Hi,
This v5 series can mainly include two parts.
Based on kvm queue branch: https://git.kernel.org/pub/scm/virt/kvm/kvm.git/log/?h=queue
In the first part, all the known hugetlb backing src types specified
with different hugepage sizes are listed, so that we can specify use
of hugetlb source of the exact granularity that we want, instead of
the system default ones. And as all the known hugetlb page sizes are
listed, it's appropriate for all architectures. Besides, a helper that
can get granularity of different backing src types(anonumous/thp/hugetlb)
is added, so that we can use the accurate backing src granularity for
kinds of alignment or guest memory accessing of vcpus.
In the second part, a new test is added:
This test is added to serve as a performance tester and a bug reproducer
for kvm page table code (GPA->HPA mappings), it gives guidance for the
people trying to make some improvement for kvm. And the following explains
what we can exactly do through this test.
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.
Links about the TLB conflict abort:
https://lore.kernel.org/lkml/[email protected]/
---
Change logs:
v4->v5:
- Use synchronization(sem_wait) for time measurement
- Add a new patch about TEST_ASSERT(patch 4)
- Address Andrew Jones's comments for v4 series
- Add Andrew Jones's R-b tags in some patches
- v4: https://lore.kernel.org/lkml/[email protected]/
v3->v4:
- Add a helper to get system default hugetlb page size
- Add tags of Reviewed-by of Ben in the patches
- v3: https://lore.kernel.org/lkml/[email protected]/
v2->v3:
- Add tags of Suggested-by, Reviewed-by in the patches
- Add a generic micro to get hugetlb page sizes
- Some changes for suggestions about v2 series
- v2: https://lore.kernel.org/lkml/[email protected]/
v1->v2:
- Add a patch to sync header files
- Add helpers to get granularity of different backing src types
- Some changes for suggestions about v1 series
- v1: https://lore.kernel.org/lkml/[email protected]/
---
Yanan Wang (10):
tools headers: sync headers of asm-generic/hugetlb_encode.h
tools headers: Add a macro to get HUGETLB page sizes for mmap
KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing
KVM: selftests: Print the errno besides error-string in TEST_ASSERT
KVM: selftests: Make a generic helper to get vm guest mode strings
KVM: selftests: Add a helper to get system configured THP page size
KVM: selftests: Add a helper to get system default hugetlb page size
KVM: selftests: List all hugetlb src types specified with page sizes
KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers
KVM: selftests: Add a test for kvm page table code
include/uapi/linux/mman.h | 2 +
tools/include/asm-generic/hugetlb_encode.h | 3 +
tools/include/uapi/linux/mman.h | 2 +
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 3 +
.../selftests/kvm/demand_paging_test.c | 8 +-
.../selftests/kvm/dirty_log_perf_test.c | 14 +-
.../testing/selftests/kvm/include/kvm_util.h | 4 +-
.../testing/selftests/kvm/include/test_util.h | 21 +-
.../selftests/kvm/kvm_page_table_test.c | 512 ++++++++++++++++++
tools/testing/selftests/kvm/lib/assert.c | 4 +-
tools/testing/selftests/kvm/lib/kvm_util.c | 59 +-
tools/testing/selftests/kvm/lib/test_util.c | 163 +++++-
tools/testing/selftests/kvm/steal_time.c | 4 +-
14 files changed, 739 insertions(+), 61 deletions(-)
create mode 100644 tools/testing/selftests/kvm/kvm_page_table_test.c
--
2.23.0
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 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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Suggested-by: Ben Gardon <[email protected]>
Signed-off-by: Yanan Wang <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>
---
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 */
--
2.19.1
For generality and conciseness, make an API which can be used in all
kvm libs and selftests to get vm guest mode strings. And the index i
is checked in the API in case of possiable faults.
Suggested-by: Sean Christopherson <[email protected]>
Signed-off-by: Yanan Wang <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>
---
.../testing/selftests/kvm/include/kvm_util.h | 4 +--
tools/testing/selftests/kvm/lib/kvm_util.c | 29 ++++++++++++-------
2 files changed, 19 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 2d7eb6989e83..f52a7492f47f 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -68,9 +68,6 @@ enum vm_guest_mode {
#define MIN_PAGE_SIZE (1U << MIN_PAGE_SHIFT)
#define PTES_PER_MIN_PAGE ptes_per_page(MIN_PAGE_SIZE)
-#define vm_guest_mode_string(m) vm_guest_mode_string[m]
-extern const char * const vm_guest_mode_string[];
-
struct vm_guest_mode_params {
unsigned int pa_bits;
unsigned int va_bits;
@@ -84,6 +81,7 @@ int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap);
int vcpu_enable_cap(struct kvm_vm *vm, uint32_t vcpu_id,
struct kvm_enable_cap *cap);
void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size);
+const char *vm_guest_mode_string(uint32_t i);
struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
void kvm_vm_free(struct kvm_vm *vmp);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index e5fbf16f725b..2ea837fe03af 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -143,17 +143,24 @@ static void vm_open(struct kvm_vm *vm, int perm)
"rc: %i errno: %i", vm->fd, errno);
}
-const char * const vm_guest_mode_string[] = {
- "PA-bits:52, VA-bits:48, 4K pages",
- "PA-bits:52, VA-bits:48, 64K pages",
- "PA-bits:48, VA-bits:48, 4K pages",
- "PA-bits:48, VA-bits:48, 64K pages",
- "PA-bits:40, VA-bits:48, 4K pages",
- "PA-bits:40, VA-bits:48, 64K pages",
- "PA-bits:ANY, VA-bits:48, 4K pages",
-};
-_Static_assert(sizeof(vm_guest_mode_string)/sizeof(char *) == NUM_VM_MODES,
- "Missing new mode strings?");
+const char *vm_guest_mode_string(uint32_t i)
+{
+ static const char * const strings[] = {
+ [VM_MODE_P52V48_4K] = "PA-bits:52, VA-bits:48, 4K pages",
+ [VM_MODE_P52V48_64K] = "PA-bits:52, VA-bits:48, 64K pages",
+ [VM_MODE_P48V48_4K] = "PA-bits:48, VA-bits:48, 4K pages",
+ [VM_MODE_P48V48_64K] = "PA-bits:48, VA-bits:48, 64K pages",
+ [VM_MODE_P40V48_4K] = "PA-bits:40, VA-bits:48, 4K pages",
+ [VM_MODE_P40V48_64K] = "PA-bits:40, VA-bits:48, 64K pages",
+ [VM_MODE_PXXV48_4K] = "PA-bits:ANY, VA-bits:48, 4K pages",
+ };
+ _Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
+ "Missing new mode strings?");
+
+ TEST_ASSERT(i < NUM_VM_MODES, "Guest mode ID %d too big", i);
+
+ return strings[i];
+}
const struct vm_guest_mode_params vm_guest_mode_params[] = {
{ 52, 48, 0x1000, 12 },
--
2.19.1
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 <[email protected]>
Signed-off-by: Yanan Wang <[email protected]>
---
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);
--
2.19.1
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 <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>
---
.../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;
--
2.19.1
With VM_MEM_SRC_ANONYMOUS_THP specified in vm_userspace_mem_region_add(),
we have to get the transparent hugepage size for HVA alignment. With the
new helpers, we can use get_backing_src_pagesz() to check whether THP is
configured and then get the exact configured hugepage size.
As different architectures may have different THP page sizes configured,
this can get the accurate THP page sizes on any platform.
Signed-off-by: Yanan Wang <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
---
tools/testing/selftests/kvm/lib/kvm_util.c | 28 +++++++---------------
1 file changed, 9 insertions(+), 19 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 3506174c2053..c7a2228deaf3 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -18,7 +18,6 @@
#include <unistd.h>
#include <linux/kernel.h>
-#define KVM_UTIL_PGS_PER_HUGEPG 512
#define KVM_UTIL_MIN_PFN 2
static int vcpu_mmap_sz(void);
@@ -688,7 +687,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
{
int ret;
struct userspace_mem_region *region;
- size_t huge_page_size = KVM_UTIL_PGS_PER_HUGEPG * vm->page_size;
+ size_t backing_src_pagesz = get_backing_src_pagesz(src_type);
size_t alignment;
TEST_ASSERT(vm_adjust_num_guest_pages(vm->mode, npages) == npages,
@@ -750,7 +749,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
#endif
if (src_type == VM_MEM_SRC_ANONYMOUS_THP)
- alignment = max(huge_page_size, alignment);
+ alignment = max(backing_src_pagesz, alignment);
/* Add enough memory to align up if necessary */
if (alignment > 1)
@@ -769,22 +768,13 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
region->host_mem = align(region->mmap_start, alignment);
/* As needed perform madvise */
- if (src_type == VM_MEM_SRC_ANONYMOUS || src_type == VM_MEM_SRC_ANONYMOUS_THP) {
- struct stat statbuf;
-
- ret = stat("/sys/kernel/mm/transparent_hugepage", &statbuf);
- TEST_ASSERT(ret == 0 || (ret == -1 && errno == ENOENT),
- "stat /sys/kernel/mm/transparent_hugepage");
-
- TEST_ASSERT(ret == 0 || src_type != VM_MEM_SRC_ANONYMOUS_THP,
- "VM_MEM_SRC_ANONYMOUS_THP requires THP to be configured in the host kernel");
-
- if (ret == 0) {
- ret = madvise(region->host_mem, npages * vm->page_size,
- src_type == VM_MEM_SRC_ANONYMOUS ? MADV_NOHUGEPAGE : MADV_HUGEPAGE);
- TEST_ASSERT(ret == 0, "madvise failed, addr: %p length: 0x%lx src_type: %x",
- region->host_mem, npages * vm->page_size, src_type);
- }
+ if ((src_type == VM_MEM_SRC_ANONYMOUS ||
+ src_type == VM_MEM_SRC_ANONYMOUS_THP) && thp_configured()) {
+ ret = madvise(region->host_mem, npages * vm->page_size,
+ src_type == VM_MEM_SRC_ANONYMOUS ? MADV_NOHUGEPAGE : MADV_HUGEPAGE);
+ TEST_ASSERT(ret == 0, "madvise failed, addr: %p length: 0x%lx src_type: %s",
+ region->host_mem, npages * vm->page_size,
+ vm_mem_backing_src_alias(src_type)->name);
}
region->unused_phy_pages = sparsebit_alloc();
--
2.19.1
If HUGETLB is configured in the host kernel, then we can know the system
default hugetlb page size through *cat /proc/meminfo*. Otherwise, we will
not see the information of hugetlb pages in file /proc/meminfo if it's not
configured. So add a helper to determine whether HUGETLB is configured and
then get the default page size by reading /proc/meminfo.
This helper can be useful when a program wants to use the default hugetlb
pages of the system and doesn't know the default page size.
Signed-off-by: Yanan Wang <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
---
.../testing/selftests/kvm/include/test_util.h | 1 +
tools/testing/selftests/kvm/lib/test_util.c | 25 +++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
index ef24c76ba89a..e087174eefe5 100644
--- a/tools/testing/selftests/kvm/include/test_util.h
+++ b/tools/testing/selftests/kvm/include/test_util.h
@@ -80,6 +80,7 @@ struct vm_mem_backing_src_alias {
bool thp_configured(void);
size_t get_trans_hugepagesz(void);
+size_t get_def_hugetlb_pagesz(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 efc1a7782de0..665724ccab97 100644
--- a/tools/testing/selftests/kvm/lib/test_util.c
+++ b/tools/testing/selftests/kvm/lib/test_util.c
@@ -146,6 +146,31 @@ size_t get_trans_hugepagesz(void)
return size;
}
+size_t get_def_hugetlb_pagesz(void)
+{
+ char buf[64];
+ const char *tag = "Hugepagesize:";
+ FILE *f;
+
+ f = fopen("/proc/meminfo", "r");
+ TEST_ASSERT(f != NULL, "Error in opening /proc/meminfo");
+
+ while (fgets(buf, sizeof(buf), f) != NULL) {
+ if (strstr(buf, tag) == buf) {
+ fclose(f);
+ return strtoull(buf + strlen(tag), NULL, 10) << 10;
+ }
+ }
+
+ if (feof(f))
+ TEST_FAIL("HUGETLB is not configured in host kernel");
+ else
+ TEST_FAIL("Error in reading /proc/meminfo");
+
+ fclose(f);
+ return 0;
+}
+
void backing_src_help(void)
{
int i;
--
2.19.1
On Tue, Mar 23, 2021 at 09:52:25PM +0800, Yanan Wang wrote:
> 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 <[email protected]>
> Signed-off-by: Yanan Wang <[email protected]>
> ---
> 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);
> --
> 2.19.1
>
Reviewed-by: Andrew Jones <[email protected]>
On Tue, Mar 23, 2021 at 09:52:27PM +0800, Yanan Wang wrote:
> 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 <[email protected]>
> Reviewed-by: Ben Gardon <[email protected]>
> ---
> .../testing/selftests/kvm/include/test_util.h | 2 ++
> tools/testing/selftests/kvm/lib/test_util.c | 29 +++++++++++++++++++
> 2 files changed, 31 insertions(+)
Reviewed-by: Andrew Jones <[email protected]>