linux.git/tools/testing/selftests/kvm, branch master Linux kernel source tree Merge tag 'kvm-x86-fixes-7.1-rc6' of https://github.com/kvm-x86/linux into HEAD 2026-05-29T17:28:16+00:00 Paolo Bonzini pbonzini@redhat.com 2026-05-29T17:28:16+00:00 b3978970165729eea7a80d10d52f17cc495672cd KVM x86 fixes for 7.1-rcN - Include the kernel's linux/mman.h in KVM selftests to ensure MADV_COLLAPSE is defined, as older libc versions may not provide it. - Include execinfo.h if and only if KVM selftests are building against glibc, and provide a test_dump_stack() for non-glibc builds. - Fudge around an RCU splat in the emegerncy reboot code that is technically a legitimate flaw, but in practice is a non-issue and fixing the flaw, e.g. by adding locking, would incur meaningful risk, i.e. do more harm than good. - Rate-limit global clock updates once again (but without delayed work), as KVM was subtly relying on the old rate-limiting for NPT correction to guard against "update storms" when running without a master clock on systems with overcommitted CPUs. - Fix a brown paper bag goof where KVM checked if ERAPS is "dirty" instead of marking it dirty when emulating INVPCID. - Flush the TLB when transitioning from xAVIC => x2AVIC to ensure the CPU TLB doesn't contain AVIC-tagged entries for the APIC base GPA. 
KVM x86 fixes for 7.1-rcN

 - Include the kernel's linux/mman.h in KVM selftests to ensure MADV_COLLAPSE
   is defined, as older libc versions may not provide it.

 - Include execinfo.h if and only if KVM selftests are building against glibc,
   and provide a test_dump_stack() for non-glibc builds.

 - Fudge around an RCU splat in the emegerncy reboot code that is technically
   a legitimate flaw, but in practice is a non-issue and fixing the flaw, e.g.
   by adding locking, would incur meaningful risk, i.e. do more harm than good.

 - Rate-limit global clock updates once again (but without delayed work), as
   KVM was subtly relying on the old rate-limiting for NPT correction to guard
   against "update storms" when running without a master clock on systems with
   overcommitted CPUs.

 - Fix a brown paper bag goof where KVM checked if ERAPS is "dirty" instead of
   marking it dirty when emulating INVPCID.

 - Flush the TLB when transitioning from xAVIC => x2AVIC to ensure the CPU TLB
   doesn't contain AVIC-tagged entries for the APIC base GPA.
KVM: selftests: Verify that KVM returns the configured APIC cycle length 2026-05-23T08:07:40+00:00 Sean Christopherson seanjc@google.com 2026-05-22T17:35:26+00:00 d9c41dc531b0e8feb046ee3d31ce37657101b137 Add checks in the APIC bus clock test to verify that querying KVM_CAP_X86_APIC_BUS_CYCLES_NS on the VM after changing the frequency returns the VM's actual APIC cycle length, not KVM's default. For giggles, verify that KVM still returns its default frequency for the system-scoped check. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20260522173526.3539407-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 
Add checks in the APIC bus clock test to verify that querying
KVM_CAP_X86_APIC_BUS_CYCLES_NS on the VM after changing the frequency
returns the VM's actual APIC cycle length, not KVM's default.  For
giggles, verify that KVM still returns its default frequency for the
system-scoped check.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260522173526.3539407-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: elf: Include <endian.h> instead of <bits/endian.h> 2026-05-23T08:05:26+00:00 Hisam Mehboob hisamshar@gmail.com 2026-04-09T16:40:22+00:00 2d42c7cf1a2dad694db0c518b0e004502859f11c <bits/endian.h> is a glibc-internal header that explicitly states it should never be included directly: #error "Never use <bits/endian.h> directly; include <endian.h> instead." Replace it with the correct public header <endian.h> which works on all C libraries including musl. Building KVM selftests with musl-gcc fails with: lib/elf.c:10:10: fatal error: bits/endian.h: No such file or directory Fixes: 6089ae0bd5e1 ("kvm: selftests: add sync_regs_test") Signed-off-by: Hisam Mehboob <hisamshar@gmail.com> Message-ID: <20260409164020.1575176-4-hisamshar@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 
<bits/endian.h> is a glibc-internal header that explicitly states it
should never be included directly:

  #error "Never use <bits/endian.h> directly; include <endian.h> instead."

Replace it with the correct public header <endian.h> which works on
all C libraries including musl. Building KVM selftests with musl-gcc
fails with:

  lib/elf.c:10:10: fatal error: bits/endian.h: No such file or directory

Fixes: 6089ae0bd5e1 ("kvm: selftests: add sync_regs_test")
Signed-off-by: Hisam Mehboob <hisamshar@gmail.com>
Message-ID: <20260409164020.1575176-4-hisamshar@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Guard execinfo.h inclusion for non-glibc builds 2026-05-13T17:38:02+00:00 Hisam Mehboob hisamshar@gmail.com 2026-04-09T15:38:47+00:00 34065a5f3cf94886e59e2a8b5db00515f32d6cf2 The backtrace() function and execinfo.h are GNU extensions available in glibc but not in non-glibc C libraries such as musl. Building KVM selftests with musl-gcc fails with: lib/assert.c:9:10: fatal error: execinfo.h: No such file or directory Fix this by guarding the inclusion of execinfo.h and the stack dumping logic under #ifdef __GLIBC__. For non-glibc builds, provide a local stub for test_dump_stack(). Suggested-by: Aqib Faruqui <aqibaf@amazon.com> Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Hisam Mehboob <hisamshar@gmail.com> Link: https://patch.msgid.link/20260409153846.1502656-2-hisamshar@gmail.com Signed-off-by: Sean Christopherson <seanjc@google.com> 
The backtrace() function and execinfo.h are GNU extensions available
in glibc but not in non-glibc C libraries such as musl. Building KVM
selftests with musl-gcc fails with:

  lib/assert.c:9:10: fatal error: execinfo.h: No such file or directory

Fix this by guarding the inclusion of execinfo.h and the stack dumping
logic under #ifdef __GLIBC__. For non-glibc builds, provide a local
stub for test_dump_stack().

Suggested-by: Aqib Faruqui <aqibaf@amazon.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Hisam Mehboob <hisamshar@gmail.com>
Link: https://patch.msgid.link/20260409153846.1502656-2-hisamshar@gmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
KVM: selftests: Include sys/mman.h *and* linux/mman.h, via kvm_syscalls.h 2026-05-13T16:53:43+00:00 Sean Christopherson seanjc@google.com 2026-04-28T01:25:03+00:00 6d3790bc689de9f18fae01c21f02e7d6d425534c Include both linux/mman.h (the kernel provided version) and sys/mman.h (the libc provided version) throughout KVM selftests, by way of kvm_syscalls.h (which should have been including sys/mman.h anyways). Pulling in the kernel's version fixes compilation errors with the guest_memfd test on older versions of libc due to a recent commit adding MADV_COLLAPSE testing. In file included from include/kvm_util.h:8, from guest_memfd_test.c:21: guest_memfd_test.c: In function ‘test_collapse’: guest_memfd_test.c:219:47: error: ‘MADV_COLLAPSE’ undeclared (first use in this function); did you mean ‘MADV_COLD’? 219 | TEST_ASSERT_EQ(madvise(mem, pmd_size, MADV_COLLAPSE), -1); | ^~~~~~~~~~~~~ include/test_util.h:62:16: note: in definition of macro ‘TEST_ASSERT_EQ’ 62 | typeof(a) __a = (a); \ | ^ guest_memfd_test.c:219:47: note: each undeclared identifier is reported only once for each function it appears in 219 | TEST_ASSERT_EQ(madvise(mem, pmd_size, MADV_COLLAPSE), -1); | ^~~~~~~~~~~~~ include/test_util.h:62:16: note: in definition of macro ‘TEST_ASSERT_EQ’ 62 | typeof(a) __a = (a); \ | ^ Route the includes through kvm_syscalls.h to try and avoid a future game of whack-a-mole, i.e. so that future expansion of test coverage doesn't run into the same problem. To discourage use of sys/mman.h, opportunistically include the kernel's version of mman.h in test_util.h as it only needs MAP_SHARED, i.e. only needs the full set of kernel defs, not the libc syscall wrappers. Fixes: 9830209b4ae8 ("KVM: selftests: Test MADV_COLLAPSE on guest_memfd") Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Closes: https://lore.kernel.org/all/20260427204313.50741-1-rick.p.edgecombe@intel.com Link: https://patch.msgid.link/20260428012503.1213654-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> 
Include both linux/mman.h (the kernel provided version) and sys/mman.h (the
libc provided version) throughout KVM selftests, by way of kvm_syscalls.h
(which should have been including sys/mman.h anyways).  Pulling in the
kernel's version fixes compilation errors with the guest_memfd test on
older versions of libc due to a recent commit adding MADV_COLLAPSE testing.

  In file included from include/kvm_util.h:8,
                   from guest_memfd_test.c:21:
  guest_memfd_test.c: In function ‘test_collapse’:
  guest_memfd_test.c:219:47: error: ‘MADV_COLLAPSE’ undeclared (first use in this function); did you mean ‘MADV_COLD’?
      219 |         TEST_ASSERT_EQ(madvise(mem, pmd_size, MADV_COLLAPSE), -1);
          |                                               ^~~~~~~~~~~~~
    include/test_util.h:62:16: note: in definition of macro ‘TEST_ASSERT_EQ’
       62 |         typeof(a) __a = (a);                                            \
          |                ^
    guest_memfd_test.c:219:47: note: each undeclared identifier is reported only once for each function it appears in
      219 |         TEST_ASSERT_EQ(madvise(mem, pmd_size, MADV_COLLAPSE), -1);
          |                                               ^~~~~~~~~~~~~
    include/test_util.h:62:16: note: in definition of macro ‘TEST_ASSERT_EQ’
       62 |         typeof(a) __a = (a);                                            \
          |                ^

Route the includes through kvm_syscalls.h to try and avoid a future game
of whack-a-mole, i.e. so that future expansion of test coverage doesn't run
into the same problem.

To discourage use of sys/mman.h, opportunistically include the kernel's
version of mman.h in test_util.h as it only needs MAP_SHARED, i.e. only
needs the full set of kernel defs, not the libc syscall wrappers.

Fixes: 9830209b4ae8 ("KVM: selftests: Test MADV_COLLAPSE on guest_memfd")
Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Closes: https://lore.kernel.org/all/20260427204313.50741-1-rick.p.edgecombe@intel.com
Link: https://patch.msgid.link/20260428012503.1213654-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
KVM: selftests: Ensure gmem file sizes are multiple of host page size 2026-05-12T20:26:10+00:00 Sean Christopherson seanjc@google.com 2026-05-12T15:56:34+00:00 87c810160ed738cd983e4a65ebe9709927c702c9 When creating a guest_memfd file and associated memslot to validate shared guest memory, size the file+memslot to the maximum of the host or guest page size. Attempting to allocate a single guest page will fail if the host page size is greater than the guest page size, as KVM requires that the size of memslots and guest_memfd files are a multiple of the host page size. For simplicity, verify the entire file can be shared between guest and host, e.g. instead of trying to validate "partial" mappings. Fixes: 42188667be38 ("KVM: selftests: Add guest_memfd testcase to fault-in on !mmap()'d memory") Reported-by: Zenghui Yu <zenghui.yu@linux.dev> Closes: https://lore.kernel.org/all/0064952b-048c-455d-ad89-e27e5cb82591@linux.dev Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20260512155634.772602-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 
When creating a guest_memfd file and associated memslot to validate shared
guest memory, size the file+memslot to the maximum of the host or guest
page size.  Attempting to allocate a single guest page will fail if the
host page size is greater than the guest page size, as KVM requires that
the size of memslots and guest_memfd files are a multiple of the host page
size.

For simplicity, verify the entire file can be shared between guest and host,
e.g. instead of trying to validate "partial" mappings.

Fixes: 42188667be38 ("KVM: selftests: Add guest_memfd testcase to fault-in on !mmap()'d memory")
Reported-by: Zenghui Yu <zenghui.yu@linux.dev>
Closes: https://lore.kernel.org/all/0064952b-048c-455d-ad89-e27e5cb82591@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260512155634.772602-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: arm64: Fix steal_time test after UAPI refactoring 2026-05-06T16:09:03+00:00 Sebastian Ott sebott@redhat.com 2026-05-04T11:28:08+00:00 fc240715fc5003538ff530e3cfb985e7769b7171 Fix the following failure to the steal_time test on arm64 by making the timer address known to the guest. ==== Test Assertion Failure ==== steal_time.c:229: !ret pid=18514 tid=18514 errno=22 - Invalid argument 1 0x000000000040252f: check_steal_time_uapi at steal_time.c:229 (discriminator 20) 2 (inlined by) main at steal_time.c:537 (discriminator 20) 3 0x0000ffffa23d621b: ?? ??:0 4 0x0000ffffa23d62fb: ?? ??:0 5 0x0000000000402b6f: _start at ??:? KVM_SET_DEVICE_ATTR failed, rc: -1 errno: 22 (Invalid argument) Fixes: 40351ed924dd ("KVM: selftests: Refactor UAPI tests into dedicated function") Signed-off-by: Sebastian Ott <sebott@redhat.com> Link: https://patch.msgid.link/20260504112808.21276-1-sebott@redhat.com Signed-off-by: Marc Zyngier <maz@kernel.org> 
Fix the following failure to the steal_time test on arm64 by making
the timer address known to the guest.

==== Test Assertion Failure ====
  steal_time.c:229: !ret
  pid=18514 tid=18514 errno=22 - Invalid argument
     1  0x000000000040252f: check_steal_time_uapi at steal_time.c:229 (discriminator 20)
     2   (inlined by) main at steal_time.c:537 (discriminator 20)
     3  0x0000ffffa23d621b: ?? ??:0
     4  0x0000ffffa23d62fb: ?? ??:0
     5  0x0000000000402b6f: _start at ??:?
  KVM_SET_DEVICE_ATTR failed, rc: -1 errno: 22 (Invalid argument)

Fixes: 40351ed924dd ("KVM: selftests: Refactor UAPI tests into dedicated function")
Signed-off-by: Sebastian Ott <sebott@redhat.com>
Link: https://patch.msgid.link/20260504112808.21276-1-sebott@redhat.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Merge tag 'kvm-x86-selftests_kernel_types-7.1' of https://github.com/kvm-x86/linux into HEAD 2026-04-27T08:24:41+00:00 Paolo Bonzini pbonzini@redhat.com 2026-04-27T08:24:41+00:00 39f1c201b93f4ff71631bac72cff6eb155f976a4 KVM selftests type renames for 7.1 Renames types across all KVM selftests to more closely align with types used in the kernel: vm_vaddr_t -> gva_t vm_paddr_t -> gpa_t uint64_t -> u64 uint32_t -> u32 uint16_t -> u16 uint8_t -> u8 int64_t -> s64 int32_t -> s32 int16_t -> s16 int8_t -> s8 Using the kernel's preferred types eliminates a source of friction for many contributors, as the majority of KVM selftests contributions come from kernel developers. The kernel names are also shorter, which allows for more concise code, and in any many cases eliminates newlines thanks to shorter types and parameter names. Rename variables and parameters as well as types, e.g. gpa instead of paddr, to again align with the kernel, and in a few cases to remove ambiguity, e.g. where paddr is used to refer to a _host_ physical address. 
KVM selftests type renames for 7.1

Renames types across all KVM selftests to more closely align with types used
in the kernel:

  vm_vaddr_t -> gva_t
  vm_paddr_t -> gpa_t

  uint64_t -> u64
  uint32_t -> u32
  uint16_t -> u16
  uint8_t  -> u8

  int64_t -> s64
  int32_t -> s32
  int16_t -> s16
  int8_t  -> s8

Using the kernel's preferred types eliminates a source of friction for many
contributors, as the majority of KVM selftests contributions come from kernel
developers.  The kernel names are also shorter, which allows for more concise
code, and in any many cases eliminates newlines thanks to shorter types and
parameter names.

Rename variables and parameters as well as types, e.g. gpa instead of paddr,
to again align with the kernel, and in a few cases to remove ambiguity, e.g.
where paddr is used to refer to a _host_ physical address.
KVM: selftests: Add check_steal_time_uapi() implementation for LoongArch 2026-04-27T08:23:17+00:00 Sean Christopherson seanjc@google.com 2026-04-20T19:26:44+00:00 1101baca98669833fb3ad2dcd24bc06f9e70e66b Define check_steal_time_uapi() for LoongArch so that the steal_time test builds. Note, while LoongArch's steal_time_init() has some funky asserts, none of the code is uniquely verifying KVM's uAPI. Cc: Jiakai Xu <xujiakai2025@iscas.ac.cn> Cc: Jiakai Xu <jiakaiPeanut@gmail.com> Cc: Andrew Jones <andrew.jones@oss.qualcomm.com> Cc: Anup Patel <anup@brainfault.org> Cc: Tianrui Zhao <zhaotianrui@loongson.cn> Cc: Bibo Mao <maobibo@loongson.cn> Cc: Huacai Chen <chenhuacai@kernel.org> Fixes: 40351ed924dd ("KVM: selftests: Refactor UAPI tests into dedicated function") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20260420192644.3892050-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 
Define check_steal_time_uapi() for LoongArch so that the steal_time test
builds.  Note, while LoongArch's steal_time_init() has some funky asserts,
none of the code is uniquely verifying KVM's uAPI.

Cc: Jiakai Xu <xujiakai2025@iscas.ac.cn>
Cc: Jiakai Xu <jiakaiPeanut@gmail.com>
Cc: Andrew Jones <andrew.jones@oss.qualcomm.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Huacai Chen <chenhuacai@kernel.org>
Fixes: 40351ed924dd ("KVM: selftests: Refactor UAPI tests into dedicated function")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260420192644.3892050-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Replace "paddr" with "gpa" throughout 2026-04-20T21:54:17+00:00 Sean Christopherson seanjc@google.com 2026-04-20T21:20:04+00:00 dfd2a8b07c6cc94145e11d87d2f11137d6444854 Replace all variations of "paddr" variables in KVM selftests with "gpa", with the exception of the ELF structures, as those fields are not specific to guest virtual addresses, to complete the conversion from vm_paddr_t to gpa_t. No functional change intended. Link: https://patch.msgid.link/20260420212004.3938325-20-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> 
Replace all variations of "paddr" variables in KVM selftests with "gpa",
with the exception of the ELF structures, as those fields are not specific
to guest virtual addresses, to complete the conversion from vm_paddr_t to
gpa_t.

No functional change intended.

Link: https://patch.msgid.link/20260420212004.3938325-20-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>