Commit Graph

11 Commits

Author SHA1 Message Date
David Matlack
286e8903ae KVM: selftests: Use s64 instead of int64_t
Use s64 instead of int64_t to make the KVM selftests code more concise
and more similar to the kernel (since selftests are primarily developed
by kernel developers).

This commit was generated with the following command:

  git ls-files tools/testing/selftests/kvm | xargs sed -i 's/int64_t/s64/g'

Then by manually adjusting whitespace to make checkpatch.pl happy.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://patch.msgid.link/20260420212004.3938325-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-04-20 14:54:16 -07:00
David Matlack
26f8453288 KVM: selftests: Use u64 instead of uint64_t
Use u64 instead of uint64_t to make the KVM selftests code more concise
and more similar to the kernel (since selftests are primarily developed
by kernel developers).

This commit was generated with the following command:

  git ls-files tools/testing/selftests/kvm | xargs sed -i 's/uint64_t/u64/g'

Then by manually adjusting whitespace to make checkpatch.pl happy.

Include <linux/types.h> in include/kvm_util_types.h, iinclude/test_util.h,
and include/x86/pmu.h to pick up the tools-defined u64.  Arguably, all
headers (especially kvm_util_types.h) should have already been including
stdint.h to get uint64_t from the libc headers, but the missing dependency
only rears its head once KVM uses u64 instead of uint64_t.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
[sean: rename pread_uint64() => pread_u64, expand on types.h include]
Link: https://patch.msgid.link/20260420212004.3938325-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-04-20 14:54:16 -07:00
Colin Ian King
75418e222e KVM: selftests: Fix spelling mistake "UFFDIO_CONINUE" -> "UFFDIO_CONTINUE"
There is a spelling mistake in a PER_PAGE_DEBUG debug message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20250227220819.656780-1-colin.i.king@gmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-02-28 09:12:52 -08:00
Paolo Bonzini
dee7ea42a1 KVM selftests treewide updates for 6.10:
- Define _GNU_SOURCE for all selftests to fix a warning that was introduced by
    a change to kselftest_harness.h late in the 6.9 cycle, and because forcing
    every test to #define _GNU_SOURCE is painful.
 
  - Provide a global psuedo-RNG instance for all tests, so that library code can
    generate random, but determinstic numbers.
 
  - Use the global pRNG to randomly force emulation of select writes from guest
    code on x86, e.g. to help validate KVM's emulation of locked accesses.
 
  - Rename kvm_util_base.h back to kvm_util.h, as the weird layer of indirection
    was added purely to avoid manually #including ucall_common.h in a handful of
    locations.
 
  - Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception
    handlers at VM creation, instead of forcing tests to manually trigger the
    related setup.
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Merge tag 'kvm-x86-selftests_utils-6.10' of https://github.com/kvm-x86/linux into HEAD

KVM selftests treewide updates for 6.10:

 - Define _GNU_SOURCE for all selftests to fix a warning that was introduced by
   a change to kselftest_harness.h late in the 6.9 cycle, and because forcing
   every test to #define _GNU_SOURCE is painful.

 - Provide a global psuedo-RNG instance for all tests, so that library code can
   generate random, but determinstic numbers.

 - Use the global pRNG to randomly force emulation of select writes from guest
   code on x86, e.g. to help validate KVM's emulation of locked accesses.

 - Rename kvm_util_base.h back to kvm_util.h, as the weird layer of indirection
   was added purely to avoid manually #including ucall_common.h in a handful of
   locations.

 - Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception
   handlers at VM creation, instead of forcing tests to manually trigger the
   related setup.
2024-05-12 03:18:11 -04:00
Sean Christopherson
730cfa45b5 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 <usama.anjum@collabora.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20240423190308.2883084-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-04-29 12:49:10 -07:00
Anish Moorthy
0cba6442e9 KVM: selftests: Use EPOLL in userfaultfd_util reader threads
With multiple reader threads POLLing a single UFFD, the demand paging test
suffers from the thundering herd problem: performance degrades as the
number of reader threads is increased. Solve this issue [1] by switching
the the polling mechanism to EPOLL + EPOLLEXCLUSIVE.

Also, change the error-handling convention of uffd_handler_thread_fn.
Instead of just printing errors and returning early from the polling
loop, check for them via TEST_ASSERT(). "return NULL" is reserved for a
successful exit from uffd_handler_thread_fn, i.e. one triggered by a
write to the exit pipe.

Performance samples generated by the command in [2] are given below.

Num Reader Threads, Paging Rate (POLL), Paging Rate (EPOLL)
1      249k      185k
2      201k      235k
4      186k      155k
16     150k      217k
32     89k       198k

[1] Single-vCPU performance does suffer somewhat.
[2] ./demand_paging_test -u MINOR -s shmem -v 4 -o -r <num readers>

Signed-off-by: Anish Moorthy <amoorthy@google.com>
Acked-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20240215235405.368539-13-amoorthy@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-04-09 14:30:14 -07:00
Anish Moorthy
df4ec5aada KVM: selftests: Allow many vCPUs and reader threads per UFFD in demand paging test
At the moment, demand_paging_test does not support profiling/testing
multiple vCPU threads concurrently faulting on a single uffd because

    (a) "-u" (run test in userfaultfd mode) creates a uffd for each vCPU's
        region, so that each uffd services a single vCPU thread.
    (b) "-u -o" (userfaultfd mode + overlapped vCPU memory accesses)
        simply doesn't work: the test tries to register the same memory
        to multiple uffds, causing an error.

Add support for many vcpus per uffd by
    (1) Keeping "-u" behavior unchanged.
    (2) Making "-u -a" create a single uffd for all of guest memory.
    (3) Making "-u -o" implicitly pass "-a", solving the problem in (b).
In cases (2) and (3) all vCPU threads fault on a single uffd.

With potentially multiple vCPUs per UFFD, it makes sense to allow
configuring the number of reader threads per UFFD as well: add the "-r"
flag to do so.

Signed-off-by: Anish Moorthy <amoorthy@google.com>
Acked-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20240215235405.368539-12-amoorthy@google.com
[sean: fix kernel style violations, use calloc() for arrays]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-04-09 14:28:53 -07:00
Andrew Jones
250e138d87 KVM: selftests: Remove redundant newlines
TEST_* functions append their own newline. Remove newlines from
TEST_* callsites to avoid extra newlines in output.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231206170241.82801-8-ajones@ventanamicro.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-01-29 08:39:14 -08:00
Peter Xu
21912a653d KVM: selftests: Allow dumping per-vcpu info for uffd threads
There's one PER_VCPU_DEBUG in per-vcpu uffd threads but it's never hit.

Trigger that when quit in normal ways (kick pollfd[1]), meanwhile fix the
number of nanosec calculation.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20230427201112.2164776-3-peterx@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-05-31 14:05:15 -07:00
Paolo Bonzini
eb5618911a KVM/arm64 updates for 6.2
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
   option to keep the good old dirty log around for pages that are
   dirtied by something other than a vcpu.
 
 - Switch to the relaxed parallel fault handling, using RCU to delay
   page table reclaim and giving better performance under load.
 
 - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
   option, which multi-process VMMs such as crosvm rely on.
 
 - Merge the pKVM shadow vcpu state tracking that allows the hypervisor
   to have its own view of a vcpu, keeping that state private.
 
 - Add support for the PMUv3p5 architecture revision, bringing support
   for 64bit counters on systems that support it, and fix the
   no-quite-compliant CHAIN-ed counter support for the machines that
   actually exist out there.
 
 - Fix a handful of minor issues around 52bit VA/PA support (64kB pages
   only) as a prefix of the oncoming support for 4kB and 16kB pages.
 
 - Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
   stage-2 faults and access tracking. You name it, we got it, we
   probably broke it.
 
 - Pick a small set of documentation and spelling fixes, because no
   good merge window would be complete without those.
 
 As a side effect, this tag also drags:
 
 - The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
   series
 
 - A shared branch with the arm64 tree that repaints all the system
   registers to match the ARM ARM's naming, and resulting in
   interesting conflicts
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Merge tag 'kvmarm-6.2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.2

- Enable the per-vcpu dirty-ring tracking mechanism, together with an
  option to keep the good old dirty log around for pages that are
  dirtied by something other than a vcpu.

- Switch to the relaxed parallel fault handling, using RCU to delay
  page table reclaim and giving better performance under load.

- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
  option, which multi-process VMMs such as crosvm rely on.

- Merge the pKVM shadow vcpu state tracking that allows the hypervisor
  to have its own view of a vcpu, keeping that state private.

- Add support for the PMUv3p5 architecture revision, bringing support
  for 64bit counters on systems that support it, and fix the
  no-quite-compliant CHAIN-ed counter support for the machines that
  actually exist out there.

- Fix a handful of minor issues around 52bit VA/PA support (64kB pages
  only) as a prefix of the oncoming support for 4kB and 16kB pages.

- Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
  stage-2 faults and access tracking. You name it, we got it, we
  probably broke it.

- Pick a small set of documentation and spelling fixes, because no
  good merge window would be complete without those.

As a side effect, this tag also drags:

- The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
  series

- A shared branch with the arm64 tree that repaints all the system
  registers to match the ARM ARM's naming, and resulting in
  interesting conflicts
2022-12-09 09:12:12 +01:00
Ricardo Koller
a93871d0ea KVM: selftests: Add a userfaultfd library
Move the generic userfaultfd code out of demand_paging_test.c into a
common library, userfaultfd_util. This library consists of a setup and a
stop function. The setup function starts a thread for handling page
faults using the handler callback function. This setup returns a
uffd_desc object which is then used in the stop function (to wait and
destroy the threads).

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-2-ricarkol@google.com
2022-11-10 19:10:27 +00:00