Re: [PATCH v2 34/43] KVM: x86: Remove defunct pre_block/post_block kvm_x86_ops hooks

From: Maxim Levitsky
Date: Thu Oct 28 2021 - 11:47:11 EST


On Fri, 2021-10-08 at 19:12 -0700, Sean Christopherson wrote:
> Drop kvm_x86_ops' pre/post_block() now that all implementations are nops.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/include/asm/kvm-x86-ops.h | 2 --
> arch/x86/include/asm/kvm_host.h | 12 ------------
> arch/x86/kvm/vmx/vmx.c | 13 -------------
> arch/x86/kvm/x86.c | 6 +-----
> 4 files changed, 1 insertion(+), 32 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
> index cefe1d81e2e8..c2b007171abd 100644
> --- a/arch/x86/include/asm/kvm-x86-ops.h
> +++ b/arch/x86/include/asm/kvm-x86-ops.h
> @@ -96,8 +96,6 @@ KVM_X86_OP(handle_exit_irqoff)
> KVM_X86_OP_NULL(request_immediate_exit)
> KVM_X86_OP(sched_in)
> KVM_X86_OP_NULL(update_cpu_dirty_logging)
> -KVM_X86_OP_NULL(pre_block)
> -KVM_X86_OP_NULL(post_block)
> KVM_X86_OP_NULL(vcpu_blocking)
> KVM_X86_OP_NULL(vcpu_unblocking)
> KVM_X86_OP_NULL(update_pi_irte)
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 328103a520d3..76a8dddc1a48 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1445,18 +1445,6 @@ struct kvm_x86_ops {
> const struct kvm_pmu_ops *pmu_ops;
> const struct kvm_x86_nested_ops *nested_ops;
>
> - /*
> - * Architecture specific hooks for vCPU blocking due to
> - * HLT instruction.
> - * Returns for .pre_block():
> - * - 0 means continue to block the vCPU.
> - * - 1 means we cannot block the vCPU since some event
> - * happens during this period, such as, 'ON' bit in
> - * posted-interrupts descriptor is set.
> - */
> - int (*pre_block)(struct kvm_vcpu *vcpu);
> - void (*post_block)(struct kvm_vcpu *vcpu);
> -
> void (*vcpu_blocking)(struct kvm_vcpu *vcpu);
> void (*vcpu_unblocking)(struct kvm_vcpu *vcpu);
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index a24f19874716..13e732a818f3 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7462,16 +7462,6 @@ void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu)
> secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_ENABLE_PML);
> }
>
> -static int vmx_pre_block(struct kvm_vcpu *vcpu)
> -{
> - return 0;
> -}
> -
> -static void vmx_post_block(struct kvm_vcpu *vcpu)
> -{
> -
> -}
> -
> static void vmx_setup_mce(struct kvm_vcpu *vcpu)
> {
> if (vcpu->arch.mcg_cap & MCG_LMCE_P)
> @@ -7665,9 +7655,6 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
> .cpu_dirty_log_size = PML_ENTITY_NUM,
> .update_cpu_dirty_logging = vmx_update_cpu_dirty_logging,
>
> - .pre_block = vmx_pre_block,
> - .post_block = vmx_post_block,
> -
> .pmu_ops = &intel_pmu_ops,
> .nested_ops = &vmx_nested_ops,
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 909e932a7ae7..9643f23c28c7 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -9898,8 +9898,7 @@ static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
> {
> bool hv_timer;
>
> - if (!kvm_arch_vcpu_runnable(vcpu) &&
> - (!kvm_x86_ops.pre_block || static_call(kvm_x86_pre_block)(vcpu) == 0)) {
> + if (!kvm_arch_vcpu_runnable(vcpu)) {
> /*
> * Switch to the software timer before halt-polling/blocking as
> * the guest's timer may be a break event for the vCPU, and the
> @@ -9921,9 +9920,6 @@ static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
> if (hv_timer)
> kvm_lapic_switch_to_hv_timer(vcpu);
>
> - if (kvm_x86_ops.post_block)
> - static_call(kvm_x86_post_block)(vcpu);
> -
> if (!kvm_check_request(KVM_REQ_UNHALT, vcpu))
> return 1;
> }

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

Best regards,
Maxim Levitsky