Re: [PATCH RFC V6 3/5] xen, libxc: Force-enable relevant MSR events

[Razvan Cojocaru <rcojocaru@bitdefender.com>]

On 08/12/2014 06:06 PM, Jan Beulich wrote:
>>>> On 11.08.14 at 17:08, <rcojocaru@bitdefender.com> wrote:
>> --- a/xen/arch/x86/hvm/vmx/vmcs.c
>> +++ b/xen/arch/x86/hvm/vmx/vmcs.c
>> @@ -39,6 +39,7 @@
>>  #include <xen/keyhandler.h>
>>  #include <asm/shadow.h>
>>  #include <asm/tboot.h>
>> +#include <asm/mem_event.h>
>>  
>>  static bool_t __read_mostly opt_vpid_enabled = 1;
>>  boolean_param("vpid", opt_vpid_enabled);
>> @@ -695,11 +696,31 @@ static void vmx_set_host_env(struct vcpu *v)
>>  void vmx_disable_intercept_for_msr(struct vcpu *v, u32 msr, int type)
>>  {
>>      unsigned long *msr_bitmap = v->arch.hvm_vmx.msr_bitmap;
>> +    struct domain *d = v->domain;
>>  
>>      /* VMX MSR bitmap supported? */
>>      if ( msr_bitmap == NULL )
>>          return;
>>  
>> +    if ( mem_event_check_ring(&d->mem_event->access) &&
>> +         d->arch.hvm_domain.introspection_enabled )
>> +    {
>> +        /* Filter out MSR-s needed for memory introspection */
>> +        switch ( msr )
>> +        {
>> +        case MSR_IA32_SYSENTER_EIP:
>> +        case MSR_IA32_SYSENTER_ESP:
>> +        case MSR_IA32_SYSENTER_CS:
>> +        case MSR_IA32_MC0_CTL:
>> +        case MSR_STAR:
>> +        case MSR_LSTAR:
>> +            return;
> 
> So you're adding an array further down, but just to use it there? My
> main point in asking for something like that was to have a _single_
> place where all the relevant MSRs get enumerated.

You're right, I'll change the code (and modify it to address the rest of
your comments as well).


Thanks,
Razvan Cojocaru