[v3,0/3] kvm: x86: Convey the exit reason, etc. to user-space on emulation failure

Message

David Edmondson July 29, 2021, 1:39 p.m. UTC

To help when debugging failures in the field, if instruction emulation
fails, report the VM exit reason to userspace in order that it can be
recorded.

Sean: hopefully this is something like what you intended. If not,
please clarify and I will have another go. The lack of an ABI for the
debug data does feel messy.

The SGX changes here are compiled but untested.

v3:
- Convey any debug data un-flagged after the ABI specified data in
  struct emulation_failure (Sean)
- Obey the ABI protocol in sgx_handle_emulation_failure() (Sean)

v2:
- Improve patch comments (dmatlock)
- Intel should provide the full exit reason (dmatlock)
- Pass a boolean rather than flags (dmatlock)
- Use the helper in kvm_task_switch() and kvm_handle_memory_failure()
  (dmatlock)
- Describe the exit_reason field of the emulation_failure structure
  (dmatlock)

David Edmondson (3):
  KVM: x86: kvm_x86_ops.get_exit_info should include the exit reason
  KVM: x86: On emulation failure, convey the exit reason, etc. to
    userspace
  KVM: x86: SGX must obey the KVM_INTERNAL_ERROR_EMULATION protocol

 arch/x86/include/asm/kvm_host.h | 12 ++++++--
 arch/x86/kvm/svm/svm.c          |  8 +++--
 arch/x86/kvm/trace.h            | 11 +++----
 arch/x86/kvm/vmx/nested.c       |  2 +-
 arch/x86/kvm/vmx/sgx.c          |  8 ++---
 arch/x86/kvm/vmx/vmx.c          | 11 ++++---
 arch/x86/kvm/x86.c              | 53 ++++++++++++++++++++++++++-------
 include/uapi/linux/kvm.h        |  7 +++++
 8 files changed, 79 insertions(+), 33 deletions(-)