB | MAP_HUGE_2MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_8MB] = { + .name = "anonymous_hugetlb_8mb", + .flag = MAP_HUGETLB | MAP_HUGE_8MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_16MB] = { + .name = "anonymous_hugetlb_16mb", + .flag = MAP_HUGETLB | MAP_HUGE_16MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_32MB] = { + .name = "anonymous_hugetlb_32mb", + .flag = MAP_HUGETLB | MAP_HUGE_32MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_256MB] = { + .name = "anonymous_hugetlb_256mb", + .flag = MAP_HUGETLB | MAP_HUGE_256MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_512MB] = { + .name = "anonymous_hugetlb_512mb", + .flag = MAP_HUGETLB | MAP_HUGE_512MB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB] = { + .name = "anonymous_hugetlb_1gb", + .flag = MAP_HUGETLB | MAP_HUGE_1GB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB] = { + .name = "anonymous_hugetlb_2gb", + .flag = MAP_HUGETLB | MAP_HUGE_2GB, + }, + [VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB] = { + .name = "anonymous_hugetlb_16gb", + .flag = MAP_HUGETLB | MAP_HUGE_16GB, + }, + }; + _Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES, + "Missing new backing src types?"); + + TEST_ASSERT(i < NUM_SRC_TYPES, "Backing src type ID %d too big", i); + + return &aliases[i]; +} + +size_t get_backing_src_pagesz(uint32_t i) +{ + uint32_t flag = vm_mem_backing_src_alias(i)->flag; + + switch (i) { + case VM_MEM_SRC_ANONYMOUS: + return getpagesize(); + case VM_MEM_SRC_ANONYMOUS_THP: + return get_trans_hugepagesz(); + case VM_MEM_SRC_ANONYMOUS_HUGETLB: + return get_def_hugetlb_pagesz(); + default: + return MAP_HUGE_PAGE_SIZE(flag); + } +} + void backing_src_help(void) { int i;

printf("Available backing src types:\n"); - for (i = 0; i < ARRAY_SIZE(backing_src_aliases); i++) - printf("\t%s\n", backing_src_aliases[i].name); + for (i = 0; i < NUM_SRC_TYPES; i++) + printf("\t%s\n", vm_mem_backing_src_alias(i)->name); }

enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name) { int i;

- for (i = 0; i < ARRAY_SIZE(backing_src_aliases); i++) - if (!strcmp(type_name, backing_src_aliases[i].name)) - return backing_src_aliases[i].type; + for (i = 0; i < NUM_SRC_TYPES; i++) + if (!strcmp(type_name, vm_mem_backing_src_alias(i)->name)) + return i;

backing_src_help(); TEST_FAIL("Unknown backing src type: %s", type_name);

This test serves as a performance tester and a bug reproducer for kvm page table code (GPA->HPA mappings), so it gives guidance for people trying to make some improvement for kvm.

The function guest_code() can cover the conditions where a single vcpu or multiple vcpus access guest pages within the same memory region, in three VM stages(before dirty logging, during dirty logging, after dirty logging). Besides, the backing src memory type(ANONYMOUS/THP/HUGETLB) of the tested memory region can be specified by users, which means normal page mappings or block mappings can be chosen by users to be created in the test.

If ANONYMOUS memory is specified, kvm will create normal page mappings for the tested memory region before dirty logging, and update attributes of the page mappings from RO to RW during dirty logging. If THP/HUGETLB memory is specified, kvm will create block mappings for the tested memory region before dirty logging, and split the blcok mappings into normal page mappings during dirty logging, and coalesce the page mappings back into block mappings after dirty logging is stopped.

So in summary, as a performance tester, this test can present the performance of kvm creating/updating normal page mappings, or the performance of kvm creating/splitting/recovering block mappings, through execution time.

When we need to coalesce the page mappings back to block mappings after dirty logging is stopped, we have to firstly invalidate *all* the TLB entries for the page mappings right before installation of the block entry, because a TLB conflict abort error could occur if we can't invalidate the TLB entries fully. We have hit this TLB conflict twice on aarch64 software implementation and fixed it. As this test can imulate process from dirty logging enabled to dirty logging stopped of a VM with block mappings, so it can also reproduce this TLB conflict abort due to inadequate TLB invalidation when coalescing tables.

Signed-off-by: Yanan Wang wangyanan55@huawei.com Reviewed-by: Ben Gardon bgardon@google.com Reviewed-by: Andrew Jones drjones@redhat.com --- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 3 + .../selftests/kvm/kvm_page_table_test.c | 506 ++++++++++++++++++ 3 files changed, 510 insertions(+) create mode 100644 tools/testing/selftests/kvm/kvm_page_table_test.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 32b87cc77c8e..137ab7273be6 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -35,6 +35,7 @@ /dirty_log_perf_test /hardware_disable_test /kvm_create_max_vcpus +/kvm_page_table_test /memslot_modification_stress_test /set_memory_region_test /steal_time diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index a6d61f451f88..75dc57db36b4 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -69,6 +69,7 @@ TEST_GEN_PROGS_x86_64 += dirty_log_test TEST_GEN_PROGS_x86_64 += dirty_log_perf_test TEST_GEN_PROGS_x86_64 += hardware_disable_test TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus +TEST_GEN_PROGS_x86_64 += kvm_page_table_test TEST_GEN_PROGS_x86_64 += memslot_modification_stress_test TEST_GEN_PROGS_x86_64 += set_memory_region_test TEST_GEN_PROGS_x86_64 += steal_time @@ -79,6 +80,7 @@ TEST_GEN_PROGS_aarch64 += demand_paging_test TEST_GEN_PROGS_aarch64 += dirty_log_test TEST_GEN_PROGS_aarch64 += dirty_log_perf_test TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus +TEST_GEN_PROGS_aarch64 += kvm_page_table_test TEST_GEN_PROGS_aarch64 += set_memory_region_test TEST_GEN_PROGS_aarch64 += steal_time

@@ -88,6 +90,7 @@ TEST_GEN_PROGS_s390x += s390x/sync_regs_test TEST_GEN_PROGS_s390x += demand_paging_test TEST_GEN_PROGS_s390x += dirty_log_test TEST_GEN_PROGS_s390x += kvm_create_max_vcpus +TEST_GEN_PROGS_s390x += kvm_page_table_test TEST_GEN_PROGS_s390x += set_memory_region_test

TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M)) diff --git a/tools/testing/selftests/kvm/kvm_page_table_test.c b/tools/testing/selftests/kvm/kvm_page_table_test.c new file mode 100644 index 000000000000..1c4753fff19e --- /dev/null +++ b/tools/testing/selftests/kvm/kvm_page_table_test.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KVM page table test + * + * Copyright (C) 2021, Huawei, Inc. + * + * Make sure that THP has been enabled or enough HUGETLB pages with specific + * page size have been pre-allocated on your system, if you are planning to + * use hugepages to back the guest memory for testing. + */ + +#define _GNU_SOURCE /* for program_invocation_name */ + +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <pthread.h> +#include <semaphore.h> + +#include "test_util.h" +#include "kvm_util.h" +#include "processor.h" +#include "guest_modes.h" + +#define TEST_MEM_SLOT_INDEX 1 + +/* Default size(1GB) of the memory for testing */ +#define DEFAULT_TEST_MEM_SIZE (1 << 30) + +/* Default guest test virtual memory offset */ +#define DEFAULT_GUEST_TEST_MEM 0xc0000000 + +/* Different guest memory accessing stages */ +enum test_stage { + KVM_BEFORE_MAPPINGS, + KVM_CREATE_MAPPINGS, + KVM_UPDATE_MAPPINGS, + KVM_ADJUST_MAPPINGS, + NUM_TEST_STAGES, +}; + +static const char * const test_stage_string[] = { + "KVM_BEFORE_MAPPINGS", + "KVM_CREATE_MAPPINGS", + "KVM_UPDATE_MAPPINGS", + "KVM_ADJUST_MAPPINGS", +}; + +struct vcpu_args { + int vcpu_id; + bool vcpu_write; +}; + +struct test_args { + struct kvm_vm *vm; + uint64_t guest_test_virt_mem; + uint64_t host_page_size; + uint64_t host_num_pages; + uint64_t large_page_size; + uint64_t large_num_pages; + uint64_t host_pages_per_lpage; + enum vm_mem_backing_src_type src_type; + struct vcpu_args vcpu_args[KVM_MAX_VCPUS]; +}; + +/* + * Guest variables. Use addr_gva2hva() if these variables need + * to be changed in host. + */ +static enum test_stage guest_test_stage; + +/* Host variables */ +static uint32_t nr_vcpus = 1; +static struct test_args test_args; +static enum test_stage *current_stage; +static bool host_quit; + +/* Whether the test stage is updated, or completed */ +static sem_t test_stage_updated; +static sem_t test_stage_completed; + +/* + * Guest physical memory offset of the testing memory slot. + * This will be set to the topmost valid physical address minus + * the test memory size. + */ +static uint64_t guest_test_phys_mem; + +/* + * Guest virtual memory offset of the testing memory slot. + * Must not conflict with identity mapped test code. + */ +static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; + +static void guest_code(int vcpu_id) +{ + struct test_args *p = &test_args; + struct vcpu_args *vcpu_args = &p->vcpu_args[vcpu_id]; + enum test_stage *current_stage = &guest_test_stage; + uint64_t addr; + int i, j; + + /* Make sure vCPU args data structure is not corrupt */ + GUEST_ASSERT(vcpu_args->vcpu_id == vcpu_id); + + while (true) { + addr = p->guest_test_virt_mem; + + switch (READ_ONCE(*current_stage)) { + /* + * All vCPU threads will be started in this stage, + * where guest code of each vCPU will do nothing. + */ + case KVM_BEFORE_MAPPINGS: + break; + + /* + * Before dirty logging, vCPUs concurrently access the first + * 8 bytes of each page (host page/large page) within the same + * memory region with different accessing types (read/write). + * Then KVM will create normal page mappings or huge block + * mappings for them. + */ + case KVM_CREATE_MAPPINGS: + for (i = 0; i < p->large_num_pages; i++) { + if (vcpu_args->vcpu_write) + *(uint64_t *)addr = 0x0123456789ABCDEF; + else + READ_ONCE(*(uint64_t *)addr); + + addr += p->large_page_size; + } + break; + + /* + * During dirty logging, KVM will only update attributes of the + * normal page mappings from RO to RW if memory backing src type + * is anonymous. In other cases, KVM will split the huge block + * mappings into normal page mappings if memory backing src type + * is THP or HUGETLB. + */ + case KVM_UPDATE_MAPPINGS: + if (p->src_type == VM_MEM_SRC_ANONYMOUS) { + for (i = 0; i < p->host_num_pages; i++) { + *(uint64_t *)addr = 0x0123456789ABCDEF; + addr += p->host_page_size; + } + break; + } + + for (i = 0; i < p->large_num_pages; i++) { + /* + * Write to the first host page in each large + * page region, and triger break of large pages. + */ + *(uint64_t *)addr = 0x0123456789ABCDEF; + + /* + * Access the middle host pages in each large + * page region. Since dirty logging is enabled, + * this will create new mappings at the smallest + * granularity. + */ + addr += p->large_page_size / 2; + for (j = 0; j < p->host_pages_per_lpage / 2; j++) { + READ_ONCE(*(uint64_t *)addr); + addr += p->host_page_size; + } + } + break; + + /* + * After dirty logging is stopped, vCPUs concurrently read + * from every single host page. Then KVM will coalesce the + * split page mappings back to block mappings. And a TLB + * conflict abort could occur here if TLB entries of the + * page mappings are not fully invalidated. + */ + case KVM_ADJUST_MAPPINGS: + for (i = 0; i < p->host_num_pages; i++) { + READ_ONCE(*(uint64_t *)addr); + addr += p->host_page_size; + } + break; + + default: + GUEST_ASSERT(0); + } + + GUEST_SYNC(1); + } +} + +static void *vcpu_worker(void *data) +{ + int ret; + struct vcpu_args *vcpu_args = data; + struct kvm_vm *vm = test_args.vm; + int vcpu_id = vcpu_args->vcpu_id; + struct kvm_run *run; + struct timespec start; + struct timespec ts_diff; + enum test_stage stage; + + vcpu_args_set(vm, vcpu_id, 1, vcpu_id); + run = vcpu_state(vm, vcpu_id); + + while (!READ_ONCE(host_quit)) { + ret = sem_wait(&test_stage_updated); + TEST_ASSERT(ret == 0, "Error in sem_wait"); + + if (READ_ONCE(host_quit)) + return NULL; + + clock_gettime(CLOCK_MONOTONIC_RAW, &start); + ret = _vcpu_run(vm, vcpu_id); + ts_diff = timespec_elapsed(start); + + TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); + TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC, + "Invalid guest sync status: exit_reason=%s\n", + exit_reason_str(run->exit_reason)); + + pr_debug("Got sync event from vCPU %d\n", vcpu_id); + stage = READ_ONCE(*current_stage); + + /* + * Here we can know the execution time of every + * single vcpu running in different test stages. + */ + pr_debug("vCPU %d has completed stage %s\n" + "execution time is: %ld.%.9lds\n\n", + vcpu_id, test_stage_string[stage], + ts_diff.tv_sec, ts_diff.tv_nsec); + + ret = sem_post(&test_stage_completed); + TEST_ASSERT(ret == 0, "Error in sem_post"); + } + + return NULL; +} + +struct test_params { + uint64_t phys_offset; + uint64_t test_mem_size; + enum vm_mem_backing_src_type src_type; +}; + +static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg) +{ + int ret; + struct test_params *p = arg; + struct vcpu_args *vcpu_args; + enum vm_mem_backing_src_type src_type = p->src_type; + uint64_t large_page_size = get_backing_src_pagesz(src_type); + uint64_t guest_page_size = vm_guest_mode_params[mode].page_size; + uint64_t host_page_size = getpagesize(); + uint64_t test_mem_size = p->test_mem_size; + uint64_t guest_num_pages; + uint64_t alignment; + void *host_test_mem; + struct kvm_vm *vm; + int vcpu_id; + + /* Align up the test memory size */ + alignment = max(large_page_size, guest_page_size); + test_mem_size = (test_mem_size + alignment - 1) & ~(alignment - 1); + + /* Create a VM with enough guest pages */ + guest_num_pages = test_mem_size / guest_page_size; + vm = vm_create_with_vcpus(mode, nr_vcpus, + guest_num_pages, 0, guest_code, NULL); + + /* Align down GPA of the testing memslot */ + if (!p->phys_offset) + guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) * + guest_page_size; + else + guest_test_phys_mem = p->phys_offset; +#ifdef __s390x__ + alignment = max(0x100000, alignment); +#endif + guest_test_phys_mem &= ~(alignment - 1); + + /* Set up the shared data structure test_args */ + test_args.vm = vm; + test_args.guest_test_virt_mem = guest_test_virt_mem; + test_args.host_page_size = host_page_size; + test_args.host_num_pages = test_mem_size / host_page_size; + test_args.large_page_size = large_page_size; + test_args.large_num_pages = test_mem_size / large_page_size; + test_args.host_pages_per_lpage = large_page_size / host_page_size; + test_args.src_type = src_type; + + for (vcpu_id = 0; vcpu_id < KVM_MAX_VCPUS; vcpu_id++) { + vcpu_args = &test_args.vcpu_args[vcpu_id]; + vcpu_args->vcpu_id = vcpu_id; + vcpu_args->vcpu_write = !(vcpu_id % 2); + } + + /* Add an extra memory slot with specified backing src type */ + vm_userspace_mem_region_add(vm, src_type, guest_test_phys_mem, + TEST_MEM_SLOT_INDEX, guest_num_pages, 0); + + /* Do mapping(GVA->GPA) for the testing memory slot */ + virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0); + + /* Cache the HVA pointer of the region */ + host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); + + /* Export shared structure test_args to guest */ + ucall_init(vm, NULL); + sync_global_to_guest(vm, test_args); + + ret = sem_init(&test_stage_updated, 0, 0); + TEST_ASSERT(ret == 0, "Error in sem_init"); + + ret = sem_init(&test_stage_completed, 0, 0); + TEST_ASSERT(ret == 0, "Error in sem_init"); + + current_stage = addr_gva2hva(vm, (vm_vaddr_t)(&guest_test_stage)); + *current_stage = NUM_TEST_STAGES; + + pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); + pr_info("Testing memory backing src type: %s\n", + vm_mem_backing_src_alias(src_type)->name); + pr_info("Testing memory backing src granularity: 0x%lx\n", + large_page_size); + pr_info("Testing memory size(aligned): 0x%lx\n", test_mem_size); + pr_info("Guest physical test memory offset: 0x%lx\n", + guest_test_phys_mem); + pr_info("Host virtual test memory offset: 0x%lx\n", + (uint64_t)host_test_mem); + pr_info("Number of testing vCPUs: %d\n", nr_vcpus); + + return vm; +} + +static void vcpus_complete_new_stage(enum test_stage stage) +{ + int ret; + int vcpus; + + /* Wake up all the vcpus to run new test stage */ + for (vcpus = 0; vcpus < nr_vcpus; vcpus++) { + ret = sem_post(&test_stage_updated); + TEST_ASSERT(ret == 0, "Error in sem_post"); + } + pr_debug("All vcpus have been notified to continue\n"); + + /* Wait for all the vcpus to complete new test stage */ + for (vcpus = 0; vcpus < nr_vcpus; vcpus++) { + ret = sem_wait(&test_stage_completed); + TEST_ASSERT(ret == 0, "Error in sem_wait"); + + pr_debug("%d vcpus have completed stage %s\n", + vcpus + 1, test_stage_string[stage]); + } + + pr_debug("All vcpus have completed stage %s\n", + test_stage_string[stage]); +} + +static void run_test(enum vm_guest_mode mode, void *arg) +{ + int ret; + pthread_t *vcpu_threads; + struct kvm_vm *vm; + int vcpu_id; + struct timespec start; + struct timespec ts_diff; + + /* Create VM with vCPUs and make some pre-initialization */ + vm = pre_init_before_test(mode, arg); + + vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads)); + TEST_ASSERT(vcpu_threads, "Memory allocation failed"); + + host_quit = false; + *current_stage = KVM_BEFORE_MAPPINGS; + + for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { + pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker, + &test_args.vcpu_args[vcpu_id]); + } + + vcpus_complete_new_stage(*current_stage); + pr_info("Started all vCPUs successfully\n"); + + /* Test the stage of KVM creating mappings */ + *current_stage = KVM_CREATE_MAPPINGS; + + clock_gettime(CLOCK_MONOTONIC_RAW, &start); + vcpus_complete_new_stage(*current_stage); + ts_diff = timespec_elapsed(start); + + pr_info("KVM_CREATE_MAPPINGS: total execution time: %ld.%.9lds\n\n", + ts_diff.tv_sec, ts_diff.tv_nsec); + + /* Test the stage of KVM updating mappings */ + vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, + KVM_MEM_LOG_DIRTY_PAGES); + + *current_stage = KVM_UPDATE_MAPPINGS; + + clock_gettime(CLOCK_MONOTONIC_RAW, &start); + vcpus_complete_new_stage(*current_stage); + ts_diff = timespec_elapsed(start); + + pr_info("KVM_UPDATE_MAPPINGS: total execution time: %ld.%.9lds\n\n", + ts_diff.tv_sec, ts_diff.tv_nsec); + + /* Test the stage of KVM adjusting mappings */ + vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 0); + + *current_stage = KVM_ADJUST_MAPPINGS; + + clock_gettime(CLOCK_MONOTONIC_RAW, &start); + vcpus_complete_new_stage(*current_stage); + ts_diff = timespec_elapsed(start); + + pr_info("KVM_ADJUST_MAPPINGS: total execution time: %ld.%.9lds\n\n", + ts_diff.tv_sec, ts_diff.tv_nsec); + + /* Tell the vcpu thread to quit */ + host_quit = true; + for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { + ret = sem_post(&test_stage_updated); + TEST_ASSERT(ret == 0, "Error in sem_post"); + } + + for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) + pthread_join(vcpu_threads[vcpu_id], NULL); + + ret = sem_destroy(&test_stage_updated); + TEST_ASSERT(ret == 0, "Error in sem_destroy"); + + ret = sem_destroy(&test_stage_completed); + TEST_ASSERT(ret == 0, "Error in sem_destroy"); + + free(vcpu_threads); + ucall_uninit(vm); + kvm_vm_free(vm); +} + +static void help(char *name) +{ + puts(""); + printf("usage: %s [-h] [-p offset] [-m mode] " + "[-b mem-size] [-v vcpus] [-s mem-type]\n", name); + puts(""); + printf(" -p: specify guest physical test memory offset\n" + " Warning: a low offset can conflict with the loaded test code.\n"); + guest_modes_help(); + printf(" -b: specify size of the memory region for testing. e.g. 10M or 3G.\n" + " (default: 1G)\n"); + printf(" -v: specify the number of vCPUs to run\n" + " (default: 1)\n"); + printf(" -s: specify the type of memory that should be used to\n" + " back the guest data region.\n" + " (default: anonymous)\n\n"); + backing_src_help(); + puts(""); +} + +int main(int argc, char *argv[]) +{ + int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); + struct test_params p = { + .test_mem_size = DEFAULT_TEST_MEM_SIZE, + .src_type = VM_MEM_SRC_ANONYMOUS, + }; + int opt; + + guest_modes_append_default(); + + while ((opt = getopt(argc, argv, "hp:m:b:v:s:")) != -1) { + switch (opt) { + case 'p': + p.phys_offset = strtoull(optarg, NULL, 0); + break; + case 'm': + guest_modes_cmdline(optarg); + break; + case 'b': + p.test_mem_size = parse_size(optarg); + break; + case 'v': + nr_vcpus = atoi(optarg); + TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, + "Invalid number of vcpus, must be between 1 and %d", max_vcpus); + break; + case 's': + p.src_type = parse_backing_src_type(optarg); + break; + case 'h': + default: + help(argv[0]); + exit(0); + } + } + + for_each_guest_mode(run_test, &p); + + return 0; +}