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

Maxim Levitsky
2021-11-03T17:03:49Z

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);