Currently in kvm_emulate_hypercall, KVM_HC_MAP_GPA_RANGE is checked
specifically to decide whether a KVM hypercall needs to exit to userspace
or not.  Do the check based on the hypercall_exit_enabled field of
struct kvm_arch.

Also use the API is_kvm_hc_exit_enabled() to replace the opencode.

---
v2:
- Check the return value of __kvm_emulate_hypercall() before checking
  hypercall_exit_enabled to avoid an invalid KVM hypercall nr.
  https://lore.kernel.org/kvm/184d90a8-14a0-494a-9112-365417245911@linux.intel.com/
- Add a warning if a hypercall nr out of the range of hypercall_exit_enabled
  can express.

Binbin Wu (2):
  KVM: x86: Check hypercall's exit to userspace generically
  KVM: x86: Use is_kvm_hc_exit_enabled() instead of opencode

 arch/x86/kvm/svm/sev.c | 4 ++--
 arch/x86/kvm/x86.c     | 6 +++---
 arch/x86/kvm/x86.h     | 7 +++++++
 3 files changed, 12 insertions(+), 5 deletions(-)


base-commit: 332d2c1d713e232e163386c35a3ba0c1b90df83f
-- 
2.43.2