Re: [PATCH v2 32/50] KVM: Drop kvm_arch_check_processor_compat() hook

From: Huang, Kai
Date: Fri Dec 02 2022 - 07:18:26 EST


On Wed, 2022-11-30 at 23:09 +0000, Sean Christopherson wrote:
> Drop kvm_arch_check_processor_compat() and its support code now that all
> architecture implementations are nops.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
> Reviewed-by: Eric Farman <farman@xxxxxxxxxxxxx> # s390
> Acked-by: Anup Patel <anup@xxxxxxxxxxxxxx>

For x86,

Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>

> ---
> 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 936ef7d1ea94..e915b1d9f2cd 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)
> {
> @@ -2273,7 +2268,7 @@ 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 01d0f9935e6c..f5b4ff6bfc89 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -440,11 +440,6 @@ 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 25b08b956888..7ad8252e92c2 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -262,11 +262,6 @@ 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);
> @@ -5716,7 +5711,7 @@ 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 d7ea1c1175c2..d9a54590591d 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -5103,8 +5103,8 @@ 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 8deb1bd60c10..b6f08a0a1435 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -8592,8 +8592,8 @@ 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 3571bc968cf8..566156b34314 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -12071,11 +12071,6 @@ 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 7dde28333e7c..616e8e90558b 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -953,8 +953,7 @@ 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);
> @@ -1460,7 +1459,6 @@ 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 a4a10a0b322f..3900bd3d75cb 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -5833,36 +5833,14 @@ 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)