[V2,0/8] Execute hypercalls from guests according to cpu type

This series is posted in context of the discussion at:
https://lore.kernel.org/lkml/Ywa9T+jKUpaHLu%2Fl@google.com/

Changes in v2:
* Addressed comments from Andrew and David
  * Common function with constructor attribute used to setup initial state
  * Changes are split in more logical granules as per feedback

Major changes:
1) Move common startup logic to a single function in kvm_util.c
2) Introduce following APIs:
	kvm_selftest_arch_init: to perform arch specific common startup.
	kvm_arch_post_vm_elf_load: to update the guest memory state to convey
		common information to guests.
3) For x86, capture cpu type at startup and pass on the cpu type to
guest after guest elf is loaded.
4) Execute hypercall instruction from within guest VMs according to the
cpu type. This will help prevent an extra kvm exit during hypercall
execution.

Vishal Annapurve (8):
  KVM: selftests: move common startup logic to kvm_util.c
  KVM: selftests: Add arch specific initialization
  KVM: selftests: Add arch specific post vm load setup
  KVM: selftests: x86: Precompute the result for is_{intel,amd}_cpu()
  KVM: selftests: x86: delete svm_vmcall_test
  KVM: selftests: x86: Execute cpu specific hypercall from nested guests
  Kvm: selftests: x86: Execute cpu specific vmcall instruction
  KVM: selftests: x86: xen: Execute cpu specific vmcall instruction

 tools/testing/selftests/kvm/.gitignore        |  1 -
 .../selftests/kvm/aarch64/arch_timer.c        |  3 -
 .../selftests/kvm/aarch64/hypercalls.c        |  2 -
 .../testing/selftests/kvm/aarch64/vgic_irq.c  |  3 -
 .../selftests/kvm/include/kvm_util_base.h     |  9 +++
 .../selftests/kvm/include/x86_64/processor.h  | 10 +++
 .../selftests/kvm/include/x86_64/vmx.h        |  9 ---
 .../selftests/kvm/lib/aarch64/processor.c     | 22 +++---
 tools/testing/selftests/kvm/lib/elf.c         |  2 +
 tools/testing/selftests/kvm/lib/kvm_util.c    |  8 ++
 .../selftests/kvm/lib/riscv/processor.c       |  8 ++
 .../selftests/kvm/lib/s390x/processor.c       |  8 ++
 .../selftests/kvm/lib/x86_64/perf_test_util.c |  2 +-
 .../selftests/kvm/lib/x86_64/processor.c      | 38 +++++++++-
 .../testing/selftests/kvm/memslot_perf_test.c |  3 -
 tools/testing/selftests/kvm/rseq_test.c       |  3 -
 tools/testing/selftests/kvm/s390x/memop.c     |  2 -
 tools/testing/selftests/kvm/s390x/resets.c    |  2 -
 .../selftests/kvm/s390x/sync_regs_test.c      |  3 -
 .../selftests/kvm/set_memory_region_test.c    |  3 -
 .../kvm/x86_64/cr4_cpuid_sync_test.c          |  3 -
 .../kvm/x86_64/emulator_error_test.c          |  3 -
 .../selftests/kvm/x86_64/hyperv_cpuid.c       |  3 -
 .../selftests/kvm/x86_64/platform_info_test.c |  3 -
 .../kvm/x86_64/pmu_event_filter_test.c        |  3 -
 .../selftests/kvm/x86_64/set_sregs_test.c     |  3 -
 tools/testing/selftests/kvm/x86_64/smm_test.c |  2 +-
 .../testing/selftests/kvm/x86_64/state_test.c |  8 +-
 .../kvm/x86_64/svm_nested_soft_inject_test.c  |  3 -
 .../selftests/kvm/x86_64/svm_vmcall_test.c    | 74 -------------------
 .../selftests/kvm/x86_64/sync_regs_test.c     |  3 -
 .../selftests/kvm/x86_64/userspace_io_test.c  |  3 -
 .../kvm/x86_64/userspace_msr_exit_test.c      |  3 -
 .../kvm/x86_64/vmx_apic_access_test.c         |  2 +-
 .../selftests/kvm/x86_64/vmx_dirty_log_test.c |  2 +-
 .../kvm/x86_64/vmx_nested_tsc_scaling_test.c  |  2 +-
 .../kvm/x86_64/vmx_preemption_timer_test.c    |  2 +-
 .../kvm/x86_64/vmx_tsc_adjust_test.c          |  2 +-
 .../selftests/kvm/x86_64/xen_shinfo_test.c    | 64 ++++++----------
 .../selftests/kvm/x86_64/xen_vmcall_test.c    | 14 +++-
 40 files changed, 138 insertions(+), 205 deletions(-)
 delete mode 100644 tools/testing/selftests/kvm/x86_64/svm_vmcall_test.c

On Thu, Sep 15, 2022 at 12:04:41AM +0000, Vishal Annapurve wrote:
> Consolidate common startup logic in one place by implementing a single
> setup function with __attribute((constructor)) for all selftests within
> kvm_util.c.
> 
> This allows moving logic like:
>         /* Tell stdout not to buffer its content */
>         setbuf(stdout, NULL);
> to a single file for all selftests.
> 
> This will also allow any required setup at entry in future to be done in
> common main function.
> 
> More context is discussed at:
> https://lore.kernel.org/lkml/Ywa9T+jKUpaHLu%2Fl@google.com/
> 
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Vishal Annapurve <vannapurve@google.com>
> ---

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>