KVM: x86: Don't re-execute instruction when not passing CR2 value

KVM: x86: Don't re-execute instruction when not passing CR2 value

In case of instruction-decode failure or emulation failure,
x86_emulate_instruction() will call reexecute_instruction() which will
attempt to use the cr2 value passed to x86_emulate_instruction().
However, when x86_emulate_instruction() is called from
emulate_instruction(), cr2 is not passed (passed as 0) and therefore
it doesn't make sense to execute reexecute_instruction() logic at all.

Fixes: 51d8b66199e9 ("KVM: cleanup emulate_instruction")
Signed-off-by: Liran Alon <[email protected]>
Reviewed-by: Nikita Leshenko <[email protected]>
Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
Reviewed-by: Wanpeng Li <[email protected]>
Signed-off-by: Radim Krčmář <[email protected]>