Re: [PATCH 1/2] Add code to track call origin for msr assignment.

[Marcelo Tosatti <mtosatti@redhat.com>]

On Thu, Nov 15, 2012 at 12:25:45PM -0800, Will Auld wrote:
> In order to track who initiated the call (host or guest) to modify an msr
> value I have changed function call parameters along the call path. The
> specific change is to add a struct pointer parameter that points to (index,
> data, caller) information rather than having this information passed as
> individual parameters.
> 
> The initial use for this capability is for updating the IA32_TSC_ADJUST
> msr while setting the tsc value. It is anticipated that this capability
> is useful other tasks.
> 
> Signed-off-by: Will Auld <will.auld@intel.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 12 +++++++++---
>  arch/x86/kvm/svm.c              | 21 +++++++++++++++------
>  arch/x86/kvm/vmx.c              | 24 +++++++++++++++++-------
>  arch/x86/kvm/x86.c              | 23 +++++++++++++++++------
>  arch/x86/kvm/x86.h              |  2 +-
>  5 files changed, 59 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 42bce48..a3aac1c 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -883,9 +883,9 @@ EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);
>   * Returns 0 on success, non-0 otherwise.
>   * Assumes vcpu_load() was already called.
>   */
> -int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
> +int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
>  {
> -	return kvm_x86_ops->set_msr(vcpu, msr_index, data);
> +	return kvm_x86_ops->set_msr(vcpu, msr);
>  }
>  
>  /*

> @@ -4286,7 +4293,11 @@ static int emulator_get_msr(struct x86_emulate_ctxt *ctxt,
>  static int emulator_set_msr(struct x86_emulate_ctxt *ctxt,
>  			    u32 msr_index, u64 data)
>  {
> -	return kvm_set_msr(emul_to_vcpu(ctxt), msr_index, data);
> +	struct msr_data msr;
> +	msr.data = data;
> +	msr.index = msr_index;
> +	msr.host_initiated = true;

false, this is guest instruction emulation.