Re: [PATCH v2 2/2] x86/hvm: Don't intercept #UD exceptions in general

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 27/01/2016 19:52, Konrad Rzeszutek Wilk wrote:
>> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
>> index 674feea..7a15d49 100644
>> --- a/xen/arch/x86/hvm/hvm.c
>> +++ b/xen/arch/x86/hvm/hvm.c
>> @@ -93,12 +93,10 @@ unsigned long __section(".bss.page_aligned")
>>  static bool_t __initdata opt_hap_enabled = 1;
>>  boolean_param("hap", opt_hap_enabled);
>>  
>> -#ifndef NDEBUG
>> +#ifndef opt_hvm_fep
>>  /* Permit use of the Forced Emulation Prefix in HVM guests */
>> -static bool_t opt_hvm_fep;
>> +bool_t opt_hvm_fep;
>>  boolean_param("hvm_fep", opt_hvm_fep);
> Since you remove the debug option you should probably also update the 
> documentation which says: ">Recognized in debug builds of the hypervisor only."

This doesn't change the "debug-only"-ness of the option.

Observe in the first hunk to hvm.h that opt_hvm_fep is defined to 0 in a
non-debug build, which causes this hunk to be omitted.

This actually matches the original introduction of opt_hvm_fep, before
it was reduced in scope to only hvm.c.  I now need it available again in
other translation units.

~Andrew