Re: [PATCH 30/44] KVM: Drop kvm_arch_check_processor_compat() hook

[Anup Patel <anup@brainfault.org>]

On Thu, Nov 3, 2022 at 4:50 AM Sean Christopherson <seanjc@google.com> wrote:
>
> Drop kvm_arch_check_processor_compat() and its support code now that all
> architecture implementations are nops.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

For KVM RISC-V:
Acked-by: Anup Patel <anup@brainfault.org>

Thanks,
Anup

> ---
>  arch/arm64/kvm/arm.c       |  7 +------
>  arch/mips/kvm/mips.c       |  7 +------
>  arch/powerpc/kvm/book3s.c  |  2 +-
>  arch/powerpc/kvm/e500.c    |  2 +-
>  arch/powerpc/kvm/e500mc.c  |  2 +-
>  arch/powerpc/kvm/powerpc.c |  5 -----
>  arch/riscv/kvm/main.c      |  7 +------
>  arch/s390/kvm/kvm-s390.c   |  7 +------
>  arch/x86/kvm/svm/svm.c     |  4 ++--
>  arch/x86/kvm/vmx/vmx.c     |  4 ++--
>  arch/x86/kvm/x86.c         |  5 -----
>  include/linux/kvm_host.h   |  4 +---
>  virt/kvm/kvm_main.c        | 24 +-----------------------
>  13 files changed, 13 insertions(+), 67 deletions(-)
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 75c5125b0dd3..ed1836b6f044 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -63,11 +63,6 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
>         return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
>  }
>
> -int kvm_arch_check_processor_compat(void *opaque)
> -{
> -       return 0;
> -}
> -
>  int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
>                             struct kvm_enable_cap *cap)
>  {
> @@ -2268,7 +2263,7 @@ static __init int kvm_arm_init(void)
>          * FIXME: Do something reasonable if kvm_init() fails after pKVM
>          * hypervisor protection is finalized.
>          */
> -       err = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +       err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
>         if (err)
>                 goto out_subs;
>
> diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
> index 3cade648827a..36c8991b5d39 100644
> --- a/arch/mips/kvm/mips.c
> +++ b/arch/mips/kvm/mips.c
> @@ -135,11 +135,6 @@ void kvm_arch_hardware_disable(void)
>         kvm_mips_callbacks->hardware_disable();
>  }
>
> -int kvm_arch_check_processor_compat(void *opaque)
> -{
> -       return 0;
> -}
> -
>  extern void kvm_init_loongson_ipi(struct kvm *kvm);
>
>  int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
> @@ -1636,7 +1631,7 @@ static int __init kvm_mips_init(void)
>
>         register_die_notifier(&kvm_mips_csr_die_notifier);
>
> -       ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +       ret = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
>         if (ret) {
>                 unregister_die_notifier(&kvm_mips_csr_die_notifier);
>                 return ret;
> diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> index 87283a0e33d8..57f4e7896d67 100644
> --- a/arch/powerpc/kvm/book3s.c
> +++ b/arch/powerpc/kvm/book3s.c
> @@ -1052,7 +1052,7 @@ static int kvmppc_book3s_init(void)
>  {
>         int r;
>
> -       r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +       r = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
>         if (r)
>                 return r;
>  #ifdef CONFIG_KVM_BOOK3S_32_HANDLER
> diff --git a/arch/powerpc/kvm/e500.c b/arch/powerpc/kvm/e500.c
> index 0ea61190ec04..b0f695428733 100644
> --- a/arch/powerpc/kvm/e500.c
> +++ b/arch/powerpc/kvm/e500.c
> @@ -531,7 +531,7 @@ static int __init kvmppc_e500_init(void)
>         flush_icache_range(kvmppc_booke_handlers, kvmppc_booke_handlers +
>                            ivor[max_ivor] + handler_len);
>
> -       r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
> +       r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
>         if (r)
>                 goto err_out;
>         kvm_ops_e500.owner = THIS_MODULE;
> diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
> index 795667f7ebf0..611532a0dedc 100644
> --- a/arch/powerpc/kvm/e500mc.c
> +++ b/arch/powerpc/kvm/e500mc.c
> @@ -404,7 +404,7 @@ static int __init kvmppc_e500mc_init(void)
>          */
>         kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);
>
> -       r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
> +       r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
>         if (r)
>                 goto err_out;
>         kvm_ops_e500mc.owner = THIS_MODULE;
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 34278042ad27..51268be60dac 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -441,11 +441,6 @@ int kvm_arch_hardware_enable(void)
>         return 0;
>  }
>
> -int kvm_arch_check_processor_compat(void *opaque)
> -{
> -       return 0;
> -}
> -
>  int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
>  {
>         struct kvmppc_ops *kvm_ops = NULL;
> diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
> index 4710a6751687..34c3dece6990 100644
> --- a/arch/riscv/kvm/main.c
> +++ b/arch/riscv/kvm/main.c
> @@ -20,11 +20,6 @@ long kvm_arch_dev_ioctl(struct file *filp,
>         return -EINVAL;
>  }
>
> -int kvm_arch_check_processor_compat(void *opaque)
> -{
> -       return 0;
> -}
> -
>  int kvm_arch_hardware_enable(void)
>  {
>         unsigned long hideleg, hedeleg;
> @@ -110,6 +105,6 @@ static int __init riscv_kvm_init(void)
>
>         kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
>
> -       return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +       return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
>  }
>  module_init(riscv_kvm_init);
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 7c1c6d81b5d7..949231f1393e 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -254,11 +254,6 @@ int kvm_arch_hardware_enable(void)
>         return 0;
>  }
>
> -int kvm_arch_check_processor_compat(void *opaque)
> -{
> -       return 0;
> -}
> -
>  /* forward declarations */
>  static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
>                               unsigned long end);
> @@ -5654,7 +5649,7 @@ static int __init kvm_s390_init(void)
>         if (r)
>                 return r;
>
> -       r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
> +       r = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
>         if (r) {
>                 __kvm_s390_exit();
>                 return r;
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 368b4db4b240..99c1ac2d9c84 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -5144,8 +5144,8 @@ static int __init svm_init(void)
>          * Common KVM initialization _must_ come last, after this, /dev/kvm is
>          * exposed to userspace!
>          */
> -       r = kvm_init(NULL, sizeof(struct vcpu_svm),
> -                    __alignof__(struct vcpu_svm), THIS_MODULE);
> +       r = kvm_init(sizeof(struct vcpu_svm), __alignof__(struct vcpu_svm),
> +                    THIS_MODULE);
>         if (r)
>                 goto err_kvm_init;
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 26baaccb659a..25e28d368274 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -8562,8 +8562,8 @@ static int __init vmx_init(void)
>          * Common KVM initialization _must_ come last, after this, /dev/kvm is
>          * exposed to userspace!
>          */
> -       r = kvm_init(NULL, sizeof(struct vcpu_vmx),
> -                    __alignof__(struct vcpu_vmx), THIS_MODULE);
> +       r = kvm_init(sizeof(struct vcpu_vmx), __alignof__(struct vcpu_vmx),
> +                    THIS_MODULE);
>         if (r)
>                 goto err_kvm_init;
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 94831f1a1d04..5b7b551ae44b 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -12036,11 +12036,6 @@ void kvm_arch_hardware_disable(void)
>         drop_user_return_notifiers();
>  }
>
> -int kvm_arch_check_processor_compat(void *opaque)
> -{
> -       return 0;
> -}
> -
>  bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
>  {
>         return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 6c2a28c4c684..0b96d836a051 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -936,8 +936,7 @@ static inline void kvm_irqfd_exit(void)
>  {
>  }
>  #endif
> -int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
> -                 struct module *module);
> +int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module);
>  void kvm_exit(void);
>
>  void kvm_get_kvm(struct kvm *kvm);
> @@ -1444,7 +1443,6 @@ static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
>
>  int kvm_arch_hardware_enable(void);
>  void kvm_arch_hardware_disable(void);
> -int kvm_arch_check_processor_compat(void *opaque);
>  int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
>  bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu);
>  int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu);
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 17c852cb6842..dd13af9f06d5 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -5814,36 +5814,14 @@ void kvm_unregister_perf_callbacks(void)
>  }
>  #endif
>
> -struct kvm_cpu_compat_check {
> -       void *opaque;
> -       int *ret;
> -};
> -
> -static void check_processor_compat(void *data)
> +int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
>  {
> -       struct kvm_cpu_compat_check *c = data;
> -
> -       *c->ret = kvm_arch_check_processor_compat(c->opaque);
> -}
> -
> -int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
> -                 struct module *module)
> -{
> -       struct kvm_cpu_compat_check c;
>         int r;
>         int cpu;
>
>         if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL))
>                 return -ENOMEM;
>
> -       c.ret = &r;
> -       c.opaque = opaque;
> -       for_each_online_cpu(cpu) {
> -               smp_call_function_single(cpu, check_processor_compat, &c, 1);
> -               if (r < 0)
> -                       goto out_free_2;
> -       }
> -
>         r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
>                                       kvm_starting_cpu, kvm_dying_cpu);
>         if (r)
> --
> 2.38.1.431.g37b22c650d-goog
>