[PATCH v8 00/20] KVM: selftests: Add eventfd+VFIO IRQ test

[Sean Christopherson]

David and Josh's series to add a selftest for verifying interrupt delivery
via eventfd (via KVM_IRQFD), and also from a real device, wired up via VFIO.

Gory details in the patches, and in the v5 cover letter.

v8:
 - Explicitly include <time.h>. [Sashiko]
 - Use iova_allocator instea of hardcoding the IOVA. [Sashiko, David]
 - Add a comment explaining why DMA needs to be allocated. [David]
 - Probe /dev/vfio/vfio, not /dev/vfio. [Sashiko, David]

v7:
 - https://lore.kernel.org/all/20260613002031.745413-1-seanjc@xxxxxxxxxx
 - Seed kvm_rng during kvm_selftest_init(). [Sashiko]
 - Seed libc's RNG during kvm_selftest_init(), so that the seed (from random())
   that's printed and passed to kvm_rng isn't the same every time.
 - Init irq_cpu to -1 in all paths. [Sashiko]
 - Require the driver to provide .send_msi(). [David]

v6:
 - Massage most changelogs.
 - Fix SoB ordering issues.
 - Clean up KVM_SET_GSI_ROUTING helper.
 - Remove misleading "IRQ injection" and "emulated eventfd" terminology.
 - Add GUEST_RECEIVED_INTERRUPT() to simplifiy the core loop.
 - Use cpu_relax() in tight loops while waiting for interrupts.
 - Print as much information as possible in the actual assert, instead of
   printing to stdout separately.
 - Make a best guess as to the right VFIO vs. IOMMUFD mode instead of
   assuming IOMMUFD, and give the user the option to overide said guess.
 - Simplify open_proc_irq_smp_affinity_list() +
   write_proc_irq_smp_affinity_list() into proc_irq_set_smp_affinity().
 - Drop print_proc_irq_file() and kvm_print_vcpu_affinity() (for now) to avoid
   potential issues on systems with high CPU counts.
 - Drop the blocking/HLT testing as it was at best broken.
 - Use -e for "empty", not -c for "clear", when completely tearing down GSI
   routing, because routing can be "cleared" without completely emptying the
   routing information.
 - Use the main task's CPU affinity as the available_cpus set.
 - Allow overcommiting vCPUs:pCPUs.
 - Set the target vCPU's affinity instead of batching when vCPU0 is targeted.
 - Add support for 256+ vCPUs with x2APIC.
 - Restrict xAPIC mode to 255 vCPUs.
 - Restrict the test to KVM selftest's max supported vCPUs.

v5:
 - https://lore.kernel.org/all/20260604020143.748245-1-jrhilke@xxxxxxxxxx
 - Rename get_proc_vfio_irq_number() to vfio_msix_to_host_irq()
 - Rename open_proc_irq_affinity() and write_proc_irq_affinity() to include "_smp_affinity_list"
 - Print /proc/irq/<irq>/smp_affinity and effective_affinity on timeout failures
 - Convert IRQ type from 'int' to 'unsigned int' across helpers and the test
 - Fix compiler warnings for uninitialized variables in irq_test.c
 - Remove rate-limiting on affinity changes

v4: https://lore.kernel.org/kvm/20260530002134.558837-1-jrhilke@xxxxxxxxxx

David Matlack (11):
  KVM: selftests: Build and link selftests/vfio/lib into KVM selftests
  KVM: selftests: Add macros to read/write+sync to/from guest memory
  KVM: selftests: Add an irqfd send+receive (and later IRQ bypass) test
  KVM: selftests: Add helper to get host IRQ from device MSI-X for IRQ
    bypass test
  KVM: selftests: Add VFIO device support to eventfd IRQ test
  KVM: selftests: Verify interrupts are received when IRQ affinity
    changes in IRQ test
  KVM: selftests: Add option to set empty routing between IRQs in
    eventfd IRQ test
  KVM: selftests: Make number of IRQs configurable in IRQ test
  KVM: selftests: Verify vCPU migration during IRQ delivery in IRQ test
  KVM: selftests: Make number of vCPUs configurable in IRQ test
  KVM: selftests: Add xAPIC support in eventfd IRQ test

Josh Hilke (6):
  KVM: selftests: Rename guest_rng to kvm_rng
  KVM: selftests: Add helper to generate random u64 in range [min,max]
  KVM: selftests: Add a helper to set proc IRQ affinity for IRQ test
  KVM: selftests: Add kvm_gettid() wrapper and convert users
  KVM: selftests: Add kvm_sched_getaffinity() wrapper and convert users
  KVM: selftests: Add a utility to pin a task to a random CPU, given a
    CPU set

Sean Christopherson (3):
  KVM: selftests: Initialize the default/global pRNG during
    kvm_selftest_init()
  KVM: selftests: Seed libc's RNG before using it to generate a seed for
    KVM's pRNG
  KVM: selftests: Verify non-postable IRQ remapping in IRQ test

 tools/testing/selftests/kvm/Makefile.kvm      |   7 +-
 tools/testing/selftests/kvm/arch_timer.c      |   2 +-
 .../kvm/arm64/arch_timer_edge_cases.c         |   2 +-
 .../selftests/kvm/demand_paging_test.c        |   2 +-
 .../selftests/kvm/dirty_log_perf_test.c       |   4 +-
 tools/testing/selftests/kvm/dirty_log_test.c  |  11 +-
 .../selftests/kvm/include/kvm_syscalls.h      |   7 +
 .../testing/selftests/kvm/include/kvm_util.h  |  12 +
 .../testing/selftests/kvm/include/proc_util.h |  11 +
 .../testing/selftests/kvm/include/test_util.h |  25 +-
 .../selftests/kvm/include/x86/kvm_util_arch.h |   4 +-
 tools/testing/selftests/kvm/irq_test.c        | 362 ++++++++++++++++++
 tools/testing/selftests/kvm/lib/assert.c      |   8 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    |  54 ++-
 tools/testing/selftests/kvm/lib/memstress.c   |   8 +-
 tools/testing/selftests/kvm/lib/proc_util.c   |  54 +++
 tools/testing/selftests/kvm/lib/test_util.c   |  27 +-
 tools/testing/selftests/kvm/mmu_stress_test.c |  15 +-
 tools/testing/selftests/kvm/rseq_test.c       |   6 +-
 tools/testing/selftests/kvm/steal_time.c      |  22 +-
 .../testing/selftests/kvm/x86/sev_dbg_test.c  |   2 +-
 21 files changed, 561 insertions(+), 84 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/proc_util.h
 create mode 100644 tools/testing/selftests/kvm/irq_test.c
 create mode 100644 tools/testing/selftests/kvm/lib/proc_util.c


base-commit: a204badd8432f93b7e862e7dac6db0fe3d65f370
-- 
2.55.0.rc0.799.gd6f94ed593-goog