KVM: x86: Remove emulation_result enums, EMULATE_{DONE,FAIL,USER_EXIT}

Deferring emulation failure handling (in some cases) to the caller of
x86_emulate_instruction() has proven fragile, e.g. multiple instances of
KVM not setting run->exit_reason on EMULATE_FAIL, largely due to it
being difficult to discern what emulation types can return what result,
and which combination of types and results are handled where.

Now that x86_emulate_instruction() always handles emulation failure,
i.e. EMULATION_FAIL is only referenced in callers, remove the
emulation_result enums entirely.  Per KVM's existing exit handling
conventions, return '0' and '1' for "exit to userspace" and "resume
guest" respectively.  Doing so cleans up many callers, e.g. they can
return kvm_emulate_instruction() directly instead of having to interpret
its result.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson
2019-08-27 14:40:38 -07:00
committed by Paolo Bonzini
parent 8fff2710ea
commit 60fc3d02d5
5 changed files with 49 additions and 78 deletions

View File

@@ -1315,12 +1315,6 @@ extern u64 kvm_default_tsc_scaling_ratio;
extern u64 kvm_mce_cap_supported;
enum emulation_result {
EMULATE_DONE, /* no further processing */
EMULATE_USER_EXIT, /* kvm_run ready for userspace exit */
EMULATE_FAIL, /* can't emulate this instruction */
};
#define EMULTYPE_NO_DECODE (1 << 0)
#define EMULTYPE_TRAP_UD (1 << 1)
#define EMULTYPE_SKIP (1 << 2)