Re: [PATCH v5 3/7] nSVM: rename nested_load_control_from_vmcb12 in nested_copy_vmcb_control_to_cache

[Maxim Levitsky <mlevitsk@redhat.com>]

On Wed, 2021-11-03 at 10:05 -0400, Emanuele Giuseppe Esposito wrote:
> Following the same naming convention of the previous patch,
> rename nested_load_control_from_vmcb12.
> In addition, inline copy_vmcb_control_area as it is only called
> by this function.
> 
> _nested_copy_vmcb_control_to_cache() works with vmcb_control_area
> parameters and it will be useful in next patches, when we use
> local variables instead of svm cached state.

Tiny nitpick: usually when we have a patch which intends to just move/rename
things around, and should generate exact same machine code other
that some inlining/optimizations/etc, we usually mark this with
'No functional change intended', so that it is easier to spot
a mistake which only slighlty changes something.


The patch itself looks good.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

> 
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
>  arch/x86/kvm/svm/nested.c | 80 +++++++++++++++++++--------------------
>  arch/x86/kvm/svm/svm.c    |  2 +-
>  arch/x86/kvm/svm/svm.h    |  4 +-
>  3 files changed, 43 insertions(+), 43 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index ea64fea371c8..162b338a6c74 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -163,37 +163,6 @@ void recalc_intercepts(struct vcpu_svm *svm)
>  	vmcb_set_intercept(c, INTERCEPT_VMSAVE);
>  }
>  
> -static void copy_vmcb_control_area(struct vmcb_control_area *dst,
> -				   struct vmcb_control_area *from)
> -{
> -	unsigned int i;
> -
> -	for (i = 0; i < MAX_INTERCEPT; i++)
> -		dst->intercepts[i] = from->intercepts[i];
> -
> -	dst->iopm_base_pa         = from->iopm_base_pa;
> -	dst->msrpm_base_pa        = from->msrpm_base_pa;
> -	dst->tsc_offset           = from->tsc_offset;
> -	/* asid not copied, it is handled manually for svm->vmcb.  */
> -	dst->tlb_ctl              = from->tlb_ctl;
> -	dst->int_ctl              = from->int_ctl;
> -	dst->int_vector           = from->int_vector;
> -	dst->int_state            = from->int_state;
> -	dst->exit_code            = from->exit_code;
> -	dst->exit_code_hi         = from->exit_code_hi;
> -	dst->exit_info_1          = from->exit_info_1;
> -	dst->exit_info_2          = from->exit_info_2;
> -	dst->exit_int_info        = from->exit_int_info;
> -	dst->exit_int_info_err    = from->exit_int_info_err;
> -	dst->nested_ctl           = from->nested_ctl;
> -	dst->event_inj            = from->event_inj;
> -	dst->event_inj_err        = from->event_inj_err;
> -	dst->nested_cr3           = from->nested_cr3;
> -	dst->virt_ext              = from->virt_ext;
> -	dst->pause_filter_count   = from->pause_filter_count;
> -	dst->pause_filter_thresh  = from->pause_filter_thresh;
> -}
> -
>  static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
>  {
>  	/*
> @@ -317,15 +286,46 @@ static bool nested_vmcb_valid_sregs(struct kvm_vcpu *vcpu,
>  	return true;
>  }
>  
> -void nested_load_control_from_vmcb12(struct vcpu_svm *svm,
> -				     struct vmcb_control_area *control)
> +static
> +void _nested_copy_vmcb_control_to_cache(struct vmcb_control_area *to,
> +					struct vmcb_control_area *from)
>  {
> -	copy_vmcb_control_area(&svm->nested.ctl, control);
> +	unsigned int i;
> +
> +	for (i = 0; i < MAX_INTERCEPT; i++)
> +		to->intercepts[i] = from->intercepts[i];
> +
> +	to->iopm_base_pa        = from->iopm_base_pa;
> +	to->msrpm_base_pa       = from->msrpm_base_pa;
> +	to->tsc_offset          = from->tsc_offset;
> +	to->tlb_ctl             = from->tlb_ctl;
> +	to->int_ctl             = from->int_ctl;
> +	to->int_vector          = from->int_vector;
> +	to->int_state           = from->int_state;
> +	to->exit_code           = from->exit_code;
> +	to->exit_code_hi        = from->exit_code_hi;
> +	to->exit_info_1         = from->exit_info_1;
> +	to->exit_info_2         = from->exit_info_2;
> +	to->exit_int_info       = from->exit_int_info;
> +	to->exit_int_info_err   = from->exit_int_info_err;
> +	to->nested_ctl          = from->nested_ctl;
> +	to->event_inj           = from->event_inj;
> +	to->event_inj_err       = from->event_inj_err;
> +	to->nested_cr3          = from->nested_cr3;
> +	to->virt_ext            = from->virt_ext;
> +	to->pause_filter_count  = from->pause_filter_count;
> +	to->pause_filter_thresh = from->pause_filter_thresh;
> +
> +	/* Copy asid here because nested_vmcb_check_controls will check it.  */
> +	to->asid           = from->asid;
> +	to->msrpm_base_pa &= ~0x0fffULL;
> +	to->iopm_base_pa  &= ~0x0fffULL;
> +}
>  
> -	/* Copy it here because nested_svm_check_controls will check it.  */
> -	svm->nested.ctl.asid           = control->asid;
> -	svm->nested.ctl.msrpm_base_pa &= ~0x0fffULL;
> -	svm->nested.ctl.iopm_base_pa  &= ~0x0fffULL;
> +void nested_copy_vmcb_control_to_cache(struct vcpu_svm *svm,
> +				       struct vmcb_control_area *control)
> +{
> +	_nested_copy_vmcb_control_to_cache(&svm->nested.ctl, control);
>  }
>  
>  static void _nested_copy_vmcb_save_to_cache(struct vmcb_save_area_cached *to,
> @@ -691,7 +691,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu)
>  	if (WARN_ON_ONCE(!svm->nested.initialized))
>  		return -EINVAL;
>  
> -	nested_load_control_from_vmcb12(svm, &vmcb12->control);
> +	nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
>  	nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);
>  
>  	if (!nested_vmcb_valid_sregs(vcpu, &vmcb12->save) ||
> @@ -1438,7 +1438,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
>  	svm->nested.vmcb12_gpa = kvm_state->hdr.svm.vmcb_pa;
>  
>  	svm_copy_vmrun_state(&svm->vmcb01.ptr->save, save);
> -	nested_load_control_from_vmcb12(svm, ctl);
> +	nested_copy_vmcb_control_to_cache(svm, ctl);
>  
>  	svm_switch_vmcb(svm, &svm->nested.vmcb02);
>  	nested_vmcb02_prepare_control(svm);
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 6e5c2671e823..74d6db9017ea 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -4437,7 +4437,7 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
>  	 */
>  
>  	vmcb12 = map.hva;
> -	nested_load_control_from_vmcb12(svm, &vmcb12->control);
> +	nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
>  	nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);
>  	ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, false);
>  
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index 0897551d8868..a0609fe2e68c 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -502,8 +502,8 @@ int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
>  int nested_svm_exit_special(struct vcpu_svm *svm);
>  void nested_svm_update_tsc_ratio_msr(struct kvm_vcpu *vcpu);
>  void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier);
> -void nested_load_control_from_vmcb12(struct vcpu_svm *svm,
> -				     struct vmcb_control_area *control);
> +void nested_copy_vmcb_control_to_cache(struct vcpu_svm *svm,
> +				       struct vmcb_control_area *control);
>  void nested_copy_vmcb_save_to_cache(struct vcpu_svm *svm,
>  				    struct vmcb_save_area *save);
>  void nested_sync_control_from_vmcb02(struct vcpu_svm *svm);