KVM: selftests: Define _GNU_SOURCE for all selftests code

Define _GNU_SOURCE is the base CFLAGS instead of relying on selftests to
manually #define _GNU_SOURCE, which is repetitive and error prone.

KVM: selftests: Define _GNU_SOURCE for all selftests code

Define _GNU_SOURCE is the base CFLAGS instead of relying on selftests to
manually #define _GNU_SOURCE, which is repetitive and error prone. E.g.
kselftest_harness.h requires _GNU_SOURCE for asprintf(), but if a selftest
includes kvm_test_harness.h after stdio.h, the include guards result in
the effective version of stdio.h consumed by kvm_test_harness.h not
defining asprintf():

In file included from x86_64/fix_hypercall_test.c:12:
In file included from include/kvm_test_harness.h:11:
../kselftest_harness.h:1169:2: error: call to undeclared function
'asprintf'; ISO C99 and later do not support implicit function declarations
[-Wimplicit-function-declaration]
1169 | asprintf(&test_name, "%s%s%s.%s", f->name,
| ^

When including the rseq selftest's "library" code, #undef _GNU_SOURCE so
that rseq.c controls whether or not it wants to build with _GNU_SOURCE.

Reported-by: Muhammad Usama Anjum <[email protected]>
Acked-by: Claudio Imbrenda <[email protected]>
Acked-by: Oliver Upton <[email protected]>
Acked-by: Anup Patel <[email protected]>
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>

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KVM: selftests: Generalize check_clocksource() from kvm_clock_test

Several existing x86 selftests need to check that the underlying system
clocksource is TSC or based on TSC but every test implement

KVM: selftests: Generalize check_clocksource() from kvm_clock_test

Several existing x86 selftests need to check that the underlying system
clocksource is TSC or based on TSC but every test implements its own
check. As a first step towards unification, extract check_clocksource()
from kvm_clock_test and split it into two functions: arch-neutral
'sys_get_cur_clocksource()' and x86-specific 'sys_clocksource_is_tsc()'.
Fix a couple of pre-existing issues in kvm_clock_test: memory leakage in
check_clocksource() and using TEST_ASSERT() instead of TEST_REQUIRE().
The change also makes the test fail when system clocksource can't be read
from sysfs.

Signed-off-by: Vitaly Kuznetsov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[sean: eliminate if-elif pattern just to set a bool true]
Signed-off-by: Sean Christopherson <[email protected]>

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KVM: selftests: Assert that vasprintf() is successful

Assert that vasprintf() succeeds as the "returned" string is undefined
on failure. Checking the result also eliminates the only warning with
de

KVM: selftests: Assert that vasprintf() is successful

Assert that vasprintf() succeeds as the "returned" string is undefined
on failure. Checking the result also eliminates the only warning with
default options in KVM selftests, i.e. is the only thing getting in the
way of compile with -Werror.

lib/test_util.c: In function ‘strdup_printf’:
lib/test_util.c:390:9: error: ignoring return value of ‘vasprintf’
declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
390 | vasprintf(&str, fmt, ap);
| ^~~~~~~~~~~~~~~~~~~~~~~~

Don't bother capturing the return value, allegedly vasprintf() can only
fail due to a memory allocation failure.

Fixes: dfaf20af7649 ("KVM: arm64: selftests: Replace str_with_index with strdup_printf")
Cc: Andrew Jones <[email protected]>
Cc: Haibo Xu <[email protected]>
Cc: Anup Patel <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Tested-by: Andrew Jones <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: arm64: selftests: Replace str_with_index with strdup_printf

The original author of aarch64/get-reg-list.c (me) was wearing
tunnel vision goggles when implementing str_with_index(). There's
no r

KVM: arm64: selftests: Replace str_with_index with strdup_printf

The original author of aarch64/get-reg-list.c (me) was wearing
tunnel vision goggles when implementing str_with_index(). There's
no reason to have such a special case string function. Instead,
take inspiration from glib and implement strdup_printf. The
implementation builds on vasprintf() which requires _GNU_SOURCE,
but we require _GNU_SOURCE in most files already.

Signed-off-by: Andrew Jones <[email protected]>
Signed-off-by: Haibo Xu <[email protected]>
Signed-off-by: Anup Patel <[email protected]>

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selftests: KVM: skip hugetlb tests if huge pages are not available

Right now, if KVM memory stress tests are run with hugetlb sources but hugetlb is
not available (either in the kernel or because /p

selftests: KVM: skip hugetlb tests if huge pages are not available

Right now, if KVM memory stress tests are run with hugetlb sources but hugetlb is
not available (either in the kernel or because /proc/sys/vm/nr_hugepages is 0)
the test will fail with a memory allocation error.

This makes it impossible to add tests that default to hugetlb-backed memory,
because on a machine with a default configuration they will fail. Therefore,
check HugePages_Total as well and, if zero, direct the user to enable hugepages
in procfs. Furthermore, return KSFT_SKIP whenever hugetlb is not available.

Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: implement random number generator for guest code

Implement random number generator for guest code to randomize parts
of the test, making it less predictable and a more accurate refle

KVM: selftests: implement random number generator for guest code

Implement random number generator for guest code to randomize parts
of the test, making it less predictable and a more accurate reflection
of reality.

The random number generator chosen is the Park-Miller Linear
Congruential Generator, a fancy name for a basic and well-understood
random number generator entirely sufficient for this purpose.

Signed-off-by: Colton Lewis <[email protected]>
Reviewed-by: Sean Christopherson <[email protected]>
Reviewed-by: David Matlack <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>

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KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

atoi() doesn't detect errors. There is no way to know that a 0 return
is correct conversion or due to an error.

Introduce atoi_p

KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

atoi() doesn't detect errors. There is no way to know that a 0 return
is correct conversion or due to an error.

Introduce atoi_paranoid() to detect errors and provide correct
conversion. Replace all atoi() calls with atoi_paranoid().

Signed-off-by: Vipin Sharma <[email protected]>
Suggested-by: David Matlack <[email protected]>
Suggested-by: Sean Christopherson <[email protected]>
Reviewed-by: Sean Christopherson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>

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KVM: selftests: Assert mmap HVA is aligned when using HugeTLB

Manually padding and aligning the mmap region is only needed when using
THP. When using HugeTLB, mmap will always return an address alig

KVM: selftests: Assert mmap HVA is aligned when using HugeTLB

Manually padding and aligning the mmap region is only needed when using
THP. When using HugeTLB, mmap will always return an address aligned to
the HugeTLB page size. Add a comment to clarify this and assert the mmap
behavior for HugeTLB.

[Removed requirement that HugeTLB mmaps must be padded per Yanan's
feedback and added assertion that mmap returns aligned addresses
when using HugeTLB.]

Cc: Ben Gardon <[email protected]>
Cc: Yanan Wang <[email protected]>
Cc: Andrew Jones <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Aaron Lewis <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: David Matlack <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Refactor help message for -s backing_src

All selftests that support the backing_src option were printing their
own description of the flag and then calling backing_src_help() to dump

KVM: selftests: Refactor help message for -s backing_src

All selftests that support the backing_src option were printing their
own description of the flag and then calling backing_src_help() to dump
the list of available backing sources. Consolidate the flag printing in
backing_src_help() to align indentation, reduce duplicated strings, and
improve consistency across tests.

Note: Passing "-s" to backing_src_help is unnecessary since every test
uses the same flag. However I decided to keep it for code readability
at the call sites.

While here this opportunistically fixes the incorrectly interleaved
printing -x help message and list of backing source types in
dirty_log_perf_test.

Fixes: 609e6202ea5f ("KVM: selftests: Support multiple slots in dirty_log_perf_test")
Reviewed-by: Ben Gardon <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Signed-off-by: David Matlack <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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selftests: kvm: fix get_run_delay() ignoring fscanf() return warn

Fix get_run_delay() to check fscanf() return value to get rid of the
following warning. When fscanf() fails return MIN_RUN_DELAY_NS

selftests: kvm: fix get_run_delay() ignoring fscanf() return warn

Fix get_run_delay() to check fscanf() return value to get rid of the
following warning. When fscanf() fails return MIN_RUN_DELAY_NS from
get_run_delay(). Move MIN_RUN_DELAY_NS from steal_time.c to test_util.h
so get_run_delay() and steal_time.c can use it.

lib/test_util.c: In function ‘get_run_delay’:
lib/test_util.c:316:2: warning: ignoring return value of ‘fscanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
316 | fscanf(fp, "%ld %ld ", &val[0], &val[1]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan <[email protected]>
Acked-by: Paolo Bonzini <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests: kvm: move get_run_delay() into lib/test_util

get_run_delay() is defined static in xen_shinfo_test and steal_time test.
Move it to lib and remove code duplication.

Signed-off-by: Shuah Kh

selftests: kvm: move get_run_delay() into lib/test_util

get_run_delay() is defined static in xen_shinfo_test and steal_time test.
Move it to lib and remove code duplication.

Signed-off-by: Shuah Khan <[email protected]>
Acked-by: Paolo Bonzini <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests:kvm: fix get_trans_hugepagesz() ignoring fscanf() return warn

Fix get_trans_hugepagesz() to check fscanf() return value to get rid
of the following warning:

lib/test_util.c: In function ‘

selftests:kvm: fix get_trans_hugepagesz() ignoring fscanf() return warn

Fix get_trans_hugepagesz() to check fscanf() return value to get rid
of the following warning:

lib/test_util.c: In function ‘get_trans_hugepagesz’:
lib/test_util.c:138:2: warning: ignoring return value of ‘fscanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
138 | fscanf(f, "%ld", &size);
| ^~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan <[email protected]>
Acked-by: Paolo Bonzini <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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KVM: selftests: Fix compiling errors when initializing the static structure

Errors like below were produced from test_util.c when compiling the KVM
selftests on my local platform.

lib/test_util.c:

KVM: selftests: Fix compiling errors when initializing the static structure

Errors like below were produced from test_util.c when compiling the KVM
selftests on my local platform.

lib/test_util.c: In function 'vm_mem_backing_src_alias':
lib/test_util.c:177:12: error: initializer element is not constant
.flag = anon_flags,
^~~~~~~~~~
lib/test_util.c:177:12: note: (near initialization for 'aliases[0].flag')

The reason is that we are using non-const expressions to initialize the
static structure, which will probably trigger a compiling error/warning
on stricter GCC versions. Fix it by converting the two const variables
"anon_flags" and "anon_huge_flags" into more stable macros.

Fixes: b3784bc28ccc0 ("KVM: selftests: refactor vm_mem_backing_src_type flags")
Reported-by: Zenghui Yu <[email protected]>
Signed-off-by: Yanan Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

show more ...

KVM: selftests: add shared hugetlbfs backing source type

This lets us run the demand paging test on top of a shared
hugetlbfs-backed area. The "shared" is key, as this allows us to
exercise userfaul

KVM: selftests: add shared hugetlbfs backing source type

This lets us run the demand paging test on top of a shared
hugetlbfs-backed area. The "shared" is key, as this allows us to
exercise userfaultfd minor faults on hugetlbfs.

Signed-off-by: Axel Rasmussen <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

show more ...

KVM: selftests: add shmem backing source type

This lets us run the demand paging test on top of a shmem-backed area.
In follow-up commits, we'll 1) leverage this new capability to create an
alias ma

KVM: selftests: add shmem backing source type

This lets us run the demand paging test on top of a shmem-backed area.
In follow-up commits, we'll 1) leverage this new capability to create an
alias mapping, and then 2) use the alias mapping to exercise UFFD minor
faults.

Signed-off-by: Axel Rasmussen <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: refactor vm_mem_backing_src_type flags

Each struct vm_mem_backing_src_alias has a flags field, which denotes
the flags used to mmap() an area of that type. Previously, this field
nev

KVM: selftests: refactor vm_mem_backing_src_type flags

Each struct vm_mem_backing_src_alias has a flags field, which denotes
the flags used to mmap() an area of that type. Previously, this field
never included MAP_PRIVATE | MAP_ANONYMOUS, because
vm_userspace_mem_region_add assumed that *all* types would always use
those flags, and so it hardcoded them.

In a follow-up commit, we'll add a new type: shmem. Areas of this type
must not have MAP_PRIVATE | MAP_ANONYMOUS, and instead they must have
MAP_SHARED.

So, refactor things. Make it so that the flags field of
struct vm_mem_backing_src_alias really is a complete set of flags, and
don't add in any extras in vm_userspace_mem_region_add. This will let us
easily tack on shmem.

Signed-off-by: Axel Rasmussen <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: List all hugetlb src types specified with page sizes

With VM_MEM_SRC_ANONYMOUS_HUGETLB, we currently can only use system
default hugetlb pages to back the testing guest memory. In or

KVM: selftests: List all hugetlb src types specified with page sizes

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 <[email protected]>
Signed-off-by: Yanan Wang <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Add a helper to get system default hugetlb page size

If HUGETLB is configured in the host kernel, then we can know the system
default hugetlb page size through *cat /proc/meminfo*. O

KVM: selftests: Add a helper to get system default hugetlb page size

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]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

show more ...

KVM: selftests: Add a helper to get system configured THP page size

If we want to have some tests about transparent hugepages, the system
configured THP hugepage size should better be known by the t

KVM: selftests: Add a helper to get system configured THP page size

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]>
Reviewed-by: Andrew Jones <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

show more ...

KVM: selftests: Add backing src parameter to dirty_log_perf_test

Add a parameter to control the backing memory type for
dirty_log_perf_test so that the test can be run with hugepages.

To: linux-kse

KVM: selftests: Add backing src parameter to dirty_log_perf_test

Add a parameter to control the backing memory type for
dirty_log_perf_test so that the test can be run with hugepages.

To: [email protected]
CC: Peter Xu <[email protected]>
CC: Andrew Jones <[email protected]>
CC: Thomas Huth <[email protected]>
Signed-off-by: Ben Gardon <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Rename timespec_diff_now to timespec_elapsed

In response to some earlier comments from Peter Xu, rename
timespec_diff_now to the much more sensible timespec_elapsed.

No functional c

KVM: selftests: Rename timespec_diff_now to timespec_elapsed

In response to some earlier comments from Peter Xu, rename
timespec_diff_now to the much more sensible timespec_elapsed.

No functional change intended.

Reviewed-by: Jacob Xu <[email protected]>
Reviewed-by: Makarand Sonare <[email protected]>

Signed-off-by: Ben Gardon <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Introduce the dirty log perf test

The dirty log perf test will time verious dirty logging operations
(enabling dirty logging, dirtying memory, getting the dirty log,
clearing the dir

KVM: selftests: Introduce the dirty log perf test

The dirty log perf test will time verious dirty logging operations
(enabling dirty logging, dirtying memory, getting the dirty log,
clearing the dirty log, and disabling dirty logging) in order to
quantify dirty logging performance. This test can be used to inform
future performance improvements to KVM's dirty logging infrastructure.

This series was tested by running the following invocations on an Intel
Skylake machine:
dirty_log_perf_test -b 20m -i 100 -v 64
dirty_log_perf_test -b 20g -i 5 -v 4
dirty_log_perf_test -b 4g -i 5 -v 32
demand_paging_test -b 20m -v 64
demand_paging_test -b 20g -v 4
demand_paging_test -b 4g -v 32
All behaved as expected.

Signed-off-by: Ben Gardon <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Simplify demand_paging_test with timespec_diff_now

Add a helper function to get the current time and return the time since
a given start time. Use that function to simplify the timek

KVM: selftests: Simplify demand_paging_test with timespec_diff_now

Add a helper function to get the current time and return the time since
a given start time. Use that function to simplify the timekeeping in the
demand paging test.

This series was tested by running the following invocations on an Intel
Skylake machine:
dirty_log_perf_test -b 20m -i 100 -v 64
dirty_log_perf_test -b 20g -i 5 -v 4
dirty_log_perf_test -b 4g -i 5 -v 32
demand_paging_test -b 20m -v 64
demand_paging_test -b 20g -v 4
demand_paging_test -b 4g -v 32
All behaved as expected.

Signed-off-by: Ben Gardon <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Rework timespec functions and usage

The steal_time test's timespec stop condition was wrong and should have
used the timespec functions instead to avoid being wrong, but
timespec_dif

KVM: selftests: Rework timespec functions and usage

The steal_time test's timespec stop condition was wrong and should have
used the timespec functions instead to avoid being wrong, but
timespec_diff had a strange interface. Rework all the timespec API and
its use.

Signed-off-by: Andrew Jones <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

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KVM: selftests: Introduce steal-time test

The steal-time test confirms what is reported to the guest as stolen
time is consistent with the run_delay reported for the VCPU thread
on the host. Both x8

KVM: selftests: Introduce steal-time test

The steal-time test confirms what is reported to the guest as stolen
time is consistent with the run_delay reported for the VCPU thread
on the host. Both x86_64 and AArch64 have the concept of steal/stolen
time so this test is introduced for both architectures.

While adding the test we ensure .gitignore has all tests listed
(it was missing s390x/resets) and that the Makefile has all tests
listed in alphabetical order (not really necessary, but it almost
was already...). We also extend the common API with a new num-guest-
pages call and a new timespec call.

Signed-off-by: Andrew Jones <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

show more ...