From 071f24ad28cdcdfa544fdb79b1b1d2b423717a11 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 29 Aug 2024 21:35:54 -0700 Subject: KVM: Rename arch hooks related to per-CPU virtualization enabling Rename the per-CPU hooks used to enable virtualization in hardware to align with the KVM-wide helpers in kvm_main.c, and to better capture that the callbacks are invoked on every online CPU. No functional change intended. Suggested-by: Paolo Bonzini Signed-off-by: Sean Christopherson Reviewed-by: Kai Huang Message-ID: <20240830043600.127750-5-seanjc@google.com> Signed-off-by: Paolo Bonzini --- include/linux/kvm_host.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b23c6d48392f..4ceecba64f93 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1521,8 +1521,8 @@ static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {} #endif #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING -int kvm_arch_hardware_enable(void); -void kvm_arch_hardware_disable(void); +int kvm_arch_enable_virtualization_cpu(void); +void kvm_arch_disable_virtualization_cpu(void); #endif int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu); bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu); -- cgit v1.2.3-58-ga151 From b67107a251b01161956892352d53fb122346eda1 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 29 Aug 2024 21:35:58 -0700 Subject: KVM: Add arch hooks for enabling/disabling virtualization Add arch hooks that are invoked when KVM enables/disable virtualization. x86 will use the hooks to register an "emergency disable" callback, which is essentially an x86-specific shutdown notifier that is used when the kernel is doing an emergency reboot/shutdown/kexec. Add comments for the declarations to help arch code understand exactly when the callbacks are invoked. Alternatively, the APIs themselves could communicate most of the same info, but kvm_arch_pre_enable_virtualization() and kvm_arch_post_disable_virtualization() are a bit cumbersome, and make it a bit less obvious that they are intended to be implemented as a pair. Reviewed-by: Chao Gao Reviewed-by: Kai Huang Acked-by: Kai Huang Tested-by: Farrah Chen Signed-off-by: Sean Christopherson Message-ID: <20240830043600.127750-9-seanjc@google.com> Signed-off-by: Paolo Bonzini --- include/linux/kvm_host.h | 14 ++++++++++++++ virt/kvm/kvm_main.c | 14 ++++++++++++++ 2 files changed, 28 insertions(+) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4ceecba64f93..dfd6ad66efcc 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1521,6 +1521,20 @@ static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {} #endif #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING +/* + * kvm_arch_{enable,disable}_virtualization() are called on one CPU, under + * kvm_usage_lock, immediately after/before 0=>1 and 1=>0 transitions of + * kvm_usage_count, i.e. at the beginning of the generic hardware enabling + * sequence, and at the end of the generic hardware disabling sequence. + */ +void kvm_arch_enable_virtualization(void); +void kvm_arch_disable_virtualization(void); +/* + * kvm_arch_{enable,disable}_virtualization_cpu() are called on "every" CPU to + * do the actual twiddling of hardware bits. The hooks are called on all + * online CPUs when KVM enables/disabled virtualization, and on a single CPU + * when that CPU is onlined/offlined (including for Resume/Suspend). + */ int kvm_arch_enable_virtualization_cpu(void); void kvm_arch_disable_virtualization_cpu(void); #endif diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3a18da68b0ca..5f9a66df7bfb 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5581,6 +5581,16 @@ static DEFINE_PER_CPU(bool, virtualization_enabled); static DEFINE_MUTEX(kvm_usage_lock); static int kvm_usage_count; +__weak void kvm_arch_enable_virtualization(void) +{ + +} + +__weak void kvm_arch_disable_virtualization(void) +{ + +} + static int kvm_enable_virtualization_cpu(void) { if (__this_cpu_read(virtualization_enabled)) @@ -5680,6 +5690,8 @@ static int kvm_enable_virtualization(void) if (kvm_usage_count++) return 0; + kvm_arch_enable_virtualization(); + r = cpuhp_setup_state(CPUHP_AP_KVM_ONLINE, "kvm/cpu:online", kvm_online_cpu, kvm_offline_cpu); if (r) @@ -5710,6 +5722,7 @@ err_rebooting: unregister_syscore_ops(&kvm_syscore_ops); cpuhp_remove_state(CPUHP_AP_KVM_ONLINE); err_cpuhp: + kvm_arch_disable_virtualization(); --kvm_usage_count; return r; } @@ -5723,6 +5736,7 @@ static void kvm_disable_virtualization(void) unregister_syscore_ops(&kvm_syscore_ops); cpuhp_remove_state(CPUHP_AP_KVM_ONLINE); + kvm_arch_disable_virtualization(); } static int kvm_init_virtualization(void) -- cgit v1.2.3-58-ga151