From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> Add arch hooks for reboot, suspend, resume, and CPU-online/offline events with empty stub functions. Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> --- include/linux/kvm_host.h | 6 +++++ virt/kvm/Makefile.kvm | 2 +- virt/kvm/kvm_arch.c | 44 ++++++++++++++++++++++++++++++ virt/kvm/kvm_main.c | 58 +++++++++++++++++++++++++--------------- 4 files changed, 88 insertions(+), 22 deletions(-) create mode 100644 virt/kvm/kvm_arch.c diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index eab352902de7..dd2a6d98d4de 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1448,6 +1448,12 @@ int kvm_arch_post_init_vm(struct kvm *kvm); void kvm_arch_pre_destroy_vm(struct kvm *kvm); int kvm_arch_create_vm_debugfs(struct kvm *kvm); +int kvm_arch_suspend(int usage_count); +void kvm_arch_resume(int usage_count); +int kvm_arch_reboot(int val); +int kvm_arch_online_cpu(unsigned int cpu, int usage_count); +int kvm_arch_offline_cpu(unsigned int cpu, int usage_count); + #ifndef __KVM_HAVE_ARCH_VM_ALLOC /* * All architectures that want to use vzalloc currently also diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm index 2c27d5d0c367..c4210acabd35 100644 --- a/virt/kvm/Makefile.kvm +++ b/virt/kvm/Makefile.kvm @@ -5,7 +5,7 @@ KVM ?= ../../../virt/kvm -kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o +kvm-y := $(KVM)/kvm_main.o $(KVM)/kvm_arch.o $(KVM)/eventfd.o $(KVM)/binary_stats.o kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o kvm-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o diff --git a/virt/kvm/kvm_arch.c b/virt/kvm/kvm_arch.c new file mode 100644 index 000000000000..4748a76bcb03 --- /dev/null +++ b/virt/kvm/kvm_arch.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * kvm_arch.c: kvm default arch hooks for hardware enabling/disabling + * Copyright (c) 2022 Intel Corporation. + * + * Author: + * Isaku Yamahata <isaku.yamahata@xxxxxxxxx> + * <isaku.yamahata@xxxxxxxxx> + */ + +#include <linux/kvm_host.h> + +/* + * Called after the VM is otherwise initialized, but just before adding it to + * the vm_list. + */ +__weak int kvm_arch_post_init_vm(struct kvm *kvm) +{ + return 0; +} + +__weak int kvm_arch_online_cpu(unsigned int cpu, int usage_count) +{ + return 0; +} + +__weak int kvm_arch_offline_cpu(unsigned int cpu, int usage_count) +{ + return 0; +} + +__weak int kvm_arch_reboot(int val) +{ + return NOTIFY_OK; +} + +__weak int kvm_arch_suspend(int usage_count) +{ + return 0; +} + +__weak void kvm_arch_resume(int usage_count) +{ +} diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 05ede37edc31..951f853f6ac9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -144,6 +144,7 @@ static int kvm_no_compat_open(struct inode *inode, struct file *file) #endif static int hardware_enable_all(void); static void hardware_disable_all(void); +static void hardware_disable_nolock(void *junk); static void kvm_io_bus_destroy(struct kvm_io_bus *bus); @@ -1097,15 +1098,6 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname) return ret; } -/* - * Called after the VM is otherwise initialized, but just before adding it to - * the vm_list. - */ -int __weak kvm_arch_post_init_vm(struct kvm *kvm) -{ - return 0; -} - /* * Called just after removing the VM from the vm_list, but before doing any * other destruction. @@ -5040,6 +5032,10 @@ static int kvm_online_cpu(unsigned int cpu) if (atomic_read(&hardware_enable_failed)) { atomic_set(&hardware_enable_failed, 0); ret = -EIO; + } else { + ret = kvm_arch_online_cpu(cpu, kvm_usage_count); + if (ret) + hardware_disable_nolock(NULL); } } mutex_unlock(&kvm_lock); @@ -5060,6 +5056,8 @@ static void hardware_disable_nolock(void *junk) static int kvm_offline_cpu(unsigned int cpu) { + int ret = 0; + mutex_lock(&kvm_lock); if (kvm_usage_count) { /* @@ -5069,10 +5067,15 @@ static int kvm_offline_cpu(unsigned int cpu) */ preempt_disable(); hardware_disable_nolock(NULL); + ret = kvm_arch_offline_cpu(cpu, kvm_usage_count); + if (ret) { + (void)hardware_enable_nolock(NULL); + atomic_set(&hardware_enable_failed, 0); + } preempt_enable(); } mutex_unlock(&kvm_lock); - return 0; + return ret; } static void hardware_disable_all_nolock(void) @@ -5130,6 +5133,8 @@ static int hardware_enable_all(void) static int kvm_reboot(struct notifier_block *notifier, unsigned long val, void *v) { + int r; + /* * Some (well, at least mine) BIOSes hang on reboot if * in vmx root mode. @@ -5138,8 +5143,15 @@ static int kvm_reboot(struct notifier_block *notifier, unsigned long val, */ pr_info("kvm: exiting hardware virtualization\n"); kvm_rebooting = true; + + /* This hook is called without cpuhotplug disabled. */ + cpus_read_lock(); + mutex_lock(&kvm_lock); on_each_cpu(hardware_disable_nolock, NULL, 1); - return NOTIFY_OK; + r = kvm_arch_reboot(val); + mutex_unlock(&kvm_lock); + cpus_read_unlock(); + return r; } static struct notifier_block kvm_reboot_notifier = { @@ -5728,6 +5740,8 @@ static void kvm_init_debug(void) static int kvm_suspend(void) { + int ret; + /* * The caller ensures that CPU hotlug is disabled by * cpu_hotplug_disable() and other CPUs are offlined. No need for @@ -5735,16 +5749,19 @@ static int kvm_suspend(void) */ lockdep_assert_not_held(&kvm_lock); - if (kvm_usage_count) { - preempt_disable(); + preempt_disable(); + if (kvm_usage_count) hardware_disable_nolock(NULL); - preempt_enable(); - } - return 0; + ret = kvm_arch_suspend(kvm_usage_count); + preempt_enable(); + + return ret; } static void kvm_resume(void) { + lockdep_assert_not_held(&kvm_lock); + if (kvm_arch_check_processor_compat()) /* * No warning here because kvm_arch_check_processor_compat() @@ -5752,12 +5769,11 @@ static void kvm_resume(void) */ return; /* FIXME: disable KVM */ - if (kvm_usage_count) { - lockdep_assert_not_held(&kvm_lock); - preempt_disable(); + preempt_disable(); + if (kvm_usage_count) hardware_enable_nolock((void *)__func__); - preempt_enable(); - } + kvm_arch_resume(kvm_usage_count); + preempt_enable(); } static struct syscore_ops kvm_syscore_ops = { -- 2.25.1